POSTER NO: 431

Molecular Biological Analysis of the Mutated Rice Induced by Space Environment

Changyin Li, Yeqing Sun
Department of Life Science and Engineering, Harbin Institute of Technology, Harbin 150001, China

Seeds of rice Wudao3 were carried on recoverable satellite in 1996. After 3 years' breeding and selecting, some new varieties with rice blast resistance, is obtained. 973-5 is a rice blast resistance variety. The rice blast resistance gene pi-ta conforms to the gene-for-gene fashion. Pi-ta(-) alleles in susceptible rice varieties encode proteins that share a single amino acid difference relative to those of pi-ta(+) alleles in resistant varieties: serin instead of alanine at position 918. Using a RT-PCR strategy, we cloned pi-ta gene in rice 973-5 and its ground control rice 973ck(Wudao3). Pi-ta alleles in rice 973ck which encode proteins with serin at position 918 prove to be non-resistance, while pi-ta alleles in rice 973-5 have two deletion mutant: 6009-6157 and 6554- 6725. A terminator TGA forms at 6186-6188 by the first mutation and the c-term of pi-ta encoding proteins are changed: a 10-residue peptide instead of a 222-residue one, which probably relates to the rice blast resistance of rice 973-5.