光和激素在叶片衰老中的作用  

THE EFFECT OF LIGHT AND HORMONES ON LEAF SENESCENCE

作　　者：李晓萍[1] 胡文玉[2] 

机构地区：[1]中国科学院华南植物研究所,广州五山510650 [2]沈阳农业大学基础部,沈阳110161

出　　处：《Acta Botanica Sinica》1990年第12期957-965,共9页Acta Botanica Sinica（植物学报：英文版）

摘　　要：研究了小麦叶片在光、暗、不同照光时间以及外源 KT 和 ABA 影响下衰老过程中超氧化物歧化酶(SOD),脂质过氧化产物丙二醛(MDA)含量及细胞膜透性的变化。并研究了菠菜叶绿体在光、暗下老化时叶绿素降解、脂质过氧化和内部结构的变化。结果表明,叶片在光下衰老时,SOD 活性先增加而后下降,活性的增加可能有新的酶蛋白合成;光虽然可明显延缓叶片衰老,但延长照光时间则促进脂质过氧化,加速叶片的衰老;外源激素通过调节 SOD 活性,控制脂质过氧化,从而延缓或促进叶片衰老;叶绿体在光下衰老时的色素降解和脂质过氧化有包括 O在内的自由基参与。光对维持离体叶绿体的结构有积极作用。With wheat leaves as material,the changes of superoxide dismutase(SOD),lipid peroxi- dation and membrane permeability during leaf senescence in light or dark,and treated with phytohormones(KT or ABA)have been studied.The changes of chlorophyll content,lipid peroxidation and fine structure of spinach chloroplasts senescing in light or dark have also been studied.When leaves senesce in light,the activity of SOD increased at first then decreas- ed.The increase of SOD activity was able to result from the synthesis of new protein.Light was found to delay the leaf senescence obviously but also accelerate leaf senescence by causing lipid peroxidation when prolonged the illumination time.The delay or acceleration of leaf senescence by exogenous hormones were observed,it may be due to the control of lipid peroxi- dation by adjusting the activity of SOD.Oparticipated the chlorophyll decomposition and lipid peroxidation during chloroplasts senesce in light.A favourable role of light in mainta- ing the fine structure of isolated chloroplasts was clear.

关 键 词：叶片衰老 光 激素 

分 类 号：Q945.48[生物学—植物学]