Suppression of the Activation of Chitinase and β-1, 3-Glucanase in Pea Epicotyls by Orthovanadate and a Suppressor from Mycosphaerella pinodes

Abstract

A pea pathogen, Mycosphaerella pinodes, secretes both an elicitor and a suppressor in its pycnospore germination fluid. The effects of the elicitor, the suppressor and orthovanadate, an inhibitor of P-type ATPase, on the activation of pathogenesis-related proteins such as endochitinase and β-1, 3-glucanase were examined. The elicitor induced the activation of these enzymes in pea, soybean and kidney bean. Such activation in 3 plant species tested was suppressed by the concomitant presence of 1mM orthovanadate with the elicitor. The suppressor, however, suppressed the activation in only pea plants but did not in nonhost plants of M. pinodes. These results suggest that the inhibition of the ATPase in plasma membranes highly correlates to the suppression of the activation of endochitinase and β-1, 3-glucanase.