Query: NC_008380:2210649 Rhizobium leguminosarum bv. viciae 3841, complete genome
Lineage: Rhizobium leguminosarum; Rhizobium; Rhizobiaceae; Rhizobiales; Proteobacteria; Bacteria
General Information: This biovar nodulates legumes in the Tribe Viciae (Vicia, Pisum, Lathyrus, Lens). This strain is a spontaneous streptomycin-resistant mutant of strain 300. Nitrogen-fixing plant symbiont. This organism, like other Rhizobia, establishes a symbiotic relationship with a legume plant, providing nitrogen in exchange for a protected environment. The legume roots secrete flavonoids and isoflavonoids which the bacteria recognize and use to turn on genes involved in root nodulation. Many of the root nodulation genes are involved in synthesis and secretion of a nodule inducing signal, a lipochito-oligosaccharide molecule, which the plant recognizes, triggering nodule formation. The bacterium is endocytosed and exists inside a membrane bound organelle, the symbiosome, and fixes nitrogen for the plant cell while the host cell provides carbon compounds for the bacterium to grow on. The nitrogen fixation is important as it obviates the need for expensive and environmentally damaging fertilizer use.
Subject: NC_004578:4204235 Pseudomonas syringae pv. tomato str. DC3000, complete genome
Lineage: Pseudomonas syringae group genomosp. 3; Pseudomonas; Pseudomonadaceae; Pseudomonadales; Proteobacteria; Bacteria
General Information: While pathogenic on Arabidopsis thaliana, it is mainly characterized as causing bacterial speck disease on tomato plants, which has a large economic impact. This organism is mainly endophytic and is a poor colonizes of plant surfaces but can multiply within the host. Bacteria belonging to the Pseudomonas group are common inhabitants of soil and water and can also be found on the surfaces of plants and animals. Pseudomonas bacteria are found in nature in a biofilm or in planktonic form. Pseudomonas bacteria are renowned for their metabolic versatility as they can grow under a variety of growth conditions and do not need any organic growth factors. This species includes many plant pathogens of important crops, which makes it a model organism in plant pathology. Its natural environment is on the surface of plant leaves and it can withstand various stressful conditions, like rain, wind, UV radiation and drought. It can colonize plants in a non-pathogenic state and can rapidly take advantage of changing environmental conditions to induce disease in susceptible plants by shifting gene expression patterns.