The evolution of resistance genes in multi-protein plant resistance systems.

TitleThe evolution of resistance genes in multi-protein plant resistance systems.
Publication TypeJournal Article
Year of Publication2007
AuthorsFriedman AR, Baker BJ
JournalCurr Opin Genet Dev
Volume17
Issue6
Pagination493-9
Date Published2007 Dec
ISSN0959-437X
KeywordsChromatin Assembly and Disassembly, Directed Molecular Evolution, Evolution, Molecular, Genes, Plant, Genome, Plant, Immunity, Innate, Models, Genetic, Multigene Family, Plant Diseases, Plants, Recombination, Genetic
Abstract<p>The genomic perspective aids in integrating the analysis of single resistance (R-) genes into a higher order model of complex plant resistance systems. The majority of R-genes encode a class of proteins with nucleotide binding (NB) and leucine-rich repeat (LRR) domains. Several R-proteins act in multi-protein R-complexes that mediate interaction with pathogen effectors to induce resistance signaling. The complexity of these systems seems to have resulted from multiple rounds of plant-pathogen co-evolution. R-gene evolution is thought to be facilitated by the formation of R-gene clusters, which permit sequence exchanges via recombinatorial mispairing and generate high haplotypic diversity. This pattern of evolution may also generate diversity at other loci that contribute to the R-complex. The rate of recombination at R-clusters is not necessarily homogeneous or consistent over evolutionary time: recent evidence suggests that recombination at R-clusters is increased following pathogen infection, suggesting a mechanism that induces temporary genome instability in response to extreme stress. DNA methylation and chromatin modifications may allow this instability to be conditionally regulated and targeted to specific genome regions. Knowledge of natural R-gene evolution may contribute to strategies for artificial evolution of novel resistance specificities.</p>
DOI10.1016/j.gde.2007.08.014
Alternate JournalCurr Opin Genet Dev
PubMed ID17942300