外源Ca^2＋对离体菠菜叶片衰老的影响

以叶绿素、蛋白质含量为衰老指标,研究了Ca~(2+)在离体菠菜叶片衰老过程的效应。同时,采用同位素示踪技术研究了光照对离体菠菜叶片吸收,累积Ca~(2+)的影响;实验结果表明,0—10mmol/L Ca~(2+)能使菠菜叶片维持较高含量的叶绿素及各种蛋白质组分。在光、暗条件下,叶片均能吸收外源Ca~(2+),而光照能促进叶片对Ca~(2+)的吸收,暗处理3天的叶片,尚能在分离的叶绿体组分中发现~(45)Ca~(2+),占叶片总放射强度的0.5%。

EFFECTS OF E OGENOUS Ca~(2+) ON SENESCENCE OF DETACHED SPINACH LEAVES

Effects of exogenous Ca~(2+) on content of chlorophylls and proteins during the senescence of detached spinach leaves were studied: at the same time, the relation between accumulate of exogenous Ca~(2+) in the detached leaves and light treatment was analysed with isotopic tracer technique. The results showed that treatment of 0-10mmol/L Ca~(2+) at 7-day-dark made content of the chlorophylls and the proteins keep up and that the leaves can absorb Ca~(2+) at the light as well as at the darkness, and the light promoted clearly accumulate of ~(45)Ca~(2+) in the leaves, meanwhile, at 3-day-dark-treatment, a radioactive calcium can be determined in the chloroplast fraction.