The RNase of leaves of resistant and susceptible barley cultivars after infection with leaf rust ( Puccinia hordei Otth.)

Abstract

The changes induced in the RNase of barley leaves ( Hordeum vulgare L.) by infection with barley leaf rust ( Puccinia hordei Otth.) have been examined. In the incompatible interaction between the barley cultivar Triumph and rust isolate 65, the RNase of the infected tissue resembles that of the healthy tissue. For the compatible interaction between the barley cultivar Zephyr and rust isolate PS, the RNase isolated 8 days after infection differs both from the enzyme of healthy tissue and the enzyme from germinated rust spores in its kinetic properties, temperature sensitivity, substrate specificity and sensitivity to inhibitors. These observations are consistent with the behaviour of the enzyme in other host-biotrophic fungus interactions.