Plant & Animal Genomes XIV Conference

January 14-18, 2006
Town & Country Convention Center
San Diego, CA

Whole Genome Insertional Mutagenesis And Gene Function Identification In Magnaporthe grisea

Yan Meng¹ , Gayatri Patel¹ , Melanie Clowford¹ , Melania Betts² , Sara L. Tucker² , Nicole Donofrio³ , Thomas Mitchell³ , Ralph Dean³ , Marc J. Orbach² , Mark Farman¹

¹  University of Kentucky, Lexington, KY 40546, US

²  University of Arizona, Tucson, AZ 85721, US

³  North Carolina State University, Raleigh, NC 27695, US

Magnaporthe grisea is the causal agent of rice blast disease, which is the most destructive fungal disease of rice worldwide. Our goal is to identify genes required for pathogenicity and fitness, as they are good candidates for the development of durable resistance. An insertional mutagenesis approach to saturate the Magnaporthe genome was utilized to reach this goal, over 50,000 random insertion transformants of M. grisea strain 70-15 have been generated mostly by using Agrobacterium-mediated transformation. The phenotypes of all strains, including pathogenicity, metabolism and morphology have been analyzed and all the data about the mutants are available via a web-based database (MGOS: http://www.mgosdb.org). An inverse-PCR approach was developed to recover sequences flanking insertion sites in mutants compromised in pathogenicity and forty-nine tagged genes were recovered. Six of these genes were transformed back into the corresponding mutant. All six complemented the defect, confirming that these genes function in pathogenicity.