Uniformity Among Magnaporthe grisea Isolates on Appressorium Formation by cDNA and Hydrophobicity of Contact Surface

cAMP와 표면 소수성에 의한 도열병균의 부착기 형성

Magnaporthe grisea, a causal agent of blast, forms a specialized infection structure, an appressorium, to infect host. Hydrophobicity of contact surface and cAMP have been suggested as a primary environmental signal and a second messenger to trigger and mediate appressorium formation in this fungus, respectively. To generalize these factors in field isolates of M. girsea, twenty isolates originated from rice and other gramineous hosts were tested. Seventeen including rice and non-rice isolates formed appressoria on hydrophobic surface, but none of isolates formed appressoria on hydrophilic surface. Eighteen isolates formed appressoria on hydrophilic surface in the presence of IBMX, an inhibitor of phosphodiesterase, except two rice isolates. These results strongly support the hypothesis that appressorium formation by M. grisea is induced by hydrophobic hard surface and regulated by the endogenous level of cAMP in the cells. Understanding fungal development is not only of biological interest but provides new targets for novel disease control strategies.