Abstract
Apoplastic space is the first place to meet plant pathogens where hydrolytic enzymes from pathogens are secreted to degrade host cell walls. Against degradation of cell walls plants produce inhibitor proteins such as xylogluan-specific endoglucanase inhibitor proteins and polygalacturonase inhibitor proteins. These proteins are proposed to form the complex with hydrolytic enzymes to inhibit hydrolytic activities and trigger the signal transduction. Specificity, ability of inhibiting hydrolytic activities and involvement in plant defense responses for the inhibitor proteins must be elucidated in details. Endo-1,3-1,4-beta-glucanase (MoCel12A) from Magnaporthe oryzae that belongs to glycosyl hydrolase family 12 and specifically hydrolyzes beta-1,3-1,4-glucan induced hypersensitive response (HR) cell death in Nicotiana benthamiana and Arabidopsis thaliana. The elicitation appears to be triggered by the recognition of MoCel12A but not by the hydrolyzed fragments of cell walls. In this presentation we demonstrate the identification and characterization of a binding protein to MoCel12A, and discuss the involvement of MoCel12A and a binding protein in HR-like cell death.
