RESPONSE OF DIVERSE RICE GERMPLASM TO BIOTIC AND ABIOTIC STRESSES
Location: Dale Bumpers National Rice Research Center
Title: Characterization of rice lesion mimic mutants of 93-11 for a better understanding of general host defense response to both rice blast and sheath blight diseases
Submitted to: Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 2010
Publication Date: December 2, 2011
Citation: Wang, X., Wu, D., Jia, Y., Zhang, M. 2011. Characterization of rice lesion mimic mutants of 93-11 for a better understanding of general host defense response to both rice blast and sheath blight diseases [abstract]. In: Fifth International Rice Blast Conference, August 12-14, 2010, Little Rock, Arkansas. p. 23.
Rice lesion mimic mutants (LMM) exhibit necrotic lesions resembling programmed cell death (PCD). PCD is one of the significant hallmarks of disease resistance genes mediated defense responses. LMM can be used to study the mechanisms of plant disease resistance.
In the present study, a total of 133 rice lesion-mimic mutants of rice restorer line 93-11, induced by Co60- irradiations, were identified for further characterization. The lesions of the mutants were first observed at the five- to- six-leave stage without any treatment in the field, and all of the lesions have been observed in subsequent generations. Among 133 mutants five distinct phenotypes of LMM were observed. Genetic analysis indicated that each of these five phenotypes was conditioned by a single recessive gene, respectively. Sequencing analysis of the cloned lesion mimic genes between 93-11 and mutants indicated that those five phenotypes were controlled by novel genes. Bacterial blight isolate IV and blast isolates ZF1 and ZG1 were inoculated separately on to these LMMs during pathogenicity assays. Results of pathogenicity assays demonstrated that these mutants exhibited significantly enhanced resistance to both rice blast and bacterial blight diseases. These findings suggest that the lesion mimic mutations in rice may be involved in general disease resistance.
Progress on mutant characterization for enhanced disease resistance, genetic mapping and cloning will be presented.
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