Identification of a Lectin Gene Induced in Rice in Response to Magnaporthe grisea Infection
QIN Qing-Ming, ZHANG Quan, ZHAO Wen-Sheng, WANG Yun-Yue, PENG You-Liang(1. Department of Plant Pathology, China Agrucultural University, Beijing 100094, China; 2. Department of Plant Pathology, Yunnan Agricultural University, Kunming 650201, China)
By mRNA differential display, eight induced cDNAs were obtained from rice leaves infected with an incompatible race 131 of Magnaporthe grisea, and one of these cDNAs was highly similar to salt-induced mannose-binding lectin gene. Using this fragment as a probe, a full length cDNA was isolated from a rice cDNA library, which was constructed using mRNA from the incompatible race-infected leaves. Sequence analysis indicates that the cDNA encodes a protein of 15 kD with 145 amino acids and shares 96% identity at nu-cleotide level with MRL and salT, but is identical to MRL at amino acid level. Genomic Southern blotting shows that there are two mannose-binding lectin genes in rice genome. Northern blotting analysis indicates that the gene was strongly and specifically induced in rice leaves infected with the incompatible race, suggesting that the lectin induction be involved in the defense of rice to M. grisea.