不同叶龄拟南芥叶片中STN7激酶表达的研究

The expression of STN7 in different old weeks leaves in Arabidopsis thaliana

光合生物的状态转换可以调节激发能在2个光系统间的分配,以响应环境变化,避免光对其产生损伤.状态转换过程中伴随着LHCⅡ蛋白的磷酸化与去磷酸化.拟南芥STN7蛋白激酶参与了LHCⅡ蛋白的磷酸化和状态转换过程.借助STN7抗体与磷酸化苏氨酸抗体,研究了光照3h时STN7激酶在不同叶龄拟南芥叶片中的表达与LHCⅡ蛋白磷酸化的关系.实验结果表明,随着拟南芥叶龄的增加,STN7激酶蛋白的稳态水平逐渐降低,而LHCⅡ蛋白磷酸化与叶片PSⅡ光合活力则在生长6w时为最大.说明STN7激酶的调节存在酶量与酶活性的调节,并且以后者为主.

State transitions can regulate the distribution between the two photosystems, thus adapting to environmental changes. The process of state transitions is accompanied by phosphorylation and dephos- phorylation of LHC Ⅱ. was studied the relationship between the expression of STN7 at protein level and the LHC Ⅱ phosphorylation level by SNT7 antibody and P-Thr antibody in the thylakoid membranes isolated from 4, 6 and 8 weeks old Arabidopsis leaves after illumination for 3h. The results showed that the steady state level of STN7 protein was down regulated with increasing of leaf ages. LHC Ⅱ proteins achieved the maximal phosphorylation level in the 6 weeks old leaves and the photosynthesis activity was higher in the 6 weeks old leaves than in the 4 or 8 weeks old leaves. This suggested that the regulation of STN7 expression was at the enzyme quantity level and the enzyme activity level, especially the latter