光谱分析和延迟荧光检测研究外源水杨酸对拟南芥光合作用的影响

外源水杨酸在影响植物活性氧代谢以及光合作用等方面起着重要作用.该文以野生型拟南芥和胁迫条件下内源水杨酸含量较高的cpr5突变体和内源水杨酸含量较低的eds-4突变体为材料,采用光谱分析和延迟荧光检测分析手段,研究了不同浓度的外源水杨酸对三种拟南芥离体叶片光合能力的影响,实验发现100和300 μmol·L-1较低浓度的外源水杨酸对野生型拟南芥离体叶片,eds-4叶片的光合作用都有一定的促进作用,而对cpr5叶片的光合会产生抑制,形成一种胁迫.500μmol·L-1较高浓度的外源水杨酸对三种拟南芥离体叶片均形成了一种胁迫,进而阻抑和降低了叶片的光合效能.DCF(dichloro fluorescein)标记活性氧检测了外源水杨酸作用下叶片活性氧产生量的变化,发现在500μmol·L-1外源水杨酸作用下60min内叶片组织中活性氧产生了明显的积累.

Effects of Exogenous Salicylic Acid on Photosynthesis in Arabidopsis Leaves Based on Fluorescence Spectra and Delayed Fluorescence Technique

Salicylic acid plays an important role in the active oxygen metabolism and the photosynthesis of the plant. Wild type Arabidopsis thaliana (ecotype Columbia) and it’s two different mutants were used as experimental material: one is the cpr5 mutant which has an abundant endogenesis SA level under stress conditions, and the other is the eds-4 mutant which has a lacking endogenesis SA level under stress conditions. The leaves of those three different Arabidopsis were treated with 100, 300, and 500 μmol·L-1 concentrations of salicylic acid, respectively. The fluorescence emission spectra and the delayed fluorescence were detected respectively. The authors found that there was a slight elevation in the photosynthetic efficiency of PSⅡof the WT and eds-4 leaves with 100 and 300 μmol·L-1 SA treatment. However, there was a decrease in the photosynthetic efficiency and even a stress of the cpr5 leaves with 100 and 300 μmol·L-1 SA treatment. It was also showed that there came to be an obvious stress of the leaves of all three different kinds of Arabidopsis with 500 μmol·L-1 SA treatment and the photosynthetic efficiency of them decreases sharply. The generation of active oxygen was also detected with the DCF labeling under 500 μmol·L-1 SA treatment. The authors found that there was an obvious accumulation of active oxygen along with the time under SA treatment.