| The Proteinase and RNase activities in wheat leaves of both drought-resistant.(Changwu 131). and drought-sensitive (zhengyin 1) variety increased during water stress, which content of soluble protein, insoluble protein and RNA decreased. The increment in prroteinase and RNase activity and.the decrement in Protein and RNA content in the drought-resistant variety were lower than in the drought-sensitive one. Treatment with exogenous spermine could delay the increase in enzyme activity and the decrease in protein and RNA content, and treatment with exogenous spermine could retard drought-sensitive variety senescence better than drought-resistant one under water stress. |