Plant & Animal Genomes XIV Conference Plant & Animal Genomes XIV ConferenceJanuary 14-18, 2006
Town & Country Convention Center
San Diego, CA
You-Liang Peng*, Shiping Wei, Xiaoyan Zhao, Shengli Ding, Junli Huang, Xingxia Ma, Kai Zhang, Yujun Zhang, Tao Shi, Weixiang Wang, Maohua Li, Jun Yang, Xuekun Zhao, Baohua Liu, Jingyu Liu, Zhaohui Wen, Huifeng Wang, Jing Sun and Suxia Ma
Department of Plant Pathology, China Agricultural University, Beijing 100094, China
*Author for correspondence:pengyl@public3.bta.net.cn
Magnaporthe grisea is the causual agent of rice blast that is one of the most devastating diseases in rice growing countries. The fungus infects host plants by elaborating a process involving such key steps as conidiation, appressorium formation, penetration and invasive growth of infection hyphae. Understanding of molecular mechanisms underlying the steps will contribute much to design of novel control approaches to the disease. By using the methods of restriction enzyme-mediated insertion and Agrobacterium tumefacience-mediated transformation, a systemic insertion mutant library with more that 70000 transformants was generated in M. grisea. From the library, more than 200 mutants were obtained that are defective in one of the above infection steps, and phenotype mutation in more than one third of the mutants was confirmed to be co-segregated with the insertion marker. By gene complementation and replacement, we so far proved 11 novel genes in the pathogen that enhance or are required for conidiation, conidial shaping, appressorium formation and maturation, penetration peg formation or/and invasive growth of infection hyphae. Of the 11 genes, seven seem to be fungi-specific as verified by bioinformatics analysis. Intensive characterization is now underway to verify the nature, subcellular localization, expression profiles of the gene products. The fungi-specific genes identified in M. grisea provide potential targets to design novel fungicides for the disease control.