水分胁迫使刺槐实生苗核糖核酸酶活力增加原因的探讨

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

水分胁迫能促使刺槐(Robinia pseudoacacia)实生苗核糖核酸酶(RNase)活力增加。与此同时,水分胁迫的刺槐实生苗叶片中Al、Cd、Co、Cr、Fe、Li、Mn、Na、Ti和V含量(×10^(-6)(ppm)》比对照增加,Ba、Ca、Ni、P和Sr含量比对照稍减少,而K、Cu、Mg、Pb和Zn含量不变。亚胺环己酮(CHM)前处理对充分供水和水分胁迫的刺槐实生苗RNase活力增加均有强烈的抑制作用。水分胁迫可导致~3H-亮氨酸参入刺槐实生苗RNase能力明显减小,而胁迫实生苗的RNase活力则比充分供水的对照高13％,从而证明水分胁迫时刺槐实生苗RNase活力增加主要是由于RNase重新合成所致。

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.