Drought stress occurring during the reproductive growth stage leads to considerable reductions in crop production and has become an important limiting factor for food security globally. In order to explore the possible role of drought priming (pre-exposure of the plants to mild drought stress) on the alleviation of a severe drought stress event later in development, wheat plants were subjected to single or double mild drought episodes (soil relative water content around 35-40%) before anthesis and/or to a severe drought stress event (soil relative water content around 20-25%) 15 d after anthesis. Here, single or double drought priming before anthesis resulted in higher grain yield than in non-primed plants under drought stress during grain filling. The photosynthesis rate and ascorbate peroxidase activity were higher while malondialdehyde content was lower in primed plants than in the non-primed plants under drought stress during grain filling. Proteins in flag leaves differently expressed by ...
Addressing the risks to public health posed by ongoing drought in NSW requires an understanding of the links between drought, drought-related stress and the factors that influence this stress. Farmers are particularly at risk of drought-related stress and targeted programs are needed to support farmers whose families and communities are impacted by drought.. Our study published in the Medical Journal of Australia used data from the Australian Rural Mental Health Study to investigate drought-related stress in 664 farmers in NSW during the Millennium Drought (1997-2010). The Australian Rural Mental Health Study extended beyond 2010 meaning both wet and dry conditions were captured which allowed consideration of impacts to farmers mental health under different climate conditions.. We measured general psychological distress and two types of drought-related stress - personal and community. Personal drought-related stress includes worries and concerns farmers had about themselves and their families, ...
Drought stress is one of the serious problems that restricted agronomic plant production worldwide. In molecular level, the harmful effect of drought stress is mostly caused by producing of large amount of reactive oxygen species (ROS). Catalase and Metallothionein genes have a crucial role to mope the hydrogen peroxide (H2O2) resulting reducing oxidative damage. In this research the gene expression pattern of Catalase and Metallothionein was studied in response to drought stress treatments. The treatments included - 0.3 bar, - 0.9 bar, - 8 bar and -12 bar and wheat varieties included Zagros (drought tolerant), Moghan (semi- tolerant) and Tajan (drought sensitive). The amount of cellular oxidative levels (TBARM) increased steady by intensify of drought stress levels. Real time PCR analysis showed different expression pattern for catalase and metallothionein encoded genes. Catalase gene expression was increased during drought stress up to -8 bar and reduced in -12 bar treatment, in all cultivars
Drought is an important environmental stress limiting the productivity of major crops worldwide. Understanding drought tolerance and possible mechanisms for improving drought resistance is therefore a prerequisite to develop drought-tolerant crops that produce significant yields with reduced amounts of water. Brachypodium distachyon (Brachypodium) is a key model species for cereals, forage grasses and energy grasses. In this study, initial screening of a Brachypodium germplasm collection consisting of 138 different ecotypes exposed to progressive drought, highlighted the natural variation in morphology, biomass accumulation and responses to drought stress. A core set of ten ecotypes, classified as being either tolerant, susceptible or intermediate, in response to drought stress, were exposed to mild or severe (respectively 15% and 0% soil water content) drought stress and phenomic parameters linked to growth and colour changes were assessed. When exposed to severe drought stress, phenotypic data and
What is a drought?. While it is relatively easy to define what a hurricane or earthquake is, defining a drought is more subjective. Droughts do not have the immediate effects of floods, but sustained droughts can cause economic stress throughout an area. The word drought has various meanings, depending on a persons perspective. To a farmer, a drought is a period of moisture deficiency that affects the crops under cultivation-even two weeks without rainfall can stress many crops during certain periods of the growing cycle. To a meteorologist, a drought is a prolonged period when precipitation is less than normal. To a water manager, a drought is a deficiency in water supply that affects water availability and water quality. To a hydrologist, a drought is an extended period of decreased precipitation and streamflow. Droughts in Puerto Rico have severely affected municipal and industrial water supplies, agriculture, stream water quality, recreation at major reservoirs, hydropower generation, and ...
Drought is one of the most important environmental stresses that effects crop productivity in many agricultural regions. Sunflower is tolerant to drought conditions but the mechanisms involved in this tolerance remain unclear at the molecular level. The aim of this study was to characterize and integrate transcriptional and metabolic pathways related to drought stress in sunflower plants, by using a system biology approach. Our results showed a delay in plant senescence with an increase in the expression level of photosynthesis related genes as well as higher levels of sugars, osmoprotectant amino acids and ionic nutrients under drought conditions. In addition, we identified transcription factors that were upregulated during drought conditions and that may act as hubs in the transcriptional network. Many of these transcription factors belong to families implicated in the drought response in model species. The integration of transcriptomic and metabolomic data in this study, together with ...
In this study, responses of rice under drought stress correlating with changes in chemical compositions were examined. Among 20 studied rice cultivars, Q8 was the most tolerant, whereas Q2 was the most susceptible to drought. Total phenols, total flavonoids, and antioxidant activities, and their accumulation in water deficit conditions were proportional to drought resistance levels of rice. In detail, total phenols and total flavonoids in Q8 (65.3 mg gallic acid equivalent (GAE) and 37.8 mg rutin equivalent (RE) were significantly higher than Q2 (33.9 mg GAE/g and 27.4 mg RE/g, respectively) in both control and drought stress groups. Similarly, the antioxidant activities including DPPH radical scavenging, β-carotene bleaching, and lipid peroxidation inhibition in Q8 were also higher than in Q2, and markedly increased in drought stress. In general, contents of individual phenolic acids in Q8 were higher than Q2, and they were significantly increased in drought stress to much greater extents than in Q2.
Plants as sessile organisms are susceptible to many environmental stresses such as drought, and salinity. They have therefore evolved mechanisms to acclimate and tolerate environmental stresses. Knowledge of the molecular aspects of abiotic stress gleaned from extensive studies in Arabidopsis has provided much information on the complex processes underlying plant response to abiotic stresses. Nevertheless, there is a need for integration of the knowledge gained and a systematic molecular genetic dissection of the complex responses to abiotic stress. In this study in Arabidopsis, comparative expression profiling analysis of progressive (pDr) and moderate (mDr) drought treatments revealed common drought responses, as well as treatment specific signatures responses to drought stress. Under prolonged moderate drought plants develop different mechanisms for acclimation: induction of cell wall loosening at early stage, and a change in hormonal balance (ABA: JA) at late stage of moderate drought. ...
The development of new tools that provide timely agricultural drought risk assessment is essential for improving drought preparedness and response. This thesis developed an operational model framework to assess real-time agricultural drought risk on the Canadian prairies, as related to spring wheat crop yield. The agricultural drought risk assessment (ADRA) model integrates multiple drought indices including the Standardized Precipitation Index, the Palmer Drought Severity Index and the Palmer Moisture Anomaly Index. Drought risk is assessed at the beginning of each month before and during the growing season using principal component analysis and multiple regression analysis. The performance of the model was validated by cross-validation. The results showed that drought risk can be detected at pre-planting ; the assessment accuracy improves as the crop develops, and the most accurate assessment can be achieved at the beginning of August (average R2 = 0.61). The model performed best in regions ...
The decline in SVC indicated that the drought treatment imposed severe water stress on plants. SVC in a 20-cm soil depth declined to ≈2% after 14 d of drought treatment. Our results demonstrate that GABA- (50 mm) treated perennial ryegrass maintained significantly higher RWC under drought stress than non-treated plants. RWC in leaves is a measure of internal water status during drought stress (Matin et al., 1989). The results suggest that GABA-treated perennial ryegrass plants were better able to maintain water under drought stress. The function of GABA as a compatible osmolyte under osmotic stress has been proposed by Shelp et al. (1999). Osmolyte accumulation in plant cells results in maintenance of cell turgor pressure and also protects cell membranes, protein, and metabolic machinery from cell dehydration (Hare et al., 1998; Ingram and Bartels, 1996; Rathinasabapathi, 2000). Two recent studies demonstrated that GABA was differentially accumulated in hybrid bermudagrass (Cynodon dactylon × ...
The Sahel has long experienced a series of historic droughts, dating back to at least the 17th century. The Sahel region is a climate zone sandwiched between the African Savannah grasslands to the south and the Sahara desert to the north, across West and Central Africa. While the frequency of drought in the region is thought to have increased from the end of the 19th century, three long droughts have had dramatic environmental and societal effects upon the Sahel nations. Famine followed severe droughts in the 1910s, the 1940s, and the 1960s, 1970s and 1980s, although a partial recovery occurred from 1975-80. The most recent drought occurred in 2012. While at least one particularly severe drought has been confirmed each century since the 17th century, the frequency and severity of recent Sahelian droughts stands out. Famine and dislocation on a massive scale-from 1968 to 1974 and again in the early and mid-1980s-was blamed on two spikes in the severity of the 1960-1980s drought period. From the ...
Drought stress is one of the major abiotic stresses that are a threat to crop production worldwide. Drought stress impairs the plants growth and yield. Therefore, the aim of the present experiment was to select the tolerant genotype/s on the basis of moprpho-physiological and biochemical characteristics of 10 Vicia faba genotypes (Zafar 1, Zafar 2, Shebam, Makamora, Espan, Giza Blanka, Giza 3, C4, C5 and G853) under drought stress. We studied the effect of different levels of drought stress i.e., (i) normal irrigation (ii) mild stress (iii) moderate stress, and (iv) severe stress on plant height (PH) plant−1, fresh weight (FW) and dry weight (DW) plant−1, area leaf−1, leaf relative water content (RWC), proline (Pro) content, total chlorophyll (Total Chl) content, electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (H2O2) content, and activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) of genotypes of faba bean. Drought stress reduced all growth
BACKGROUND: Soybean is an important crop that provides valuable proteins and oils for human use. Because soybean growth and development is extremely sensitive to water deficit, quality and crop yields are severely impacted by drought stress. In the face of limited water resources, drought-responsive genes are therefore of interest. Identification and analysis of dehydration- and rehydration-inducible differentially expressed genes (DEGs) would not only aid elucidation of molecular mechanisms of stress response, but also enable improvement of crop stress tolerance via gene transfer. Using Digital Gene Expression Tag profiling (DGE), a new technique based on Illumina sequencing, we analyzed expression profiles between two soybean genotypes to identify drought-responsive genes.. RESULTS: Two soybean genotypes - drought-tolerant Jindou21 and drought-sensitive Zhongdou33 - were subjected to dehydration and rehydration conditions. For analysis of DEGs under dehydration conditions, 20 cDNA libraries ...
ψw can be regarded as an indicator to effectively assess water status of plants (Lima et al., 2002). In the present study, ψw decreased with the degree and duration of drought stress treatments (Fig. 1). Gas exchange, which was PN, Gs and E decreased significantly and they were closely related to the degree and duration of drought stress (Fig. 2). These parameters were all found to have a strong relationship with ψw (Fig. 3). Besides the linear correlation between PN and ψw (Fig. 3A; Šimpraga et al., 2011; Sun et al., 2013), a simple positive regression correlation was also found between Gs or E and ψw (Fig. 3B,C). At the earlier stage of drought stress, the plummet in Gs suggests that a reduction in stomatal conductance can have protective effects because it allows the plant to save water and to improve its efficient use (Chaves et al., 2009). As some studies indicated before, the decrease in photosynthesis is usually caused by stomatal limitation under mild to moderate drought condition ...
Scoffoni et al. determined the physiological drought tolerance and architecture of 10 woody species. The authors test key components of leaf venation architecture to understand the underlying leaf structural mechanisms for drought tolerance. Most work on drought tolerance focuses on stems and highlight xylem geometries, but the authors show that the density of veins in a leaf are the best correlate with its physiological tolerance of drought. High vein density provides insurance against embolism and allows water to continue to be supplied to areas adjacent to veins that have experienced embolisms that necessarily accompany low water potentials. ...
Vegetation Drought Response Index (VegDRI). Index name: Vegetation Drought Response Index (VegDRI).. Ease of use: Green.. Origins: Developed by a team of scientists from NDMC, the United States Geological Surveys Earth Resources Observation and Science Center, and the United States Geological Survey Flagstaff Field Center.. Characteristics: Developed as a drought index that was intended to monitor drought-induced vegetation stress using a combination of remote sensing, climate-based indicators, and other biophysical information and land-use data.. Input parameters: SPI, PDSI, percentage annual seasonal greenness, start of season anomaly, land cover, soil available water capacity, irrigated agriculture and defined ecological regions. As some of the inputs are derived variables, additional inputs are needed.. Applications: Used mainly as a short-term indicator of drought for agricultural applications.. Strengths: An innovative and integrated technique using both surface and remotely sensed data ...
The geo-climatic conditions of South and South-East Asian countries are diverse and vulnerable to multiple natural hazards such as drought. Drought evolves over months or even years, affects a large spatial extent and causes enormous damages. Drought Risk Management in South and South-East Asia is a comprehensive reference on overall perspectives and scenarios on drought risk mitigation and management, based on researches and case studies from South and South-East Asian countries. Drought management is a complex area of work that requires active and continuous participation of the national, provincial and local governments, multiple ministries, and divisions. This book demonstrates the best practices of socio-economic and technological interventions to enhance drought risk management, which will help to develop plans and policies, and their implementation to reduce the impact of droughts. It also offers views of field practitioners on impacts of the interventions practised at the national, ...
Interactions between biogenic monoterpenes and drought stress remain poorly understood and characterised. Even the nature of the response of biogenic monoterpene emissions to water limitation is controversial, possibly depending on the severity, intensity and duration of the drought. Whether monoterpenes regulate plant physiological response to drought stress is currently unknown. In this research, 6-week-old Ailsa Craig wild-type (WT) and ABA-deficient (notabilis) tomatoes were either well-watered or exposed to deficit irrigation (by watering pots with 25% of daily evapotranspiration) in a factorial combination with selected-monoterpenes applied exogenously as a foliar spray. Both genotypes showed similar physiological and biochemical responses to water deficit. Compared to well-watered controls, drought stress significantly reduced net photosynthesis rate and stomatal conductance, increased hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations, and also significantly inhibited PSII ...
SANTOS, Álvaro de Oliveira et al. Grain yield, anthesis-silking interval and drought tolerance indices of tropical maize hybrids. Crop Breed. Appl. Biotechnol. [online]. 2020, vol.20, n.1, e176020110. Epub 27-Mar-2020. ISSN 1984-7033. https://doi.org/10.1590/1984-70332020v20n1a10.. Water deficit stress is the abiotic factor with the highest impact on crop yield. The objective of this study was to evaluate grain yield (GY), the anthesis-silking interval (ASI) and drought tolerance indices in maize hybrids. We evaluated GY and the ASI of 86 hybrids under two moisture levels (normal irrigation and water stress) for three consecutive years. The stress susceptibility index, water stress tolerance, drought resistance coefficient, drought resistance index, stress tolerance index and harmonic mean were evaluated. There were significant hybrid x environment interactions for GY and the ASI. Differences in the ASI among environments ranged from 0 to 5 days. The hybrids P3862, 1I873, 1I923, 1I862 and ...
Initial physiological adjustments in response to drought stress lead to drastic changes in gene expression. The traditional approaches of assessing such drought-induced changes in gene expression involve measuring the differences in mRNA levels of one or few genes at a time. DNA expression microarray technology is a powerful tool that can monitor changes in expression of a large number of genes simultaneously. Expression microarrays also provide new insights into physiological and biochemical pathways of drought tolerance, and thus can lead to identification of novel candidate genes that can rapidly advance breeding for drought tolerance. This review describes the basic principles and potential applications of gene expression microarrays in understanding and improving drought tolerance in plants. A case study is presented involving hybridization of field-grown panicle samples from drought tolerant and susceptible rice germplasm targets with probes from a normalized panicle cDNA library. Results ...
Analysis - New research confirms that extreme droughts amid the deepening climate crisis are forcing nocturnal aardvarks in the Kalahari to feed and forage when the suns up -- but even so, their ant and termite food sources are dying out as the vegetation they survive on is affected by the droughts.
Histone acetylation is one of the vital reversible modifications of chromatin structure that regulates gene expression in eukaryotes. Histone acetyltransferases (HATs) and histone deacetylases (HDACs) maintain the homeostasis of histone acetylation. Studies in Arabidopsis have revealed that HATs are involved in plant responses to various stresses including light, temperature, salt and ABA. Drought stress, a very common environmental stress, could cause a range of physiological and biochemical responses in plants involving HATs. Eight HATs in four different families (CBP, GNAT, MYST, and TAFII250 family) are known in rice. In this research, four OsHATs, one from each family, were chosen based on in silico domain and promoter analysis for their response under drought conditions. Drought stress was introduced to two-leaf-stage rice seedlings. The effectiveness of drought treatment was confirmed by the measurement of relative water content (RWC). Real-time quantitative polymerase chain reaction ...
To investigate the interactive effects of drought, heat and elevated atmospheric CO2 concentration ([CO2]) on plant water relations and grain yield in wheat, two wheat cultivars with different drought tolerance (Gladius and Paragon) were grown under ambient and elevated [CO2], and were exposed to post-anthesis drought and heat stress. The stomatal conductance, plant water relation parameters, abscisic acid concentration in leaf and spike, and grain yield components were examined. Both stress treatments and elevated [CO2] reduced the stomatal conductance, which resulted in lower leaf relative water content and leaf water potential. Drought induced a significant increase in leaf and spike abscisic acid concentrations, while elevated [CO2] showed no effect. At maturity, post-anthesis drought and heat stress significantly decreased the grain yield by 21.3%-65.2%, while elevated [CO2] increased the grain yield by 20.8% in wheat, which was due to the changes of grain number per spike and thousand ...
Drought has dramatic negative effects on plants growth and crop productivity. Although some of the responses and underlying mechanisms are still poorly understood, there is increasing evidence that drought may have a negative effect on photosynthetic capacity. Biochemical models of leaf photosynthesis coupled with models of radiation transfer have been widely used in ecophysiological studies, and, more recently, in global change modeling. They are based on two fundamental relationships at the scale of the leaf: (i) nitrogen content-light exposure and (ii) photosynthetic capacity nitrogen content. Although drought is expected to increase in many places across the world, such models are not adapted to drought conditions. More specifically, the effects of drought on the two fundamental relationships are not well documented. The objective of our study was to investigate the effects of a long-term drought imposed slowly on the nitrogen content and photosynthetic capacity of leaves similarly exposed ...
In contrast to wild species, drought-tolerance in crops requires a fully functional metabolism during drought (particularly photosynthetic processes). However, the link between drought-tolerance, photosynthetic regulation during drought, and the associated transcript and metabolic foundation, remains largely unknown. For this study, we used two rice cultivars with contrasting drought-tolerance (the drought-intolerant cultivar IRAT109 and the drought-tolerant cultivar IAC1246) to explore transcript and metabolic responses to long-term drought. The drought-tolerant cultivar represented higher osmotic adjustment and antioxidant capacity, as well as higher relative photosynthesis rate under a progressive drought stress occurred in a modified field with shallow soil-layers. A total of 4059 and 2677 differentially expressed genes (DEGs) were identified in IRAT109 and IAC1246 between the drought and well-watered conditions, respectively. A total of 69 and 47 differential metabolites (DMs) were identified
by David Hart. An extended drought in parts of the United States has been characterized as an act of God, or somehow the result of our own doings. Maybe the drought is just a terrible stroke of bad luck.. Whatever the cause, much of the country remains locked in an epic drought. The impacts of the drought on people have made national headlines. The impacts on wildlife are often even more harsh.. California is in the midst of its worst drought on record. Experts say it could last for several more years. Numerous reservoirs in Texas are just a fraction of their normal volume, and farmers in parts of Kansas, Oklahoma and Colorado are struggling to survive.. Food prices are up, water tables are down, and churches throughout the west are filled with voices praying for rain.. Life during a drought may be hard for humans, but its hell for wildlife. Virtually every species of bird, fish and mammal that is suffering through a prolonged dry spell is facing population declines. Nowhere is that more ...
An unprecedented 82 percent of California is in an extreme drought, according to a 2014 U.S. Drought Monitor report. Of that, 58 percent of the state is in an exceptional drought - the driest conditions possible. Record-low rainfall has sent rivers, lakes and water reservoirs to their lowest levels in decades-threatening the water supply of many cities. The unusually dry conditions have increased the risk of wildfires, which have already ravaged parts of the state - most recently an area near Yosemite National Park. But the droughts biggest victim could be Californias Central Valley, the source of fully half the nations fruits and vegetables, where roughly 500,000 acres of farmland have been left barren this season because of a lack of water. In three of the hardest-hit counties - Fresno, Kern and Tulare - farmers are worried the drought could drive them out of business. (Photos by Holly Bailey/Yahoo News ...
Food crisis is a major concern in Egypt, where drought and saline soils are ubiquitous. Wheat is a staple food in Egypt, which is only moderately tolerant to drought and salinity. Due to its rapidly increasing demand, there is an urgent need in Egypt to enhance wheat yields under drought and salinity conditions. Improving salinity or/and drought tolerance of genotypes is inhibited by a lack of efficient evaluation methods. High throughput precision phenotyping provides an innovative technology to screen for enhanced salt or drought tolerance from a large of number of genotypes under field conditions and can have immediate value to plant breeding. Therefore, we have tested several wheat phenotyping techniques i.e., canopy temperature (CT), spectral reflectance (SR), chlorophyll content (SPAD value), crop ground cover, relative water content (RWC), Water soluble carbohydrates (WSC), leaf area index (LAI), crop morphological traits, and grain wheat yield and yield components. We documented strong ...
New research has questioned the consensus among many scientists that climate change is leading to a global increase in drought levels. The research has wide implications for how we predict the impacts of, and adapt to, climate change, concluding we need to take a much more regional approach to the issue.. The paper, Little change in global drought over the past 60 years, was completed by Dr Michael Roderick from the Australian National University, and Dr Justin Sheffield and Professor Eric Wood from Princeton University. Conducting an extensive review of data, the team found that global drought levels have not significantly increased over the past 60 years.. Roderick says the trend can be seen both globally, and within Australia. Our new model shows that over the past 60 years, weve got a slight increase in drought in eastern part of Australia and a slight increase in drought in the south-west. However, we also have a very large decrease in drought over much of South Australia, Northern ...
Several regions throughout our County are currently experiencing drought conditions. These dry spells pose some unique healthcare and management challenges for horses. Whether it is stress from heat and blowing dust, changing feeds or dwindling water supplies, the additive stresses from drought can cause potentially serious health problems for horses. Understanding and anticipating these problems will help maintain your horses health and welfare during this stressful time.. Horses that are stressed for any reason, including drought, benefit from good basic care. It is important to ensure that all horses are properly vaccinated and dewormed. In addition, stressed horses require the other basics, like good shelter, nutrition, hoof care, and fresh water.. Horses that are normally maintained on dry-land pasture are affected most by drought, as their feed supply dwindles and their management requires change. Any grass that is still present on pastures is usually severely drought-stressed. Under ...
Stanford scientists have now shown that may be possible in some instances - the researchers have identified a new kind of landfalling drought that can potentially be predicted before it impacts people and ecosystems on land. They found that these droughts, which form over the ocean and then migrate landward, can cause larger and drier conditions than droughts that occur solely over the land. Of all the droughts affecting land areas worldwide from 1981 to 2018, roughly one in six were landfalling droughts, according to the study published Sept. 21 in Water Resources Research.. We normally dont think about droughts over the ocean - it may even sound counterintuitive. But just as over land, there can be times where large regions in the ocean experience less rainfall than normal, said lead author Julio Herrera-Estrada, a research collaborator with Water in the West who conducted research for the study while he was a postdoctoral researcher at Stanfords School of Earth, Energy & Environmental ...
The present experiment was carried out at the Department of Genetics and Plant Breeding, Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India to study the effect of imposed drought on relative water content, chlorophyll content and proline accumulation in five drought tolerant (PL-406, IPL-324, LL-1146, IPL-325, K-75) and five drought sensitive (L1112-20, LP-112, ILL-10803, KLS-113, KLS-107) genotypes of lentil (Lens culinaris Medik.). For this purpose, the genotypes were grown under both control (0.0 bar) and drought stress (-9 bar) condition by using PEG- 6000 as osmoticum. The experiment was laid out in an asymmetrical factorial completely randomized design with three replications. Roots, shoots and leaves of ten days old seedlings were harvested and physiological and biochemical analyses were carried out for the above parameters. From the study it was revealed that relative water content and chlorophyll content (chl a, Chl b, total Chl) were reduced, while proline content was increased ...
Drought is one of the most important abiotic stresses causing drastic reductions in yield in rainfed rice environments. The suitability of grain yield (GY) under drought as a selection criterion has been reported in the past few years. Most of the quantitative trait loci (QTLs) for GY under drought in rice reported so far has been in the background of low-yielding susceptible varieties. Such QTLs have not shown a similar effect in multiple high- yielding drought-susceptible varieties, thus limiting their use in marker-assisted selection. Genetic control of GY under reproductive-stage drought stress (RS) in elite genetic backgrounds was studied in three F3:4 mapping populations derived from crosses of N22, a drought-tolerant aus cultivar, with Swarna, IR64, and MTU1010, three high-yielding popular mega-varieties, with the aim to identify QTLs for GY under RS that show a consistent effect in multiple elite genetic backgrounds. Three populations were phenotyped under RS in the dry seasons (DS) of 2009 and
Flavonoids are major secondary metabolites in plants, which play important roles in maintaining the cellular redox balance in cells. Chalcone synthase (CHS) is the key enzyme in the flavonoids biosynthesis pathway, and has been proved to monitor the changes to drought stress tolerance. In this work, we overexpressed a CHS gene in tobacco (Nicotiana tabacum). The transgenic tobacco plants were more tolerant than the control plants to drought stress. The transcription levels of the key genes involved in the flavonoids pathway and the contents of seven flavonoids were also significantly raised in the transgenic tobacco plants. In addition, overexpression of the CHS gene lead to a lower concentration of the oxidative stress product malondialdehyde. Overall, the NtCHS gene studied in this work was considered as a candidate gene for genetic engineering to enhance drought tolerance of plants and improve response to oxidative stress.
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In order to effectively mitigate against drought, the root causes need to be addressed. Drought management is too often restricted to treating the symptoms, often when it is too late and when only a relief function can be performed.. As can be seen from the variety of factors which are quoted above as causing or exacerbating drought conditions, a multi-sectoral approach needs to be adopted which involves a wide variety of different government and other parties. Advocacy is required to ensure that these different bodies understand the impact of their policies on conditions of water scarcity and drought vulnerability. It is therefore necessary to give attention to the policies of several government departments at both national and provincial level. Local Government plays a critical role in disaster relief, particularly in the mobilisation of local resources.. In terms of the directly water related elements of drought policy, the Department of Water Affairs and Forestry obviously plays an ...
In leaf, after forty minutes of dehydration, approximately two hundred genes showed at least 8-fold induction in mRNA levels (Additional file 5: Table S4). This number increased to over eight hundred after four hours. The up-regulated genes at the early time points included a large percentage of signalling molecules such as transcription factors, protein kinases, F Box proteins, and phosphatases (Additional file 5: Table S4). Over the time course of drought stress, the most strongly up-regulated gene in tobacco leaves also encodes a signalling molecule, a U-Box E3 ubiquitin ligase that we have called Ubiquitin Protein Ligase Like 1 (NtUPLL1) (Additional file 5: Table S4). The level of NtUPLL1 mRNA increases 52-fold after 40 minutes and over 290-fold by the four hour time point. NtUPLL1 and the closely related NtUPLL2 are similar to the Arabidopsis U-Box E3 ubiquitin ligases AtPUB18 and AtPUB19 that regulate ABA-mediated stomatal closure and drought stress responses [58].. At the later time ...
Only about 1 percent of the country was severely to extremely wet for the year. We had such widespread drought, it just exaggerated the impacts and drove prices for commodities higher, said Colorado State climatologist Nolan Doesken.. What made 2012 one for the record books actually started in 2011, when a drought in the southern U.S. crept into Colorado and the Midwest, setting the stage for disaster, Doesken said. March 2012 arrived with blustery winds and bone-dry conditions, sparking wildfires much earlier than many could imagine during a time when the area typically sees its rains for the year. Add in a blazing month of June and a relentless summer, and the situation worsened with uncertainty looming for 2013. It will take sopping spring rains in addition to a heavy snowpack to fix the soil and promote grass growth, Doesken said.. Itll be tough with it being so large in area, he said of the drought. Itll be unlikely that all the areas will recover as we move into next spring. ...
In order to test the hypothesis that multiple integrated root phenotypes would co-optimize drought tolerance, we phenotyped the root anatomy and architecture of 400 mature maize genotypes under well-watered and water-stressed conditions in the field. We found substantial variation in all 23 root phenes measured. A phenotypic bulked segregant analysis revealed that bulks representing the best and worst performers in the field displayed distinct root phenotypes. In contrast to the worst bulk, the root phenotype of the best bulk under drought consisted of greater cortical aerenchyma formation, more numerous and narrower metaxylem vessels, and thicker nodal roots. Partition against medians (PAM) clustering revealed several clusters of unique root phenotypes related to plant performance under water stress. Clusters associated with improved drought tolerance consisted of phene states that likely enable greater soil exploration by reallocating internal resources to greater root construction (increased ...
Reduced nitric oxide levels during drought stress promote drought tolerance in barley and is associated with elevated polyamine biosynthesis ...
LUBBOCK - Weather officials said Wednesday they considered reclassifying parts of North Texas into the least severe stage of drought but held off because recent rains havent boosted lakes levels. Bone-dry soil suffering from the states worst single-year drought is sucking up the rainfall before it runs into reservoirs in the Dallas-Fort Worth area and parts of northeast Texas, National Weather Service meteorologist Victor Murphy said. Data is submitted Tuesday mornings and the U.S. Drought Monitor map is released Thursday. Murphy says recent rains will help drought conditions in the short term, but the precipitation forecast for coming months remains bleak. The current drought started last fall with the arrival of the La Nina weather condition that causes below-normal rainfall. Hundreds of wildfires have blackened some 6,000 square miles and destroyed more than 2,700 homes in the state since the fire season started nearly a year ago.
The aim of this study is to compare the tolerance mechanisms of two industrial tomato varieties (X5671R and 5MX12956) under drought stress. 14 days-old tomato seedlings were subjected to 7 days-long drought stress by withholding irrigation. The effects of stress were determined by enzymatic and non-enzymatic parameters. The physiological damages were evaluated via lipid peroxidation ratio, total protein content, relative water content, chlorophyll content and proline accumulation. Enzymatic responses were determined by biochemical analysis and electrophoresis of SOD, APX, POX and CAT enzymes. Relative water contents of X5671R and 5MX12956 varieties at 7th day of drought were decreased to 8.4 and 12.2%, respectively. Applied drought decreased all photosynthetic pigments of X5671R and 5MX12956 varieties during the treatment period significantly comparing to the Day 0 as the control. Total protein content, lipid peroxidation and proline accumulation presented increased values in both varieties in
No two states experience the same set of impacts during a drought. We developed tables of impacts reported during past droughts in each state for each level of drought on the U.S. Drought Monitor. These state-specific possible impacts complement the general, national possible impacts column of the U.S. Drought Monitor Classification Scheme. ...
Considerable amounts and varieties of biogenic volatile organic compounds (BVOCs) are exchanged between vegeta-tion and the surrounding air. These BVOCs play key ecological and atmospheric roles that must be adequately repre-sented for accurately modeling the coupled biosphere-atmosphere-climate earth system. One key uncertainty in existing models is the response of BVOC fluxes to an important global change process: drought. We describe the diur-nal and seasonal variation in isoprene, monoterpene, and methanol fluxes from a temperate forest ecosystem before, during, and after an extreme 2012 drought event in the Ozark region of the central USA. BVOC fluxes were domi-nated by isoprene, which attained high emission rates of up to 35.4 mg m -2h -1 at midday. Methanol fluxes were characterized by net deposition in the morning, changing to a net emission flux through the rest of the daylight hours. Net flux of CO 2 reached its seasonal maximum approximately a month earlier than isoprenoid fluxes, ...
The California-Nevada Drought Early Warning System (CA-NV DEWS) May 2017 Drought & Climate Outlook Webinar is part of a series of regular drought and climate outlook webinars designed to provide stakeholders and other interested parties in the region with timely information on current drought status and impacts, as well as a preview of current and developing climatic events (i.e. El Niño and La Niña). The webinar takes place at 11 a.m. PDT, Tuesday May 30, 2017. ...
1. Introduction. Drought is a worldwide problem, and the study of drought has become one of the main research directions of global plant biology. In particular, great effort has been expended to develop drought-resistant plants by producing transgenic plants using different types of gene technologies, or genotypes possessing full physiological potential under limited soil water conditions (Casadebaig et al., 2008; Hong-Bo et al., 2006; Stella and Christoph, 2006; Sang-Eun et al., 2005). As a result of this research, the introduction of drought-resistant transgenic plants for commercial use has also become possible (Hilbeck et al., 2005).. Thus, a deeper understanding of plant physiological mechanisms operating under drought conditions is needed. Drought resistance in plants involves many biochemical, molecular and structural mechanisms, including the biosynthesis of different biomolecules (Bajguz and Hayat, 2009; Hong-Bo et al., 2006; Fiehn, 2002). For example, one well-known response of plants ...
Across a wide range of environmental conditions, forest types and tree species we found carbon isotope ratios of wood to be a strong and reliable indicator of past drought occurrence (Fig. 2a). However, despite this clear physiological signal of drought on δ13C, we only found a weak and context-dependent effect of these same drought events on tree growth (Fig. 2b). Previous studies have suggested that the relationship between carbon isotopes and growth might not be a simple one (Ferrio et al. 2003; Peñuelas et al. 2008; Jansen et al. 2013; Hentschel et al. 2016; Shestakova et al. 2017), but to our knowledge none had explored the relationship across a broad enough range of species and environmental conditions to draw this conclusion robustly. The relatively small declines in growth we observed in response to drought suggest that most European tree species are - on average - able to maintain growth under conditions of low soil water availability.. This is not to say that water availability is ...
Squalene epoxidase enzymes catalyse the conversion of squalene into 2,3-oxidosqualene, the precursor of cyclic triterpenoids. Here we report that the Arabidopsis drought hypersensitive/squalene epoxidase 1-5 (dry2/sqe1-5) mutant, identified by its extreme hypersensitivity to drought stress, has altered stomatal responses and root defects because of a point mutation in the SQUALENE EPOXIDASE 1 (SQE1) gene. GC-MS analysis indicated that the dry2/sqe1-5 mutant has altered sterol composition in roots but wild-type sterol composition in shoots, indicating an essential role for SQE1 in root sterol biosynthesis. Importantly, the stomatal and root defects of the dry2/sqe1-5 mutant are associated with altered production of reactive oxygen species. As RHD2 NADPH oxidase is de-localized in dry2/sqe1-5 root hairs, we propose that sterols play an essential role in the localization of NADPH oxidases required for regulation of reactive oxygen species, stomatal responses and drought tolerance.
Recent drought events have caused substantial yield loses in Australia and therefore genetic improvement of drought tolerance has become a high priority in wheat breeding programs. As some Western Australian wheat varieties have shown high levels of water soluble carbohydrates (WSC) at anthesis, understanding the role of WSC in terminal drought tolerance has been the primary focus of our recent drought research. The objectives of this study were to evaluate the impact of stem WSC at anthesis on drought tolerance during grain filling and map the genes responsible for the accumulation of stem carbohydrates and grain yield. Two doubled-haploid (DH) populations, Westonia/Kauz (W/K) and Westonia*2/Janz (W/J), were studied in the field environment under conditions where water supply was manipulated. The analysis of grain yield data showed 3 to 5-fold variation in under drought conditions. Transgressive segregation was observed for grain yield in both populations. Stem carbohydrate concentrations at ...
Safflower (Carthamus tinctorius L.) is a drought-tolerant species that grows in arid and semi-arid environments exposing to long periods of water deficit stress. Structure and functions of the plant organs including leaf anatomy are affected by drought stress. The objective of this study was to evaluate the effects of drought stress on some leaf anatomical traits including leaf thickness, upper and lower epidermal thickness, xylem width, metaxylem diameter, and vascular bundle width and their relationship with grain yield using 20 safflower genotypes under field conditions. A randomized complete block design was used in each of the non-stress and drought stress field conditions. Analysis of variance showed that drought stress significantly reduced all variables measured except vascular bundle width. The results also revealed the positive and significant correlations between grain yield with leaf thickness (r = 0.53**) and xylem width (r = 0.51**) under drought stress conditions. Due to this ...
Truncated] One of the consequences of climate change is a change in rainfall distribution with more frequent and unpredictable droughts in some regions. Drought threatens supplies of oil produced from oilseed rape/canola (Brassica napus), while at the same time, international demand for oilseeds is growing at an unprecedented rate. B. rapa, one of the diploid progenitor species of the genetically-narrow and relatively recent allopolyploid B. napus, exhibits greater genetic variation and wider natural distribution than B. napus, and therefore is a promising source of drought tolerance alleles for canola breeders. This thesis aims to develop screening methods for drought tolerance in B. rapa during the reproductive phase, and to identify expressed drought tolerance genes that may be transferred to B. napus. An integrated approach was developed to meet this goal, from assessment of genetic diversity, physiological evaluation of drought tolerance to transcriptome analysis of drought-tolerant and ...
Drought is a major abiotic constraint to common bean (Phaseolus vulgaris L.) production globally. It results into yield losses of over 60% depending on severity, time and duration of occurrence. In the face of climate change and variability, droughts have become frequent and more severe in Kenya leading to reduced bean production. It is therefore important to curb further decline in dry bean production and enhance food security by developing drought tolerant varieties of dry bean. Of the two major dry bean gene pools, the small seeded Mesoamerican beans are considered to be more drought tolerant than the large seeded Andean beans. However, little has been done to develop drought tolerant bean varieties and to understand the mechanisms of drought tolerance in Kenya and East Africa in general. The objective of this study was to identify physiological and phenological traits associated with enhanced drought tolerance in Mesoamerican dry bean genotypes. Eighty-five small and medium seeded bean lines ...
Arabidopsis thaliana acyl-CoA-binding protein 2 (ACBP2) is a stress-responsive protein that is also important in embryogenesis. Here, we assign a role for ACBP2 in abscisic acid (ABA) signalling during seed germination, seedling development and the drought response. ACBP2 was induced by ABA and drought, and transgenic Arabidopsis overexpressing ACBP2 (ACBP2-OXs) showed increased sensitivity to ABA treatment during germination and seedling development. ACBP2-OXs also displayed improved drought tolerance and ABA-mediated reactive oxygen species (ROS) production in guard cells, thereby promoting stomatal closure, reducing water loss and enhancing drought tolerance. In contrast, acbp2 mutant plants showed decreased sensitivity to ABA in root development and were more sensitive to drought stress. RNA analyses revealed that ACBP2 overexpression up-regulated the expression of Respiratory Burst Oxidase Homolog D (AtrbohD) and AtrbohF, two NAD(P)H oxidases essential for ABA-mediated ROS production, ...
Nonnative plants alter the composition of native plant communities, with concomitant effects on arthropods. However, plant invasions may not be the only disturbance affecting native communities, and multiple disturbances can have compounding effects. We assessed the effects of invasion and drought on plant and arthropod communities by comparing grasslands dominated by nonnative Old World bluestem grasses (OWBs, Dichanthium annulatum) to grasslands dominated by native plants during a period of decreasing drought severity (2011â€2013). Native plant communities had more species of plants and arthropods (/m2) than areas dominated by OWBs during extreme drought, but richness was comparable as drought severity decreased. Abundance of arthropods was greater in native plant communities than in OWB communities during extreme drought, but OWB communities had more arthropods during moderate and non-drought conditions. We observed a shift in the arthropod community from one dominated by detritivores to ...
Drought is a major environmental stress that can have severe impacts on plant productivity and survival. Understanding molecular mechanisms of drought responses is crucial in order to breed for drought adapted plant cultivars. The aim of the present study was to investigate phenotypic and transcriptional drought responses in two willow genotypes (520 and 592) originating from an experimental cross between S. viminalis × (S. viminalis × S. schwerinii). Willows are woody perennials in the Salicaceae plant family that are grown as bioenergy crops worldwide. An experiment was conducted where plants were exposed to drought and different eco-physiological parameters were assessed. RNA-seq data was furthermore generated with the Illumina technology from root tips and leaves from plants grown in drought and well-watered (WW) conditions. The RNA-seq data was assembled de novo with the Trinity assembler to create a reference gene set to which the reads were mapped in order to obtain differentially expressed
Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/belowground system comprising a generalist and a specialist aphid species (foliar herbivores), their parasitoids, and a dipteran species (root herbivore).We tested the hypotheses that: (1) high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2) drought stress and root herbivory change the profile of volatile organic chemicals (VOCs) emitted by the host plant; (3) parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference), plant volatile emissions, parasitism success (performance), and the effect of drought on root herbivory. ...
Bioenergy is an important renewable energy option worldwide, but the industry is susceptible to a myriad of risks including biomass supply, of which drought plays a role. Crops yields decrease during drought, increasing year-to-year risk for the agricultural industry. For the renewable energy industry, in particular, the effect of drought on crops is substantial and complex. This chapter discusses the current state of knowledge regarding how drought affects biomass destined for renewable energy as it relates to dry biomass yields and chemistry, the latter of which heavily impacts cost of production and final product yields. Advanced supply systems are one option for reducing biomass supply risk. These systems lead to higher, less variable crop yields during uncontrollable events like drought; however, the quality of material supplied in a drought year may still vary as drought impacts plant chemistry. This chapter provides analysis for chemical composition of four bioenergy crops observing that both
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Drinking water deficit is a serious environmental factor limiting the growth and productivity of plants worldwide. activating downstream target genes related to drought resistance, such as (Niu and negatively regulate WUE and drought tolerance in (Yoo family and regulates a series of related gene expressions (Testa family. Several and members in ((family members in plants have been found to function in drought stress. Li (2008) found that the plants overexpressing display reduced stomatal aperture and leaf water loss and significantly promote drought resistance and is regulated transcriptionally by abscisic acid (ABA) and posttranscriptionally by confers improved performance in with higher water potential and photosynthesis rates under drought treatments. Transgenic maize plants with transcription factors and WUE. This study identified a poplar drought-responsive family member from the fast-growing black cottonwood with high WUE, which conferred drought tolerance and improved plant WUE under ...
Drinking water deficit is a serious environmental factor limiting the growth and productivity of plants worldwide. activating downstream target genes related to drought resistance, such as (Niu and negatively regulate WUE and drought tolerance in (Yoo family and regulates a series of related gene expressions (Testa family. Several and members in ((family members in plants have been found to function in drought stress. Li (2008) found that the plants overexpressing display reduced stomatal aperture and leaf water loss and significantly promote drought resistance and is regulated transcriptionally by abscisic acid (ABA) and posttranscriptionally by confers improved performance in with higher water potential and photosynthesis rates under drought treatments. Transgenic maize plants with transcription factors and WUE. This study identified a poplar drought-responsive family member from the fast-growing black cottonwood with high WUE, which conferred drought tolerance and improved plant WUE under ...
INVESTIGATION OF MORPHOLOGICAL AND PHYTOCHEMICAL CHANGES AND TOLERANCE THRESHOLD OF CHAMOMILE UNDER DROUGHT STRESS CONDITIONS, Parisa Sharifi, Mahdi Seyedsalehi, Ombretta Paladino,
The physiological data suggest that ABA treatment enhanced drought tolerance in both turfgrass species but was more effective for kentucky bluegrass. Similar effects have also been reported by McCann and Huang (2008) who found increased TQ scores, growth rate, and leaf photochemical efficiency for ABA-treated creeping bentgrass and kentucky bluegrass compared with untreated controls. The positive effects of ABA on drought tolerance of creeping bentgrass and kentucky bluegrass have been attributed to the induction of stomatal closure lessening water loss and also with enhanced osmotic adjustment maintaining cellular turgidity (McCann and Huang, 2008; Wang et al., 2003). In the present study, foliar ABA significantly reduced EL in kentucky bluegrass plants but did not have significant effects on RWC in either grass species. The application of ABA was found to reduce membrane damages induced by drought stress in other plant species (Rajasekaran and Blake, 1999). Wang et al. (2003) also observed ...
Stay-green is an integrated drought adaptation trait characterized by a distinct green leaf phenotype during grain filling under terminal drought. We used sorghum (Sorghum bicolor), a repository of drought adaptation mechanisms, to elucidate the physiological and genetic mechanisms underpinning stay-green. * Near-isogenic sorghum lines (cv RTx7000) were characterized in a series of field and managed-environment trials (seven experiments and 14 environments) to determine the influence of four individual stay-green (Stg1-4) quantitative trait loci (QTLs) on canopy development, water use and grain yield under post-anthesis drought. * The Stg QTL decreased tillering and the size of upper leaves, which reduced canopy size at anthesis. This reduction in transpirational leaf area conserved soil water before anthesis for use during grain filling. Increased water uptake during grain filling of Stg near-isogenic lines (NILs) relative to RTx7000 resulted in higher post-anthesis biomass production, grain ...
Article Drought stress responses and recovery of Texas x Kentucky hybrids and Kentucky bluegrass genotypes in temperate climate conditions. Turf quality (TQ) decline due to drought is a major concern in cool-season turfgrass management. The study was...
Drought stress is one of the major abiotic factors affecting crop growth and limiting production worldwide. Cotton genotypes vary in drought tolerance, and the effects of drought stress on the anatomy and physiology of cotton leaves and roots have been reported. However, information on physiological and metabolic processes of leaves and flowers of modern cotton cultivars under water-deficit stress during reproductive development is not well elucidated. It was hypothesized that water-deficit stress during squaring and flowering stages would impair stomatal conductance and photosynthetic efficiency of leaves, which consequently would result in osmotic adjustment through accumulation of compatible solutes, increased activity of enzymes, and perturbation of carbohydrates metabolism in leaves and flowers of cotton plants, and differences in drought tolerance among the genotypes would exist. Therefore, field and growth room experiments were conducted to evaluate the effects of water-deficit stress during
Drought tolerance was evaluated in twelve cultivars of three ornamental Tagetes species (T. patula, T. tenuifolia and T. erecta). A stress treatment was performed by completely stopping watering of plants maintained in controlled greenhouse conditions. After three weeks, several plant growth parameters (stem length (SL), fresh weight (FW) and water content (WC)), photosynthetic pigments (chlorophylls and carotenoids (Car)), osmolytes (proline (Pro), glycine betaine (GB) and total soluble sugars (TSS)), an oxidative stress maker (malondialdehyde (MDA)) and antioxidants (total phenolic compounds (TPC) and total flavonoids (TF)) were measured. Considerable differences in the evaluated traits were found among the control and drought-stressed plants. Drought stress generally caused a marked reduction in plant growth and carotenoid pigments, and an increase in soluble solutes and oxidative stress. For most cultivars, proline levels in stressed plants increased between 30 and 70-fold compared to the
Drought is one of the major abiotic stresses that affect rice production in rainfed areas. Recent trends in climate change have predicted a further increase in drought intensity, making the development of new drought-tolerant rice cultivars critical to sustain rice production in this ecosystem. The use of grain yield as a selection criterion at the International Rice Research Institute (IRRI), through proper population development and precise phenotyping techniques, has allowed the development of several high-yielding rice cultivars that have been released in major rainfed rice-growing areas. This strategy has also allowed the identification of several major quantitative trait loci (QTLs) that show large effects under drought across environments and genetic backgrounds. These QTLs are being pyramided together to develop drought-tolerant versions of popular drought-susceptible varieties. The near-isogenic lines (NILs) developed can replace the popular, high-yielding but drought-susceptible varieties in
TY - JOUR. T1 - Why life history information matters. T2 - Drought refuges and macroinvertebrate persistence in non-perennial streams subject to a drier climate. AU - Robson, Belinda J. AU - Chester, E T. AU - Austin, Chris. PY - 2011/7/25. Y1 - 2011/7/25. N2 - In some arid, semi-arid or Mediterranean climate regions, increased water extraction combined with climate change will prolong periods of drought in non-perennial streams, but the effects on macroinvertebrate populations are poorly understood. Drought refuges allow species to survive drying but their use depends on species traits, and refuge availability depends on landscape structure. This review evaluates the utility of existing ecological concepts for predicting the role of drought refuges for sustaining biodiversity in non-perennial streams. We also suggest traits that may determine invertebrate species resistance or resilience to prolonged drying. Parts of the likely responses by populations to increased stream drying are described ...
The current drought is most notably taking its toll on cattle and milk production. There are regions in Colombia that have reported a 50% reduction in milk production, according to El Espectador.. MORE: Cattle ranchers ask Colombias government to combat effects of drought. A farmer affected by the drought explained, It is better to sell them because [the animals] are too skinny. We arent the animals owners; the owners are the people that come and offer a certain value for them, and we have to except what we get because that is all there is, according to El Espectador newspaper.. According to El Tiempo, the northern tip of Colombia, in the state of La Guajira, has not seen rain in two years. The town of Riohacha had to suspend aqueduct services because the water was coming down from the Sierra Nevada mountains with too much sediment due of the lack of rain in the region.. MORE: Drought in northern Colombia at crisis levels. The NGRD has been accompanying communities in La Guajira, providing ...
a. Amaranth. Two pathways are evident in the maintenance of turgor in amaranth: the modulation of LWP and RWC. Restoration and repair upon rehydration are critical components of desiccation tolerance, and recovery of leaf area. The lower RWC and LWP values coincide with lower photosynthetic activity and rate of decrease in leaf area during drought stress. Furthermore, the ability of the membrane to retain and selectively transport cellular solutes gives an indication of the cellular membrane function. CMS assay indicates excessive leakage of cellular electrolytes and is usable as an indication of cellular membrane injury. TTC reduction assay measures the dehydrogenase activity of the intact cell. Proline accumulation screening seems to be highly useful for determining genotype variation in drought tolerance in amaranth. This is possible since differences in the onset of proline accumulation, as well as amount of proline accumulated as a result of severe water deficit, were observed in the ...
Read Integration of transcriptomic and metabolic data reveals hub transcription factors involved in drought stress response in sunflower (Helianthus annuus L.), Plant Molecular Biology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
In the present work we investigated the potential beneficial effects of the exogenous application of S-methylmethionine (SMM) that plays an important role in the plants sulphur metabolism and contributes to the production of certain defence compounds. The possible beneficial effects were challenged against Maize dwarf mosaic virus infection and drought stress. We studied the expression changes of GF14-6 and SAMS during viral infection and DREB2A and DBP2 during drought stress. The product of GF14-6 recognise the viral coat protein and contributes to RNA-silencing, while the product of SAMS plays a central role in the plant sulphur metabolism and contributes to the production of several defence compounds. The products of DREB2A and DBP2 contribute to better plant defence against drought stress and increase the efficiency of water uptake. According to our results, SMM pretreatment has a considerable change on the investigated genes expression. It significantly decreases the gene expression of ...
Information regarding the different downstream target genes of WRKY TFs that regulate abiotic stress-induced responses is limited. Advances have, however, been made in a dehydration tolerance signaling pathway in the resurrection plant Boea hygrometrica (Wang et al. 2009). An important downstream target gene, Galactinol synthase 1 (BhGolS1), which plays a role in drought and cold tolerance (Teruaki et al. 2002) was found to be dehydration and ABA inducible. The BhGolS1 promoter contains four W boxes and chromatin immunoprecipitation showed that it is bound in vivo by the early dehydration and ABA-inducible BhWRKY1 TF (Wang et al. 2009). These observations provide direct insights into the role of a dehydration-inducible WRKY TF that interacts with a downstream target gene that plays an important role in drought responses. Recently, convincing evidence has been presented to show that AtWRKY8 functions antagonistically with its interacting partner VQ9 to modulate salinity tolerance (Hu et al. ...
Agricultural drought is a temporary condition that occurs for a short period of time due to deficient precipitation on vegetation and prolonged deficiency of soil moisture. This is the result of imbalance between soil moisture and evapotranspiration. The effectiveness of horticultural practices in conserving of soil moisture and reducing of evapotranspiration area has generally been found to be higher under drought conditions. The aim of this research was to find the best horticultural practices for reducing agricultural drought damages in the rainfed fig (Ficus carica Sabz) orchards. The experiment consisted of 7 treatments and 5 replications and continued for three years. The best treatments with the best effect on economic and technical characteristics were selected and recommended using the technique for order preference by similarity to ideal solution (TOPSIS) method. Results showed if we considered yield of tree as the only criterion for selecting the best treatment, the mechanical weeds ...
Understanding the ways that plants can tolerate drought and salinity is necessary to develop plants that can grow on potential agricultural lands that are otherwise non-productive. The expression of a broad spectrum of genes is thought to be regulated by exposure to environmental salinity and water-deficit stress, the major stresses of plants in arid regions. Plant responses to salt and to drought stress have much in common. Both of these stresses reduce the ability of the plants to take up water and this quickly causes reduction in plant growth rate. The overall goal of this project was to identify proteins involved in response to drought and salinity stress in tomato. Combined proteomic approaches, two dimensional gel electrophoresis (2 DE) and liquid chromatography mass spectrometry (LC-MS/MS), revealed the plasticity of gene expression by protein analysis during environmental stress. Tomato plants were exposed to various concentrations of salt (sodium chloride) and polyethylene glycol ...
Common bean is an important legume crop with only a moderate number of short expressed sequence tags (ESTs) made with traditional methods. The goal of this research was to use full-length cDNA technology to develop ESTs that would overlap with the beginning of open reading frames and therefore be useful for gene annotation of genomic sequences. The library was also constructed to represent genes expressed under drought, low soil phosphorus and high soil aluminum toxicity. We also undertook comparisons of the full-length cDNA library to two previous non-full clone EST sets for common bean. Two full-length cDNA libraries were constructed: one for the drought tolerant Mesoamerican genotype BAT477 and the other one for the acid-soil tolerant Andean genotype G19833 which has been selected for genome sequencing. Plants were grown in three soil types using deep rooting cylinders subjected to drought and non-drought stress and tissues were collected from both roots and above ground parts. A total of 20,000
Grassland management can modify soil microbial carbon (C)and nitrogen (N)cycling, affecting the resistance to extreme weather events, which are predicted to increase in frequency and magnitude in the near future. However, effects of grassland management on microbial C and N cycling and their responses to extreme weather events, such as droughts and heatwaves, have rarely been tested in a combined approach. We therefore investigated whether grassland management affects microbial C and N cycling responses to drought and temperature manipulation. We collected soils from in situ drought experiments conducted in an extensively managed and an abandoned mountain grassland and incubated them at two temperature levels. We measured microbial respiration and substrate incorporation, as well as gross rates of organic and inorganic N cycling to estimate microbial C and N use efficiencies (CUE and NUE). The managed grassland was characterized by lower microbial biomass, lower fungi to bacteria ratio, and ...
The 2016-2017 drought has brought Somalia to the brink of famine. An estimated 6.7 million - half the population - are acutely food insecure and in need of humanitarian assistance. Somalia has seen around 7 percent of its population (760,000 people) newly displaced, and the scarcity of safe drinking water has led to outbreaks of Acute Watery Diarrhea /Cholera resulting in around 800 fatalities. The drought has caused large-scale crop failures and livestock deaths, impacting livelihoods and food supply. This shock is taking place in an existing fragile conflict environment with high levels of poverty, widespread water shortages, food insecurity, displacement and deep communal tensions. The Federal Government of Somalia (FGS), through the Ministry of Planning, Investment and Economic Development and the Ministry of Humanitarian and Disaster Management, has requested support from the WB/GFDRR, together with the EU and the UNDP, to undertake a comprehensive Drought Impact & Needs Assessment (DINA). ...
Its as you would expect, Fitzpatrick says. Just as there are more similarities between a humans gut microbiome and an apes than between a humans and a mouses, the closer the relationship between plant species, the more similar their root microbiomes. Its important to document as a way to better understand the evolutionary processes shaping the plant root microbiome.. In addition to deepening our basic biological understanding of plant evolution and development, the research offers further avenues for study, including how and why some plants recruit bacteria that impact drought resistance while others dont.. If plants were able to enrich their root microbiomes with a particular group of bacteria, the Actinobacteria, they grew much better in drought conditions, says Fitzpatrick. All of our plants had access to this group of bacteria, but they also needed to have the ability to recruit it from the soil.. In another finding that is consistent with the practice of crop rotation, ...
EN. Brussels, 18.7.2007. COM(2007) 414 final. COMMUNICATION FROM THE COMMISSION. TO THE EUROPEAN PARLIAMENT AND THE COUNCIL. Addressing the challenge of water scarcity and droughts in the European Union. {SEC(2007) 993}. {SEC(2007) 996}. COMMUNICATION FROM THE COMMISSION. TO THE EUROPEAN PARLIAMENT AND THE COUNCIL. Addressing the challenge of water scarcity and droughts in the European Union (Text with EEA relevance). Access to good quality water in sufficient quantity is fundamental to the daily lives of every human being and to most economic activities. But water scarcity and droughts have now emerged as a major challenge - and climate change is expected to make matters worse. This is a worldwide problem, and the European Union is not spared.. Over the past thirty years, droughts have dramatically increased in number and intensity in the EU. The number of areas and people affected by droughts went up by almost 20% between 1976 and 2006. One of the most widespread droughts occurred in 2003 when ...
Drought stress is considered one of the most devastating abiotic stress factors that limit crop productivity for modern agriculture worldwide. There is a large range of physiological and biochemical responses induced by drought stress. The responses range from physiological and biochemical to regulation at transcription and posttranscriptional levels. Post-transcription, the products encoded by eukaryotic genes must undergo a series of modifications to become a mature mRNA. Polyadenylation is an important one in terms of regulation. Polyadenylation impacts gene expression through determining the coding and regulation potential of the mRNA, especially when different mRNAs from the same gene may be polyadenylated at more than one position. This alternative polyadenylation (APA) has numerous potential effects on gene regulation and function. I have studied the impact of drought stress on APA, testing the hypothesis that drought stress may give rise to changes in the usage of poly(A) sites generating
If it werent for the seriousness of the matter, I would feel a delicious sense of schadenfreude about THIS:If the latest news reports are any indication, the droughts that have wracked a large portion of the contiguous United States continued piling on the damage in Texas and Oklahoma through 2012. The effects will reverberate for years and global warming will make such brutal droughts (or worse) the regions normal climateif we keep listening to the deniers call to inaction.Its a particular bitter irony, given that the political and media cultures of both states, with Sen. James Inhofe ... Read more
Causing crop damage that has been exasperated by drought conditions, soybean aphids moved into area fields earlier than experts expected and their numbers have been higher than anyone anticipated, said Dave Schwartz, Meeker County extension educator.. Soybean aphids - insects relatively new to Minnesota - found their way into area fields and by the end of July and their populations exploded in area fields and in fields in surrounding counties, said Schwartz. The insects are native to Asia and it is believed that they found their way into this country along with Asian soybeans in 2000. Because they are still a relatively new nusance in this country, not a lot is known yet about the insects, said Schwartz. Soybean aphids attach themselves to healthy soybean plants and suck fluids from it, essentially dehydrating the plant leaving behind a sticky residue. During the current stage of soybean development, when pods are forming and beans are developing, plants respond to the loss of nutrients by ...
Read Physiological changes in them in post-stress emerging Ctenanthe setosa plants under drought conditions, Russian Journal of Plant Physiology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
The present study evaluates the effects of plant growth hormones (PGR), salicylic acid (SA), abscisic acid (ABA) and plant growth promoting rhizobacteria (PGPRs) Rhizobium pisi (DSM 30132 strain) applied alone and in combination, on pea (Pisum sativum L.) cv. Florida plants under well-watered and drought stressed conditions. Prior to sowing seeds were soaked for 5h in broth culture (108 cfu/ml) of Rhizobium pisi and SA /ABA. Seeds were soaked for 6h in distilled water, ABA, SA solutions. Plants were subjected to drought stress on 21 days old seedlings by withholding the supply of water at two different time points; for 4d (TP1) and for 8d (TP2). Rhizosphere soil of abscisic acid treated plants exhibited higher retention of soil moisture at TP1. Abscisic acid decreased the fresh and dry weight of plants under unstressed condition but increased the fresh weight as well as relative water content under drought stress. The response of Rhizobium and SA were at par. Rhizobium and SA ameliorated the ...
Global warming and extreme temperatures caused by climate change lead to stress conditions that interfere with plant growth and crop productivity. Plants have been constantly evolving defense mechanisms to overcome these stress conditions, such as high temperatures, drought, high salinity, and cold. Osmotic stress, caused by water deficits, also affects plant growth and causes reduced crop yields. Among osmotic stresses, drought stress is closely related to stomatal adjustment and is one of the major abiotic stresses (Golldack et al., 2014; Lee and Luan, 2012). When plants are exposed to drought conditions, closure of stomata in response to abscisic acid (ABA) occurs to minimize water loss (Golldack et al., 2014; Lee and Luan, 2012).. ABA is a key hormone in plant responses to abiotic stress, especially drought stress (Osakabe et al., 2014), as it modulates several stress-related genes, including protein kinases, phosphatases, transcription factors, and ion channels involved in osmotic ...
Overexpression of AtEDT1 Gene Confers Drought Tolerance in Alfalfa: Alfalfa (Medicago sativa L.) is an important legume forage crop with great economic value. However, the growth of alfalfa is seriously affected by an ...
We are also announcing today, a step, as a contribution to that and one that we hope will lead the rest of the international community, she added.. Smith also announced her governments plan to deploy a disaster assistance team to Ethiopia.. The Administrator said that it was imperative for the international community not to only respond to human suffering, but to also strive to promptly respond to the mitigation of worse situations.. We are moving earlier in this case because we have found that there is real alignment between donors, NGOs, the governments, and UN agencies.. We believe that if we move very, very, very quickly, we can avert the worst impacts of this drought, she said.. According to her, the UN estimates that what is needed urgently over the next three months to addressing the situation is $268 million. ...
The goal of the City of Asheville Water Resources Department is to operate its water production facilities in the most efficient manner possible. This includes ensuring optimal operation of the water production and distribution systems, including the production of high quality water, providing timely maintenance and repair of the water infrastructure, and promoting efficient and conservative use of regional water resources.. Our primary water source is a 6 billion gallon lake located in Black Mountain, North Carolina - the North Fork Reservoir. This lake is located within a 22,000 acre protected watershed. Along with the Bee Tree and the Mills River Water Treatment Plants, these facilities provide water to more than 125,000 area residents.. The City of Asheville uses a computerized drought management model to help predict future lake levels and drought conditions. This model takes into account current water levels, forecasted precipitation, past lake levels and recent rainfall to predict future ...
Total Federal Funds: $235,148 Total Non-Federal Funds: $242,866. Principal Investigators: Vijay Singh, Ashok Mishra. Abstract: Droughts in the United States result in an estimated average annual damage of $6 to 8 billion. The estimated loss from the 1988 drought was $40 billion and the estimated loss for the state of Texas alone from the 1996 drought was $6 billion. Like other western states, Texas is a water deficient state and is highly vulnerable to droughts, and its vulnerability is being compounded by rapidly growing population. According to the Water Plan developed by Texas Water Development Board, water shortages during droughts could cost businesses and workers in the state about $9.1 billion by 2010 and $98.4 billion by 2060 and about 85 percent of the states projected population would not have enough water by 2060 (in drought conditions), if an additional 8.8 million acre-feet of water supplies are not developed. Further complicating the Texas water shortage is climate change, which is ...