Elicitation of ß-l,3-Glucanase and Chitinase Activities in Cell Suspension Cultures of Ascochyta rabiei Resistant and Susceptible Cultivars of Chickpea ( Cicer avietinum)

ß-1,3-Glucanase and chitinase activities have been analyzed in cell suspension cultures o f an Ascochyta rabiei resistant ILC 3279 and a susceptible ILC 1929 cultivar o f chickpea ( Cicer arietinum) following treatment with an elicitor derived from this fungal pathogen. A facile method to determine both hydrolase activities in the cell culture medium was established. Significantly higher constitutive and elicitor-induced levels o f both hydrolase activities were found in the medium o f the ILC 3279 cell culture. The release o f these enzyme activities is not due to cell lysis, but rather the consequence o f a secretion mechanism. The cells o f the resistant line contained a 5 times higher level o f chitinase activity in comparison to the ILC 1929 cell culture, whereas the latter cells possessed a 3 times higher ß-1,3-glucanase activity. The results are interpreted that accumulation o f extracellular hydrolase activities may play an important role among the various plant defense mechanisms previously determined for the incompatible interaction between the resistant cultivar and its fungal pathogen.