摘要
黄瓜子叶在低温光照下处理时,随着时间的延长,Chl含量和CAT活性显著下降,POD和AsA-POD在开始24h活性亦有下降趋势,随后POD活性显著增加,而AsA-POD活性仅稍有提高。Chl含量的减少和CAT活性降低之间呈正相关,与POD活性的增加呈负相关。低温、光照处理的黄瓜子叶内Chl的降低可被亚胺环己酮(CHM)延缓,被AsA、Vit E、没食子酸丙酯(PG)和DCMU抑制,但被H_2O_2,乙醇酸钠和甲基紫精(MV)加速。
The changes of chlorophyll content and the activities of peroxidase, catalase and ascorbate peroxidase in cucumber cotyledons under chilling in the light were investigated to explore the relationship between chlorophyll degradation and enzymatic reaction. When cucumber seedlings were exposed to chilling and light, it was observed that chlorophyll content and catalase activity decreased markedly with the time (Fig. 1, 3), the activities of peroxidase and ascorbate peroxidase decreased during the first 24 hours, then peroxidase activity increased markedly, while ascorbate peroxidase activity increased only sightly (Fig. 2).The degradation of chlorophyll in cucumber cotyledons exposed to chilling and light was positively correlated to the decrease of catalase activity (Fig. 3), and negatively correlated to the increase of peroxidase activity (Fig. 2). By using protein synthesis inhibitor and some other chemical agents, it was found that chlorophyll degradation of cucumber cotyledons was retarded by cycloheximide (CHM) (Table 1) and inhibited by ascorbate (AsA), [3-(3, 4-dichlorophenyl)-1, 1-dimethylurea] (DCMU), α-tocopherol (Vit E) and propyl gallate (PG) (Fig, 4, 5), but promoted by H_2O_2, sodium glycolate and methyl viologen (MV). It was suggested that peroxidase-H_2O_2 system may participate in the course of chlorophyll degradation in cucumber cotyledons under chilling in the light.
基金
国家自然科学基金
关键词
黄瓜
低温
光照
叶绿素
酶促反应
chilling and light, chlorophyll, peroxidase
catalase
ascorbate peroxidase
cucumber cotyledons
