乙烯诱导衰老过程中大豆叶片快速叶绿素荧光诱导动力学和PSⅡ光化学特征  

Characteristics of PSⅡ Photochemistry and Chlorophyll a Fluorescence Transient During Senescence of Soybean Leaves Induced by Ethylene

作　　者：吴锡冬[1] 代金明[2] 孙宁[1] 李鹏民[2] 高辉远[2] 

机构地区：[1]天津农学院农学系,天津303840 [2]山东农业大学生命科学学院,山东泰安271018

出　　处：《天津师范大学学报（自然科学版）》2006年第1期28-32,共5页Journal of Tianjin Normal University：Natural Science Edition

基　　金：天津市科技攻关项目(043123411)

摘　　要：通过分析光合速率和快速叶绿素荧光诱导动力学曲线,研究了乙烯诱导衰老过程中大豆叶片PSⅡ光化学特征的变化.随着大豆叶片的衰老,光合速率大幅度下降,但是Fv/Fm只有轻微下降.这表明,大豆衰老过程中光合速率的下降不是PSⅡ光化学活性下降造成的;随着衰老,光合机构中的QB降解,QB的降解可能是导致PSⅡ光化学活性下降的关键因素.叶绿素荧光猝灭分析表明,在衰老初期,非光化学猝灭NPQ是强光下耗散过剩激发能的一个重要机制,然而当叶片严重衰老时,PSⅡ反应中心的失活可能成为光合机构耗散过剩激发能的另一种有效机制.By analyzing the photosynthesis, fluorescence transient and chlorophyll a fluorescence quenching, the characteristics of PS Ⅱ photochemistry leaves during senescence of soybean induced by ethylene was investigated. Along with the senescence, Pn decreased dramatically, however, only slight decrease in Fv/Fm was observed, which indicates that the decline of Pn was not caused by the decrease of PS H activity during senescence. With senescence, QB protein was degraded, which may be the key factor of PS Ⅱ activity declining. By analysis of Ch1 fluorescence quenching, it was demonstrated that at the beginning of senescence non-photochemical quench （NPQ） was an important mechanism to dissipate extra excitation energy under high light, whereas, inactivation of reaction centers might be an ahernative mechanism to dissipate extra excitation energy when leaves became severely senescent.

关 键 词：乙烯 叶绿素荧光诱导动力学 非光化学猝灭 PSⅡ反应中心失活 热耗散 

分 类 号：Q945[生物学—植物学]