钙对杂交水稻离体叶片衰老的影响

Effects of Calcium on Senescence in Detached Leaves of Hybrid Rice

以叶绿素和蛋白质的质量分数下降作为衰老的生理指标，研究了Ｃａ２＋和Ｃａ２＋的螯合剂ＥＤＴＡ对杂交水稻离体叶片衰老的作用．结果表明，Ｃａ２＋能延缓杂交水稻离体叶片中叶绿素和蛋白质的质量分数的下降，提高超氧化物歧化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）、抗坏血酸过氧化物酶（ＡｓＡ－ＰＯＤ）和谷胱甘肽还原酶（ＧＲ）的酶活性；增加抗坏血酸（ＡｓＡ）和谷胱甘肽（ＧＳＨ）的的质量分数；降低膜脂过氧化产物丙二醛（ＭＤＡ）的质量摩尔浓度．１～２０ｍｍｏｌ／ＬＥＤＴＡ降低叶片中叶绿素和可溶性蛋白质的质量分数；降低ＡｓＡ－ＰＯＤ和ＣＡＴ的酶活性；降低ＡｓＡ、ＧＳＨ的质量分数；提高ＳＯＤ酶活性，但对ＧＲ酶活性的影响不大．外加Ｃａ２＋可使ＥＤＴＡ的抑制作用减轻．

Effects of Ca 2+ and Ca 2+ +EDTA on senescence in detached leaves of hybrid rice were studied using contents of chlorophyll and soluble protein as the physiological indexes. The results show that Ca 2+ could slow down the loss of chlorophyll and soluble protein, increase the activities of superoxide dismutase(SOD),catalase (CAT),ascorbic acid peroxidase (AsA POD) and glutathione reductase(GR), and raise the contents of ascorbic acid(AsA) and glutathione(GSH),and decrease malondialdehyde(MDA) content. The activities of AsA POD and CAT, and the contents of chlorophyll, soluble protein, AsA and GSH reduced by 1～20 mmol/L EDTA.In the meantime, the activity of SOD increased, and GR activity was less affected. External Ca 2+ could weaken the effect of EDTA, and effect of 1 mmol/L Ca 2+ was larger than that of 0 1 mmol/L Ca 2+ .