In rice, at least 40 genes conferring resistance to blast (caused by Magnaporthe grisea) have been described since 1985 (Sallaud et al, 2002), but only two were cloned (Pib [Wang et al 1999] andPita [Jia et al 2000]). These genes belong to the nucleotide-binding site-leucine-rich repeat) (NBSLRR) family of plant resistance genes. Direct molecular interaction between the protein encoded by Pita and the corresponding M. grisea avirulence gene product AVR-PITA (a small secreted protein) has been demonstrated (Jia et al 2000). Therefore, the recognition of fungal protein produced during the early stages of the infection process is the initial step in the resistance to blast controlled by Pita. Other known M. grisea avirulence genes encode for small proteins that are likely to be secreted during infection. They are involved in nonhost resistance either in weeping lovegrass or in rice.