长期高温胁迫对高羊茅光合特性和抗氧化酶活性的影响  

Effects of Long-term High Temperature Stress on Photosynthetic Characteristics and Antioxidant Activity in Festuca arundinacea

作　　者：金松恒[1] 徐礼根[2] 李雪芹[3] 王俊刚[1] 朱澜[1] 贾晓琳[1] 

机构地区：[1]浙江林学院林业与生物技术学院,临安311300 [2]浙江大学生命科学学院,杭州310058 [3]浙江林学院天目学院,临安311300

出　　处：《林业科学》2009年第3期155-159,共5页Scientia Silvae Sinicae

基　　金：浙江省科技计划项目(2003C30017;2004C13001)资助;浙江林学院科研启动基金(2351000725)资助

摘　　要：In this study,the gas exchange,chlorophyll fluorescence and antioxidant activity in tall fescue cultivar,Houndog 5 ,were investigated under long-term high temperature stress. The results showed that the net photosynthetic rate (Pn),chlorophyll content,apparent quantum yield (AQY),the maximum carboxylation rate of Rubisco (V c,max ),the maximum rate of RuBP regeneration (J max ) and carboylation efficiency (CE) were significantly decreased after treatment with high temperature for 30 d. High temperature also decreased the efficiency of excitation capture by open PSⅡ reaction centers (F’v/F’m) and the proportion of open PSII reaction centers,thereby resulting in an increased electron transport flow (ETR). The non-photochemical quenching (NPQ) and energy-dependent quenching (qE) of the tall fescue were significantly decreased,and the excess energy of PSII reaction centers (Ex) was largely increased after long-term high temperature stress. Moreover,high temperature stress significantly decreased the SOD,POD,APX and GR activities,and increased the MDA content. These results indicated that the mechanism of excitation energy dissipation and antioxidant systems were injured,so that the excessive excitation energy could not be dissipated and reactive oxygen species could not be scavenged efficiently.In this study, the gas exchange, chlorophyll fluorescence and antioxidant activity in tall fescue cultivar, Houndog 5, were investigated under long-term high temperature stress. The results showed that the net photosynthetic rate （Pn）, chlorophyll content, apparent quantum yield （AQY）, the maximum carboxylation rate of Rubisco （Vc,max）, the maximum rate of RuBP regeneration （ Jmax ） and carboylation efficiency （CE） were significantly decreased after treatment with high temperature for 30 d. High temperature also decreased the efficiency of excitation capture by open PS 1T reaction centers （F＇v/F＇m） and the proportion of open PSII reaction centers, thereby resulting in an increased electron transport flow （ETR）. The non-photochemical quenching （NPQ） and energy-dependent quenching （qE） of the tall fescue were significantly decreased, and the excess energy of PSII reaction centers （ Ex ） was largely increased after long-term high temperature stress. Moreover, high temperature stress significantly decreased the SOD, POD, APX and GR activities, and increased the MDA content. These results indicated that the mechanism of excitation energy dissipation and antioxidant systems were injured, so that the excessive excitation energy could not be dissipated and reactive oxygen species could not be scavenged efficiently.

关 键 词：高羊茅 高温胁迫 光合作用 叶绿素荧光 吸收光能分配 

分 类 号：Q945.11[生物学—植物学]