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.
Pathogen stress is one of the most common complex and damaging stresses for plants. To perceive and counter pathogen attack, plants have evolved disease resistance (R) genes.
The largest class of R genes encodes proteins containing a central Nucleotide-Binding Site (NBS) domain, a C-terminal Leucine-Rich Repeat (LRR) domain.
These R proteins detect the presence of disease-causing bacteria, oomycetes, fungi, nematodes, insects, and viruses by sensing either directly or indirectly specific pathogen effectors.
The evolution of new R genes serves to counteract the evolution of novel virulence factors from the pathogens.
NBS–LRR (NL) sequences are often tightly linked at complex loci.
The clustered organization is supposed to favor sequence exchanges, such as unequal crossing over and/or gene conversion events, which can give rise, in some cases, to new (nonparental) R specificities.
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.
Two principal research areas are developed :
● 1. Evolution of resistance gene clusters (Co-2, B4 and Co-x) – to understand their origin and their evolution on various timescales, their link with repeated sequences (such as the khipu satellite)
● 2. Development of VIGS technology for functional genomics – to validate the function of the candidate disease resistance genes