Expression Profile During the Development of Appressoria Induced by Hydrophobic Surfaces in Magnaporthe grisea Y34

To study the gene expression profile during appressorium developmental process of Mugnaplzorthe grisea strain Y34 isolated from the rich area of Asia cultivated rice resources, expressed sequence tags (ESTs) and cDNA array analysis were performed. A total of 4756 tentative unique transcripts (TUTs) were obtained from 13 057 ESTs of the 3' ends of the strain, which was approximately 25% of the total M. grisea EST sequences deposited in the GenBank database. Approximately 84% of these TUTs matched with the published draft genome sequences of strain 70-15. Southern analyses with 12 TUT probes revealed no obvious DNA polymorphism among strains 70-15, Guy11 and Y34. A cDNA array with 4108 TUTs was used to monitor gene expression patterns during appressorium development of M. grisea. Compared with ungerminated conidia, the number of up-regulated and down-regulated genes was almost consistent at any time-points of 2, 8, 20 and 30 h during appressorium development. More genes were differentially expressed during appressorium maturation (20 and 30 h) than during appressorium induction (2 h) and formation (8 h). During appressorium maturation (20-30 h), genes generally seemed to be most actively expressed.