The phloem plays a crucial role in assimilate and nutrient transport, pathogen response, and plant growth and development. Yet, few species have yielded pure phloem exudate and, if proteins need to be analysed, those species may not have sequenced genomes, making identification difficult. The enrichment of Arabidopsis thaliana phloem exudate in amounts large enough to allow for metabolite and protein analysis is described. Using this method, it was possible to identify 65 proteins present in the Arabidopsis phloem exudate. The majority of these proteins could be grouped by response to pathogens, stress, or hormones, carbon metabolism, protein interaction, modification, and turnover, and transcription factors. It was also possible to detect 11 proteins that play a role in lipid/fatty acid metabolism (aspartic protease, putative 3-β-hydroxysteroid dehydrogenase, UDP-sulphoquinovose synthase/SQD1, lipase, PIG-P-like protein: phosphatidylinositol-N-acetylglucosaminyltransferase), storage (glycine-rich
Vascular phloem loading has long been recognized as an essential step in the establishment of a systemic virus infection. Yet little is known about this process and the mechanisms that control it. In this study, an interaction between the replication protein of Tobacco mosaic virus (TMV) and phloem specific auxin/indole acetic acid (Aux/IAA) transcriptional regulators was found to modulate virus phloem loading. Promoter expression studies show TMV 126/183 kDa interacting Aux/IAAs predominantly express and accumulate within the nuclei of phloem companion cells (CC). Furthermore, CC Aux/IAA nuclear localization is disrupted upon infection with an interacting virus but not during infection with a non-interacting virus. In situ analysis of virus spread shows the inability of TMV variants to disrupt Aux/IAA CC nuclear localization correlates with a reduced ability to load into the vascular tissue. Subsequent systemic movement assays also demonstrate that a virus capable of disrupting Aux/IAA ...
(a) Delineating the transport path Phloem loading is used variously to describe transport events outside, and inside, phloem tissues of leaves. The broader general application is adopted here - that is, phloem loading describes photoassimilate transport from the cytoplasm of photosynthetic mesophyll cells to se-cc complexes of leaf phloem.
The invention discloses a kind of high-efficiency high-quality beans screening installation, including feed pipe, casing, inclined guide plate, sieve plate, vibrator, spring, expansion link, wet concentration case, camera, winnowing machine and drying baker, described casing top is provided with feed pipe, wall box is provided with timer, cabinet wall is provided with winnowing machine, sieve plate is provided with casing, sieve plate is provided with vibrator, sieve plate underrun spring is connected with expansion link top, casing bottom is connected by the first transfer tube with wet concentration case, the port of export contacts connection with the first transfer tube, filter plate is provided with wet concentration bottom end, rotating shaft is provided with wet concentration case, stirring vane is installed in rotating shaft, rotating shaft is connected with external motor, it is connected in the middle part of wet concentration case by the second transfer tube with drying baker, provided
This funny-looking, little offset patch/circle/whatever is called the madreporite or sieve plate. As you can see, it is composed of a bunch of grooves which are each, in turn part of a porous calcium carbonate plate covered with pores. The word madreporite is named for its resemblance to a genus of hard coral called Madrepora whose surface is covered by numerous small openings. As well see there are numerous small openings (i.e., pores) that cover the surface of the madreporite as well ...
A major question in plant biology concerns the specification and functional differentiation of cell types. This is in the context of constraints imposed by networks of cell walls that both adhere cells and contribute to the form and function of developing organs. Here, we report the identification of a glycan epitope that is specific to phloem sieve element cell walls in several systems. A monoclonal antibody, designated LM26, binds to the cell wall of phloem sieve elements in stems of Arabidopsis (Arabidopsis thaliana), Miscanthus x giganteus, and notably sugar beet (Beta vulgaris) roots where phloem identification is an important factor for the study of phloem unloading of Suc. Using microarrays of synthetic oligosaccharides, the LM26 epitope has been identified as a β-1,6-galactosyl substitution of β-1,4-galactan requiring more than three backbone residues for optimized recognition. This branched galactan structure has previously been identified in garlic (Allium sativum) bulbs in which the ...
Since sieve-tube members do not contain either a nucleus or ribosomes, they require the assistance of companion cells for the functioning. Moreover, since the salivary proteins contain calcium-binding domains (Will et al., 2007), it was suggested that aphid saliva can act as a chemical calcium scavenger to prevent an increase in calcium concentration and hence the sieve tube sealing response. A long-distance translocatable phloem protein (CsPP2) from cucumber has a potential double-spaced RNA-binding motif and forms an RNP complex with HSVd (Gómez and Pallás, 2004). The cleavage function was especially upregulated by ATP, suggestive of ATP-mediated conformational changes required to cleave the nonanucleotides. Subsequently, Rep closes the nascent 3′ end of the DNA with the previously generated 5′ end. Each STM is a living cell. Sieve tubes are separated into sieve tube members, commonly referred to as sieve elements, by thickened end walls, termed sieve plates, pierced by sieve pores. ...
The fate of imported photoassimilates depends on sink cell function. In broad terms, imported photoassimilates are primarily used to provide carbon skeletons or signals for growth or storage. Some photoassimilates provide energy for maintenance. Relative flows of photoassimilates to these fates change during cell development and sometimes over shorter time scales depending upon a plants physiological state.
Calcium-dependent protein kinases (CDPKs) constitute a unique family of enzymes in plants that are characterized by a C-terminal calmodulin (CaM)-like domain. Through protein kinase assays, we have examined the levels of cucumber calcium-dependent kinase $(C_SCDPK)$ activity in various organs of cucumber seedlings and plants. The activity of $C_SCDPK$ was highest in cucumber plant leaves followed by seedling roots and hypocotyls; however, cucumber plant flowers, seedling cotyledons, and hooks had levels that were barely detectable. The $C_SCDPKs$ were immunolocalized using polyclonal antibodies that are highly specific against a part of the kinase domain of a calcium-dependent protein kinase $(C_SCDPKS)$ in the phloem sieve elements (SEs) in various organs of cucumber. In addition, this study indicates the presence of CsCDPKs in organelle-like bodies associated with the plasma membrane of sieve elements in mature stems and roots as well as in the storage bodies of immature seeds. These findings ...
Sieve elements are terminally differentiated cells that undergo exceptional cytoplasmic reorganization to become the functional living conductive cells of the phloem. During differentiation, the lumen of sieve elements becomes a low-resistance pathway for mass flow by selective degradation of the nucleus, ribosomes, dictyosomes, and vacuoles, as well as undergoing changes in the endoplasmic reticulum forming the uniquely structured sieve element reticulum. The junction between the sieve element reticulum and the sieve element plasma membrane (SEPM) ultimately forms a tightly coupled parietal membrane complex that includes P protein, mitochondria, and plastids held together by ultrastructurally defined clamp-like structures in mature sieve elements (Sjölund and Shih, 1983; Ehlers et al., 2000). High-resolution electron microscopy detected minute actin and profilin-like structures that could anchor the organelles in a parietal position (Ehlers et al., 2000). The intact plasma membrane becomes ...
The answer to this question is: Phloem fibres provide support to the phloem tissue. Access a diverse Question Bank and ask You Own Doubt Now!
Phloem is an equally important plant tissue as it also is part of the plumbing system of a plant. Primarily, phloem carries dissolved food substances throughout the plant. This conduction system is composed of sieve-tube member and companion cells, that are without secondary walls. The parent cells of the vascular cambium produce both xylem and phloem. This usually also includes fibers, parenchyma and ray cells. Sieve tubes are formed from sieve-tube members laid end to end. The end walls, unlike vessel members in xylem, do not have openings. The end walls, however, are full of small pores where cytoplasm extends from cell to cell. These porous connections are called sieve plates. In spite of the fact that their cytoplasm is actively involved in the conduction of food materials, sieve-tube members do not have nuclei at maturity. It is the companion cells that are nestled between sieve-tube members that function in some manner bringing about the conduction of food. Sieve-tube members that are ...
Aphids are serious pest on crops. By probing with their stylets, they interact with the plant, they vector viruses and when they reach the phloem they start a continuous ingestion. Many plant resistances to aphids have been identified, several have been deployed. However, some resistances breaking down have been observed. In the melon, a gene that confers resistance to aphids has been deployed in some melon-producing areas, and aphid colony development on Vat-carrying plants has been observed in certain agrosystems. The Vat gene is a NBS-LRR gene that confers resistance to the aphid species Aphis gossypii and exhibits the unusual characteristic of also conferring resistance to non-persistently transmitted viruses when they are inoculated by the aphid. Thus, we characterized patterns of resistance to aphid and virus using the aphid diversity and we investigated the mechanisms by which aphids and viruses may adapt to the Vat gene. Using a Vat-transgenic line built in a susceptible background, we described
With a 10% fuel-air ratio increase, relate a ratio showing a decrease in mass flow from a 10% increase in the mass flow rate to the ratio of decreasing Mach number. The increase in pressure ratio contributes to increasing the mass flow rate, but not as much as the decrease in Mach number decreases the mass flow rate. All other variables are constant between the two cases.. ...
The Caltech Tree Machine has an ensemble architecture, Processors are interconnected into a binary tree. Each node executes its own code. No two nodes need to execute identical code. Nodes are synchronized by messages between adjacent nodes. Since the number of nodes is intended to be large, in the order of thousands, great care needs to be exercised in devising loading strategies to make the loading time as short as possible. A constraint is also imposed by the very limited storage associated with a processor. Nodes are assigned a type that identifies the code it shall execute. Nodes of the same type execute identical code. Tree Machine programs are frequently very regular. By exploiting this regularity, compact descriptions of the types of all nodes in the tree can be created. The limited storage of a node, and the desire to only use local information in the expansion of the compacted description implies constraints on the compression/decompression algorithms. A loading time proportional to ...
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Biology Assignment Help, Types of transport process in sieve tubes, Types of Transport Process in Sieve Tubes The metabolites of all the mesophyll cells around the sieve elements join in a common pool to load via the surrounding transfer cells. The path of metabolites and other solutes is shown in Figure. Presum
Xylem and phloem are called complex tissues because they contain more than one type of cells, which performs vital functions in plants. Xylem is meant for the conduction of sap (water and mineral) and phloem is meant for…
Unlike xylem (which is composed primarily of dead cells), the phloem is composed of still-living cells that transport sap. The sap is a water-based solution, but rich in sugars made by photosynthesis. These sugars are transported to non-photosynthetic parts of the plant, such as the roots, or into storage structures, such as tubers or bulbs. During the plants growth period, usually during the spring, storage organs such as the roots are sugar sources, and the plants many growing areas are sugar sinks. The movement in phloem is multidirectional, whereas, in xylem cells, it is unidirectional (upward).[citation needed] After the growth period, when the meristems are dormant, the leaves are sources, and storage organs are sinks. Developing seed-bearing organs (such as fruit) are always sinks. Because of this multi-directional flow, coupled with the fact that sap cannot move with ease between adjacent sieve-tubes, it is not unusual for sap in adjacent sieve-tubes to be flowing in opposite ...
Wild Bluegreen Blend is an even blend of Bluegreen Body and Bluegreen Mind algae in powder form in a 3.5 oz. size.. Wild Bluegreen Body is the whole, complete algae, and provides essential fatty acids, proteins, complex sugars, vitamins, minerals, and essential amino acids. Because its cell walls are composed of peptidoglycan (carbohydrates and peptides), lipids (oils), polysaccharides (sugars), and proteins, Wild Bluegreen Body provides an easily digestible natural complex that is critical for the health and vitality of tissues and cells. Wild Bluegreen Body also contains high concentrations of easily assimilated vital minerals and amino acids.. Wild Bluegreen Mind is the heart of the algae with the cell wall carefully removed through our special separation process. Wild Bluegreen Mind is an abundant source of raw materials for enhancing brain activity. The amino acids found in Wild Bluegreen Mind are the building blocks of the healthy nerve cells and neurotransmitters vital for proper brain ...
Above those lies a broad band of blue-fluorescing thin-walled cells that are very small and arranged like piles of bricks. This is the cambium - the plants stem cells that divide continuously to produce new xylem on the inside and new phloem elements on their outer surface. The small, bright blue-fluorescing cells on the outside of the cambium are the phloem sieve tubes and associated companion cells, which conduct sugars produced by photosynthesis in the leaves to other parts of the plant. ...
Squamous Epithelium a single layer of flat cells that line the surface. They are found primarily on the alveoli in the lungs.. Ciliated Epithelium covered in cilia, found on the surface where things are moved.. Muscle Tissue is made up of bundles of elongated cells called muscle fibres. There are three types: smooth, cardiac, and skeletal. Cartilage a connective tissue found in the joints. It is used for shape and support.. Xylem Tissue is a plant tissue with two jobs, it transports water around the plant and supports it. It contains hollow xylem vessels, which are dead, and living parenchyma cells.. Phloem Tissue transports sugars around the plant. Its arranged in tubes and is made up of sieve cells, companoon cells, and some ordinary plant cells. ...
Plants have a conductive tissue, phloem, for transporting sugars and hormones to non-green parts after photosynthesis. Phloem has two basic cell types, enucleate sieve elements (SE) and companion cells (CC). Scientists from the University of Helsinki have developmentally analyzed the process of phloem development in Arabidopsis plant and identified a mutation in a novel gene that is required for instructing phloem differentiation in young, developing plant tissue. Their article is published in Nature on 13th of November. ...
The phloem is the plant tissue that carries the products of photosynthesis (sugars) from sites of production (leaves and other green parts of the plant) to sites of consumption. In trees, the phloem is located just below the bark. The phloem comprises cylindrical cells lying end-to-end, forming a fluidic network spanning the entire length of the plant.. Sugar transport in plants occur in the phloem vascular system. The products of photosynthesis are transported from sources (mature leaves) to sinks (e.g. shoots, roots and fruits) in this microfluidic channel network. The sap flowing in the plant veins contains 15% to 25% sugar, mostly sucrose (table sugar), and moves at speeds of approximately one meter per hour. To drive transport, a remarkably large cell pressure is required in the leaf phloem: 10 to 20 atm. This is almost 100 times larger than typical human systolic blood pressure. Sugars are believed to play a fascinating dual role in generating this pressure, acting both as an energy ...
A tree like this likely has a thin bark, with its phloem layer close to the surface. The hardest part of the tree (the wood) is actually beneath the phloem, so the bug doesnt have to pierce wood. The phloem sap is the good stuff, carrying most of the processed sugars and nutrients with high caloric content, and that is what these little guys are after. So Im not surprised that this behavior can occur, but... I can imagine easier ways of getting phloem sap. Leaves are what Id normally pick, but ...
Stock and flow models of housing should be driven by empirical schedules of mortality. A selection of analytic, life table, and stock and flow models used to estimate the mortality of housing are examined. The assumptions which underpin each of these models, data difficulties, issues of validation and misapplication of mortality indicators are addressed. A stock and flow model is used to estimate the energy and mass flows required to sustain dwelling services in the companion paper (Johnstone IM. Energy and mass flows of housing: a model and example. Building and Environment 2000;36(1):27-41).. ...
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In todays world air pollution is highlighted more and more as an environmental issue, due to its role in causing damage to human health.. Atmospheric particle matter (PM). PM2.5 particles which are less than 2.5 um diameter are one of the units for atmospheric pollution that need measuring. HORIBA have developed the APDA-375A which can measure the PM 2.5, the system includes a gas mass flow measurement system.. Gas Mass Flow controller (MFC) ensures accurate gas control with good repeatability if the temperature and pressure changes due to the environment changing, this is a very important for air pollution measurement equipment.. HORIBA can offer suitable fluid control systems according to customer specification.. ...
Ross-Elliott TJ, Jensen KH, Haaning KS, Wager BM, Knoblauch J, Howell AH, Mullendore DL, Monteith AG, Paultre D, Yan D, Otero-Perez S, Bourdon M, Sager R, Lee JY, Helariutta Y, Knoblauch M, Oparka KJ (2017) Phloem unloading in Arabidopsis roots is convective and regulated by the phloem-pole pericycle. Elife.. http:/​/​dx.​doi.​org/10.7554/eLife.24125. Open Access. Karl Oparka (University of Edinburgh) is the corresponding author of this study that includes researchers from the UK, US and Denmark. Movement of solutes and macromolecules through the plant phloem is key for the correct distribution of nutrients allowing for optimal growth. In this paper they discover that unloading of molecules from the phloem occurs via a set of specialized funnel plasmodesmata that link the phloem to adjacent pericycle cells. Remarkably they find that whereas solutes are constantly unloaded, larger proteins are released through these plasmodesmata in discrete pulses, which they describe as batch ...
The sinusoids are unique exchange vessels composed of specialized nonparenchymal cells that exhibit structural and functional heterogeneity. The structure of the sinusoid is illustrated in Figure 3. The endothelial cells are highly fenestrated and lack a supporting basal lamina. The fenestrae are organized in clusters known as sieve plates. As a result, there is continuity between the plasma in the sinusoid lumen and the perisinu-soidal space (of Disse). The sinusoidal endothelial cells contain.... ...
Companion cell definition, any of a number of specialized parenchymal cells adjacent to a sieve tube in the phloem of flowering plants, believed to regulate the flow of nutrients through the tube. See more.
The two big eyes in this smiley face (which is typical of a monocot vascular bundle) are metaxylem elements that transport water through the leaf. The bright blue fluorescence in the mouth of the smiley face is phloem, composed of larger sieve tubes and smaller rectangular (in cross section) companion cells, which together transport sugars, made by photosynthesis, out of the leaf. The bright yellow cells forming the neck of the smiley face are lignified, providing a measure of rigidity in the leaf, and the band of cells along the bottom of the section are epidermal cells covered by a cuticle. ...
Note that cells in the foundation idea tend not to have vacuoles. As soon as in the foundation cell cytoplasm, Mg2+ travels toward the centre of the root by plasmodesmata, where it is loaded into the xylem (five) for transport for the higher portions of the plant. Once the Mg2+ reaches the leaves it truly is official site unloaded with the xylem into cells (six) and again is buffered in vacuoles (7). No matter if cycling of Mg2+ in the phloem happens by way of typical cells during the leaf (8) or straight from xylem to phloem by means of transfer cells (9) is unidentified. Mg2+ may well return to your roots in the phloem sap ...
Apparatus for measuring the mass flow of a fluid within a defined fluid stream including a conduit having two substantially parallel, flexible and continuous flow tubes fixedly mounted at their ends to a centrally positioned housing forming a flow splitter and a flow converger for directing the flow from the inlet and for directing the flow into the outlet between the apparatus and the fluid stream. The ends of each flow tube positioned proximal to one another and to the center of gravity formed by the shape of the flow tube. Each flow tube substantially forming a B shape having a first loop, a connecting portion and a second loop. The first and second loops being symmetrical with respect to the connecting portion and extending laterally from the center of gravity at a greater distance than the displacement of the connecting portion to the center of gravity. The flow tubes being oscillated in opposing modes at the connecting portion so as to produce a measurable Coriolis reaction force by the fluid on
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A pressurized cylindrical tank, 5.0 m in diameter, contains water which emerges from the pipe at point C, with velocity 29 m/s. Point A is 10 m above point B and point C is 3 m above point B. The area of the pipe at point B is 0.08 m^2 and the pipe narrows to an area of 0.04 m^2 at point C. Assume water is an ideal fluid in laminar fluid. The density of water is 1000 kg/m^3. The mass flow rate in the pipe is closest to ...
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I am a high school student doing a science project on plant sap , production. I need to grow a plant, remove the sap and then measure the , sugar content. Does anyone have a suggestion on how to remove the sap , and then measure the sugar content. Hello, Jen. One way to do this on a living plant is to use an aphid. These insects puncture stems with their mouth-parts and find the phloem: Then, you cut the aphids body off its head, leaving the mouth-parts still in the phloem of the plant stem. I know - it sounds gruesome... Drops of the solution from the phloem can be collected from the aphid head with a pipette. This also happens from the holes left in stems and leaves when aphids feed naturally, and it makes them sticky. The technique is called Aphid stylectomy: http://www.biosciences.bham.ac.uk/labs/pritchard/techniqu.htm Another possibility is to make very fine micro-pipettes by heating glass tubing in a Bunsen burner flame and then pulling it apart very quickly when it starts to melt (BE ...
Were now in a position to model the entire flow of sucrose, from leaf to root. As weve established, the hydraulic flow across the xylem:phloem boundary, as well as down the phloem in the trunk, can be modeled as a given pressure giving rise to some flow, related by an effective resistivity \\(\\mathcal\{R\}\\\) just as in electronic circuits. In fact, we can take the analogy further. The water loads the phloem ...
A coordinated supply of the whole plant with sulfur (S) and nitrogen (N) requires mechanisms to regulate not only uptake and assimilation but also long-distance transport of both nutrients in the phlo
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Stitt, M.; Brauer, M.; Quick, W. P.; Neuhaus, H. E.; Fichtner, K.; Schulze, E.-D.; Guenther, L.; Heineke, D.; Heldt, H. E.; Sonnewald, U. et al.; von Schaewen, A.; Willmitzer, L.: Regulation of metabolism: biochemical and genetic studies. In: In Recent Advances in Phloem Transport and Assimilate Compartmentation, pp. 10 - 19 (Eds. Bonnemain, J. L.; Delrot, S.; Lucas, W. T.; Dainty, J.). Quest Editions, Nantes, FRA (1991 ...
Stitt, M.; Brauer, M.; Quick, W. P.; Neuhaus, H. E.; Fichtner, K.; Schulze, E.-D.; Guenther, L.; Heineke, D.; Heldt, H. E.; Sonnewald, U. et al.; von Schaewen, A.; Willmitzer, L.: Regulation of metabolism: biochemical and genetic studies. In: In Recent Advances in Phloem Transport and Assimilate Compartmentation, S. 10 - 19 (Hg. Bonnemain, J. L.; Delrot, S.; Lucas, W. T.; Dainty, J.). Quest Editions, Nantes, FRA (1991 ...
Every patient dependent on a ventilator for respiration is vulnerable. Intubated individuals face risks - such ventilator-associated events, oral pressure ulcers, and unexpected tube occlusions - that can result in longer lengths of stay and increased hospital costs.1. Our AnchorFast oral endotracheal tube fasteners help you address intubated patient risks with confidence. Our products offer the right combination of features for your patients needs, and are designed to provide many clinical benefits, including: ...
வேர்கள், அடிமரம், கிளைகள், சிறுகிளைகள், இலைகள் என்பவை மரத்தின் பகுதிகளாகும். மரத் தண்டு, தாங்குவதற்கானதும், நீர், உணவு முதலியவற்றைக் கடத்துவதற்குமான மென்சவ்வுகளைக் (காழ் (xylem) மற்றும் உரியம் (phloem)) கொண்டது. மரம் (மூலப்பொருள்), காழ்க் கலங்களைக் கொண்டது, மரப்பட்டை முக்கியமாக உரியங்களால் ஆனது. மரம் வளரும்போது இது ஆண்டு வளையங்களை உருவாக்குகின்றது. மிதவெப்ப மண்டலக் (temperate) காலநிலைப் ...
(a) Apoplasmic transport (figure) Figure 5.32 Mechanistic model for plasma membrane transport of sucrose from the coat and into the cotyledons of a developing legume seed.