The Research on RNase Activity Increasing Reason in Black Locust Seedling Results from Water Stress

RNase activity in the seedling of Black Locust increased remarkably under water stress. The while, Al, Cd, Co, Cr, Fe, Li, Mn, Na, Ti and V ions contents in water-stressed leaves of Black Locust seedling rose as compared with the control, Ba, Ca, Ni and Sr contents slightly decreased, and there were no changes in K, Cu, Mg, Pb and Zn contents. Pretreatment of the Black Locust seedlings with cycloheximid (30 ppm) for 24 h. before dehydration completely prevented the increase of RNase activity due to water stress. Partly purification of 3H-leucine-labelled RNase from control and water-stressed Black Locust seedlings revealed that incorporation of 3H-leucine into the RNase of water-stressed seedlings was markedly decreased, and activity of RNase from water-stressed seedlings was enhanced by 13% as compared to with the control. It implies that an increase in activity of RNase from water-stressed seedlings was mainly due to its fresh synthesis.