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.
出处
《林业科学》
EI
CAS
CSCD
北大核心
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
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
Festuca arundinacea
high temperature stress
photosynthesis
chlorophyll fluorescence
absorbed light allocation