Submitted to: International Plant Protection Congress
Publication Type: Abstract Only
Publication Acceptance Date: 5/11/2003
Publication Date: 5/11/2004
Citation: Jia, Y., Wang, Z., Singh, P., Rutger, J.N., Martin, R., Pinson, S.R. 2004. Development and characterization of rice mutant populations for functional genomics of host-parasite interactions [abstract]. 15th International Plant Protection Congress Proceedings. p. 64.
Technical Abstract: Plant resistance (R) genes are proposed to serve at front lines of defense against pathogens and thus R genes play central roles for crop protection. Understanding molecular mechanisms of R gene mediated defense responses should facilitate the development of both conventional and novel strategies for disease control. To dissect the R gene-mediated signal transduction pathways the blast resistant US rice cultivar Katy was mutagenized by ethyl methane sulfonate (EMS) and fast neutrons. For EMS, seeds were soaked in 0.4%, 0.8% and 1.2% EMS solutions for 6 hours and a total of 7199 M1 mutant lines were recovered. For fast neutron, seven dosages of fast neutron were applied and a total of 15400 M1 mutant lines were recovered only from treatments with 7.7 Gray, 26.3 Gray and 49.4 Gray. Preliminary analysis of M2 seedlings revealed defects in chlorophyll synthesis in approximately 4% of M1 derived lines. Katy containing the Pi-ta R gene prevents the infection of Magnaporthe grisea races in a gene for gene manner. M. grisea races containing the avirulence gene AVR-Pita are being used to identify susceptible mutants. One Sekiguchi lesion mimic-like mutant of Katy (LMM1) was recovered from a mutant population induced by EMS. Pronounced lesions were only induced by an incompatible M. grisea race IE1k, not by any compatible races tested. Progress on analysis of the genetic locus that controls lesion mimic, structure of AVR-Pita from IE1k and current models of host-parasite interaction will be discussed.