Vladimir A Zhukov
All-Russia Research Institute for Agricultural Microbiology, Russia
Title: Molecular evolution of paralogous symbiotic receptor kinase genes in pea (Pisum sativum L)
Biography
Biography: Vladimir A Zhukov
Abstract
In the course of interactions between legume plants and nodule bacteria, the signal molecules excreted by bacteria (Nod
factors) are specifi cally perceived by plant receptor kinases. In pea, 3 paralogous genes (Sym37, K1 and LykX) encoding
receptor kinases probably binding Nod factors are located in cluster on LG I of pea and mutations in any of these genes hamper
bacteria penetration into the plant root. In this work, the fragments of 1st exons of the genes Sym37, K1 and LykX encoding
the receptor parts of the corresponding proteins were sequenced and analyzed in 99 pea genotypes that represent virtually all
the diversity within the genus Pisum. Th e Sym37 gene sequence, according to the McDonald-Kreitman test, underwent the
pressure of positive (directional) selection. Th e K1 gene sequence possesses multiple polymorphic sites, suggesting that the
positive selection acts in favor of several allelic states of the gene. Th e sequence of the third receptor gene (LykX) possesses
the site, which seems to be critical for the functioning of the encoded protein; this site was found to be under the signifi cant
negative selection pressure. Th e assumption that these paralogous genes were diff erentiated for realization of the diverse
functions is reinforced by the results obtained. In general, the data obtained provide insights on the evolution and functioning
of symbiotic systems formed by leguminous plants.