水稻叶片自然衰老过程中Rubisco大亚基的含量变化  

Changes in Relative Content of Rubisco Large Subunit in Naturally Senescing Rice Leaves

作　　者：李瑞[1] 周玮[1] 李丽[1] 陆巍[1] 

机构地区：[1]南京农业大学生命科学学院植物科学系,江苏南京210095

出　　处：《中国水稻科学》2009年第5期555-558,共4页Chinese Journal of Rice Science

基　　金：南京农业大学科技创新基金资助项目(Y200523)

摘　　要：以水稻低叶绿素b突变体及其野生型(镇恢249)为材料,研究了水稻第5叶叶片自然衰老过程中光合放氧、Rubisco大亚基含量变化以及对胰蛋白酶敏感性的变化,并通过喷施不同的抗氧化剂以及氧化剂研究其对Rubisco大亚基含量变化的影响。结果表明,叶片全展后随着衰老进程,突变体与野生型光合放氧速率、Rubisco大亚基相对含量呈下降趋势,抗氧化剂可以不同程度地缓解Rubisco大亚基含量的下降,而氧化剂则加速Rubisco大亚基含量的下降。低叶绿素b突变体的光合放氧速率高于野生型,Rubisco大亚基含量下降慢于野生型,并且衰老进程中突变体Rubisco大亚基对胰蛋白酶的敏感性低于野生型,推测活性氧是Rubisco降解的调节剂之一。A rice mutant with low chlorophyll b and its wild type rice were adopted to investigate the changes in photosynthetic oxygen evolution rate, and content and sensitivity to trypsin proteolysis of Rubisco large subunit （LSU） during leaf senescence, as well as the effects of antioxidant and oxidant on changes in relative content of Rubisco LSU. The results showed that after full expansion of leaves in the mutant and its wild type plants, oxygen evolution and relative content of Rubisco LSU declined significantly. The degradation of Rubisco LSU could be retarded by antioxidants （reduced glutathione and ascorbic acid） but accelerated by oxidants （oxidized glutathione and H2O2 ）. The oxygen evolution rate in the mutant was higher than that in the wild type. On the contrary, the degradation of Rubisco LSU was slower in the mutant than in the wild type as leaf senescence. Lower sensitivity to trypsin proteolysis of Rubisco LSU was found in the mutant in comparison with the wild type. It is suggested that reactive oxygen species （ROS） mediate the degradation of Rubisco LSU.

关 键 词：水稻 叶绿素B 突变体 衰老 光合放氧 1 5-二磷酸核酮糖羧化酶/加氧酶 

分 类 号：S511[农业科学—作物学]