Provorov Nikolai
All-Russia Research Institute for Agricultural Microbiology, Russia
Title: Evolutionary genetics of microbe-plant symbioses: A conduit for constructing the sustainable crop production systems
Biography
Biography: Provorov Nikolai
Abstract
Symbioses of plants with benefi cial microbes implementing numerous nutritional (N2 fi xation, mobilization of soil
phosphates), defensive (biocontrol of pathogens and phytophagans) and anti-stress functions, are widely distributed in
natural ecosystems. These symbioses are broadly used in sustainable agriculture based on substitution of the hazardous chemical
fertilizers and pesticides by the environmentally friendly microbial preparations. Using the model of rhizobia (N2-fi xing
symbionts of legumes) we dissect the microbe-plant co-evolution into three major stages: Pleiotropic symbioses (equilibrium
between mutualistic and antagonistic partners’ interactions); mutual partners’ exploitation (evolutionary stable mutualism
based on the partners’ metabolic exchange) and altruistic interaction (genetic or epigenetic reduction of microsymbionts’
viability resulted in a marked increase of their benefi cial impacts on the host). Based on this strategy, an algorithm for genetic
construction of microbe-plant symbiosis for the sustainable crop production is suggested: Improvement of Principle Benefi cial
Function (PBF) responsible for the plant fi tness (e.g., activation of nitrogenase synthesis or its energy supply); optimization of
host ability to utilize the products of PBF (optimization of plant habitus for maximizing the allocation of N2 fi xation products
from nodules to shoots); improvement of partners’ altruistic interactions based on PBF (in rhizobia-inactivation of the
negative N2 fi xation regulators which result in an increased host benefi t but a decreased ex planta survival). Th e perspectives of
constructing the plants with permanent PBF-implementing organelles (e.g., N2-fi xing plastids) will be considered.