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Genome dynamics and pathogen resistance

Team GDYNPATH / Valerie Geffroy


Preservation of genome stability and integrity is the primary task for every organism, including plants. At the same time, plant genome needs to adapt to changing environments, including pathogens stresses. Biotic stresses caused by viruses, fungi, bacteria, weeds, insects and other pests and pathogens are a major constraint to agricultural productivity. The use of resistant (R) genotypes is the most economic and ecologically safe means for controlling plant diseases. Consequently, disease R genes are a crucial component for sustainable agriculture. At the molecular level, most cloned R genes encode intracellular proteins containing a nucleotide-binding (NB) site and a leucine rich-repeat (LRR) domain (NL). R genes belonging to this class have been identified in all plant species and are effective against all types of pathogens. Our research aimed at a better understanding of the molecular basis of resistance in legume using genetic, genomics and phytopathology tools. We are working with two crop legume species: common bean (Phaseolus vulgaris) and pea (Pisum sativum). Common bean is the most important grain legume for direct human consumption in the world, particularly in developing countries where it constitutes the main source of proteins. Pea is of great importance in Europe and in particular in France where it is cultivated for its protein content and ability to fix atmospheric nitrogen.

Our aim is to obtain a better understanding of the evolution of disease resistance genes in plants with special focus on the common bean genome. Three principal research areas are developed:

  • Genome wide analysis of NL genes in common bean genome.
  • Development and implementation of VIGS in common bean and pea using BPMV.
  • Plant resistance in the context of climate change and organic farming.

To attain our aims, we are combining structural and comparative genomics approaches, high-throughput sequencing (DNA, small RNA, methylome), classical genetic analysis, and pathogenicity tests with 2 pathogens [the fungus Colletotrichum lindemuthianum –agent of anthracnose-, the virus BPMV (Bean pod mottle virus)]. We are also developing FISH (Fluorescence In Situ Hybridization) analyses in collaboration with Prof. A. Pedrosa-Harand (Brazil).

We hope that our work, including genetic and cutting edge genomics approaches, on an important crop legume species, will produce knowledge of both academic and applied importance and will help to promote sustainable agriculture (EU BRESOV project) in the context of climate change (ANR HiPATH).