INTERACTION BETWEEN Pseudomonas stutzeri MJL19 AND SOYBEAN PLANTS IN SALINE STRESS

LAMI, MARÍA JESUS; CARAM DI SANTO, MARÍA CAROLINA; ZENOFF, ANA; RUBIO, ANNA CAROLINA; BULACIO GIL, NATALIA; POMARES, FERNANDA; ADLER, CONRADO; VINCENT, PAULA; ESPINOSA-URGEL MANUEL; DE CRISTOBAL, RICARDO EZEQUIEL

SALTA

Congreso; SAIB PABMB; 2019

Root surrounding is a highly complex ecosystem influenced by roots secretions and by microbial activity in the soil. During colonization and adaptation to life in the rhizosphere, bacteria modify gene expression affectingmetabolism, mobility, chemotaxis, EPS synthesis and secretion. The interaction of the bacterium P. stutzeri MJL19 with soybean root was studied by RT-qPCR transcriptional analysis of genes potentially related to colonizationand abiotic stress response. We analyzed the expression of genes involved in root colonization (algA, bcsA, oprF, clpP, putA and putP) and genes coding for chaperones responsible for the proper folding of stress-damagedproteins, superoxide dismutase and production of protective osmolites (i.e dnaJ, proC and sodC).We found higher expression of clpP, oprF, algA, bcsA, putA and putP when MJL19 was attached to soybean root in saline conditions compared with MJL19 growing in the absence of the plant. In the case of clpP and oprF thedifference in root expression was about 5 fold greater in the saline condition with respect to the non-saline one. In contrast, NaCl in absence of soybean roots did not generate significant changes in the expressions.The expression of genes related to abiotic stress, dnaJ and proC, showed greater expression in populations of MJL19 attached to the soybean root in saline stress, meanwhile sodC decreased its expression under this condition.In P. stutzeri MJL19 genes related to colonization and formation of biofilms such as oprF, clpP, algA and bcsA are expressed in the presence of soybeans roots exposed to saline stress, indicating that the bacterium is prone togrow as a biofilm when it is in the presence of the soybean root. Expression of the gene involved in the proline biosynthesis (proC) and expression of the chaperone DnaJ (dnaJ) are low when MJL19 is in presence of soybean innon-saline condtions. However, when MJL19 is in contact with soybean root in saline conditions the expression both genes expression is substantially enhanced.