变温条件下钙对山定子叶片氮代谢的影响

Effect of Calcium on Nitrogen Metabolism of Malus baccata Borkh. Leaves under Changing Temperature

以当年生山定子实生苗为试材,研究变温(5℃→20℃→10℃→0℃)条件下添加钙盐(2%CaCl_2和1%CaAc_2)和钙抑制剂(20mmol·L^(-1)EGTA和0.1 mg·L^(-1)LaCl_3)对山定子叶片氮代谢关键酶活性和可溶性蛋白含量变化的影响。结果表明,变温处理导致硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性先降低后升高,谷氨酸合酶(GOGAT)活性呈降低趋势,可溶性蛋白含量变化较平缓。添加钙盐处理不同程度上提高了氮代谢关键酶酶活性和可溶性蛋白含量,其中有机钙处理的效果更显著。两种钙抑制剂EGTA和LaCl_3处理的效果有所不同,其中EGTA处理的NR和GS活性在升温阶段低于对照,在降温阶段高于对照,对GOGAT活性一直起抑制作用,且降低了可溶性蛋白含量。而LaCl_3处理能够不同程度诱导各酶活性的表达,并且能够提高可溶性蛋白含量。本研究的结果对冷凉地区苹果钙素营养管理提供了理论参考。

This study using seedling of Malus baccata Borkh. as material,setting variable temperature treatment （5℃→20℃→10℃→0℃）, combined with application of calcium compounds （2% CaCl2 and 1% CaAc2）and Ca2^＋ chelator（EGTA）, Ca2^＋ channel blocker （LaCl3）to study the process of substantial change temperature,the regulatory role of Ca2^＋ on nitrogen metabolism of Malus baceata Borkh. seedling leaves. The results as follows： changing temperature induced NR and GS activities increase first and then decrease, and GOGAT activity was decreased. Different calcium salts treatment can improve the key enzyme activities in nitrogen metabolism and the soluble protein content,the effect of 1% CaAc2 treatment was more significant. The effect of EGTA and LaCl3 treatment is different. The NR and GS activity under EGTA treatment were lower than that under the control in the temperature rise period,and were higher than control in the cooling stage,the activity of GOGAT was inhibited,and the soluble protein content was decreased. While LaCl3 treatment can induce the expression of the enzyme activity in different degree,and can increase the content of soluble protein. This study provide theoretical reference for Ca nutrition management of apple in cool