淹水胁迫下水稻根尖细胞中Ca^2＋和Ca^2＋—ATP酶的分布

应用电镜细胞化学方法，对淹水胁迫下水稻根尖细胞中Ca^2 和Ca^2 -ATP酶分布的变化进行了观察。正常生长条件下，Ca^2 主要分布于液泡和细胞间隙中，而细胞质基质、细胞核中分布很少；Ca^2 －ATP酶主要分布于质膜上，线粒体膜、内质网膜、核膜上也有酶分布。经过没顶淹水处理后，液泡、细胞间隙中的Ca^2 沉淀颗粒明显减少，而胞质及核基质中的沉淀颗粒明显增多，同时，质膜及其他膜结构上Ca^2 －ATP酶的活性明显降低。淹水造成根尖细胞中Ca^2 －ATP酶活性降低，胞质和核基质中Ca^2 积累，将影响细胞的正常生理代谢活动。

Distribution of Ca~(2 ) and Ca~(2 ) ATPase in Root Apical Cells of Rice under Submergence Stress

Changes of Ca 2 and Ca 2 ATPase distribution in root apical cells of rice under submergence stress were determined by cytochemical methods. Grown under normal environment, Ca 2 mainly distributed in vacuoles and intercellular space, and there was little Ca 2 in matrix of cytoplasm and nucleus. Moreover, Ca 2 ATPase was demonstrated on plasma membrane, as well as on membrane of endoplasmic reticulum, mitochondria and nucleus. Alternatively, the distribution of Ca 2 and Ca 2 ATPase changed obviously under submergence stress. The Ca 2 in vacuoles and intercellular space decreased and it deposited in matrix of cytoplasm and nucleus. On the other hand, the viability of Ca 2 ATPase on plasma membrane and other membrane decreased. This distributing change of Ca 2 and Ca 2 ATPase could be one of the reasons that induce roots to be destroyed under submergence stress.