Abstract
We have generated approximately 10,000 activation tagging rice lines. Among them, a lesion mimic mutant, which we designated Lesion mimic 1 (Lmm1), was further characterized. Lmm1 was dominant and the mutant phenotype was co-segregated to the T-DNA in the T1 generation. An ORF was located about 500 bp downstream of the T-DNA and the lesion mimic phenotype correlated with the enhanced expression of the mRNA. The encoded protein shows sequence similarity to a protein whose expression is induced by hypersensitive reaction in tobacco. In addition, transcriptional levels of PR proteins were increased and phytoalexins, both momilactone A and sakuranetin, accumulated in Lmm1. Further, T1 plants which exhibit lesion mimic were resistant to rice blast, which strongly suggests the correlation between the encoded protein and defense mechanism.
This work was supported by a grant from the Ministry of Agriculture, Forestry and Fisheries of Japan (Rice Genome Project MP-1202).
