Choline contributes to increase some pathogenic factors in different Pseudomonas syringae strains.

PRIMO, E.D., GARRIDO, M.N., GIORDANO, W.F., LISA, A.T.

Congreso; Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2014

P. syringae infects a wide variety of plants and causes necrotic symptoms in leaves, stems, and fruit. It is considered a hemibiotrophic pathogen because it is able to obtain nutrients from living host cells in order to multiply in the apoplast and infect close tissues. Choline (Cho), an alkylammoniun compound, is a normal constituent of plant tissues and in the apoplast is found as a component of phosphorylcholine (Pcho). P. syringae pv. tomato, P. syringae pv. tabaci, and a local strain that we isolated and named S5, use Cho as nitrogen source. These strains produce the enzyme phosphorycholine phosphatase (PchP), capable to generate free Cho from Pcho. In S5, Cho increases at least two virulence factors: tabtoxin and swarming mobility. S5 was isolated from oat leaves from a south field of Córdoba, and the strain was characterized in our laboratory by bioinformatic, microbiology, biochemical and molecular approaches. By the analysis of ARN16S, S5 was classified as P. syringae pv. atropurpurea. The BOX fingerprint of S5 resulted similar to those of P. syringae isolated from different host plants of our area. We conclude that S5 is a potentially dangerous bacterium, able to obtain nutrients from host and enhance the production of virulence factors; it is widely spread in nature, and is capable to cause infection in different plants of economic importance as peanut and soybean.