Influence of QS molecules in the interaction between Arachis hypogaea and Bradyrhizobium.

NIEVAS, F.L., BOGINO, P.B., RAMIREZ, K., GIORDANO, W.

Rosario

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

Many bacterial species use small molecules signaling to communicate with each other and to coordinate their growth activities, a process commonly referred to quorum sensing (QS). HSLs are a class of QS signal important for cell to cell communication. In recent years it has been shown that plants are capable to detect bacterial signal molecules and are also able to produce substances mimic and inhibitors of QS. In this work, the effect of root exudates of Arachis hypogaea (peanut) on production of HSLs in Bradyrhizobium native strains and the presence of signal mimic of QS was determinate. The utilization of the biosensor A. tumefaciens NTL4 (pZLR4) in vivo showed an intense production of QS signals in the zone of contact between root-bacteria in comparison to plants control. The result obtained demonstrate that root exudates would determinate a pattern of bacterial colonization and production of HSLs in the rhizosphere of plants. Moreover, it was possible to determine that the plant is capable of synthesize mimic signals which were detected in their root exudates by using an in vitro plate assay with A. tumefaciens NTL4 (pZLR4). However, the structure and biological activity of these plants compounds are still unknown. Our results reveal that an intense process of communication occurs between peanut plants and Bradyrhizobium bacteria in the rhizospheric microenvironment.