Submitted to: International Congress on Molecular Plant-Microbe Interactions
Publication Type: Abstract Only
Publication Acceptance Date: 4/11/2001
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Rice blast caused by Magnaporthe grisea is one of the most destructive diseases in the rice growing areas. Management of disease through host resistance has been considered to be an economically viable and sustainable strategy. However, resistance is frequently overcome by the pathogen. We are investigating molecular mechanisms involved in the evolution of virulence in the pathogen as well as evolution of resistance in the host to gain a better understanding of the molecular basis of this host-pathogen interaction. A Blast resistance locus in indica rice line CO39 (Pi-CO39(t)), corresponding to avirulence gene AVR1-CO39 of M. grisea , has been mapped to the short arm of chromosome 11. Comparative sequence analysis of blast resistant (CO39- indica) and blast susceptible (Nipponbare- japonica) rice genotypes in genomic regions co-segregating with Pi-CO39(t) showed that the two haplotypes are substantially diverged with respect to relative number, size, orientation and location of NBS-LRR genes. All the predicted resistance genes belong to non-TIRNBS-LRR subfamily of plant disease resistance genes which are more abundant in monocot genomes. The functional role, if any, of these putative disease resistance genes is being inferred by fine mapping, the comparative gene structure in disease resistant/susceptible rice cultivars as well as expression studies.