Buchnera: A genus of gram-negative bacteria which are obligately intracellular endosymbionts of APHIDS. The bacteria are found within specialized cells in the aphid body cavity.Aphids: A family (Aphididae) of small insects, in the suborder Sternorrhyncha, that suck the juices of plants. Important genera include Schizaphis and Myzus. The latter is known to carry more than 100 virus diseases between plants.Symbiosis: The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.Anthranilate Synthase: An enzyme that catalyzes the formation of anthranilate (o-aminobenzoate) and pyruvic acid from chorismate and glutamine. Anthranilate is the biosynthetic precursor of tryptophan and numerous secondary metabolites, including inducible plant defense compounds. EC 18.104.22.168.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Luteovirus: A genus of plant viruses that infects both monocotyledonous and dicotyledonous plants. Its organisms are persistently transmitted by aphids, and weeds may provide reservoirs of infection.Serratia: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the natural environment (soil, water, and plant surfaces) or as an opportunistic human pathogen.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Gammaproteobacteria: A group of the proteobacteria comprised of facultatively anaerobic and fermentative gram-negative bacteria.Amino Acids, Essential: Amino acids that are not synthesized by the human body in amounts sufficient to carry out physiological functions. They are obtained from dietary foodstuffs.Chaperonin 60: A group I chaperonin protein that forms the barrel-like structure of the chaperonin complex. It is an oligomeric protein with a distinctive structure of fourteen subunits, arranged in two rings of seven subunits each. The protein was originally studied in BACTERIA where it is commonly referred to as GroEL protein.Genome Size: The amount of DNA (or RNA) in one copy of a genome.