钙对亚高温下番茄幼苗叶片光合的调控作用

 【目的】分析不同浓度CaCl2及钙作用抑制剂EGTA(钙螯合剂)与TFP（钙调素抑制剂）对亚高温下番茄叶片光合作用及PS Ⅱ与PS Ⅰ荧光参数的影响,探讨钙对亚高温下番茄叶片光合作用的调控机制。【方法】以‘辽园多丽’番茄幼苗为试材,通过0、10、30 mg?L-1的CaCl2预处理,筛选出防止亚高温逆境障碍的适宜CaCl2浓度,进而通过喷施CaCl2及其作用抑制剂（EGTA与TFP）预处理,探讨昼间35℃亚高温下钙对番茄叶片光合作用的调控作用。【结果】不同浓度CaCl2处理均对亚高温下番茄叶片的净光合速率有提高作用,其中10 mg?L-1CaCl2处理效果最显著;CaCl2处理显著提高了亚高温逆境下叶片PS Ⅱ的最大光化学效率（FPSII）,显著提高了PS Ⅱ与PS Ⅰ的量子产量［Y(Ⅱ)与Y(I)］,提高了由于供体侧限制引起的PS I处非光化学能量耗散的量子产量［Y(ND)］,降低了由于受体侧限制引起的PS I处非光化学能量耗散的量子产量［Y(NA)］,而EGTA与TFP则起到一定负调控作用。【结论】喷施10 mg?L-1CaCl2 能够有效提高亚高温下番茄叶片光合作用,钙对于维持气孔的正常开闭及保护PSⅡ与PSⅠ活性均具有重要调控作用。

Regulation of Calcium on Photosynthesis of Tomato Leaves Under Sub-High Temperature Stress

【Objective】In order to reveal the regulation function of calcium on photosynthesis of tomato leaves under sub-high temperature stress, the effects of CaCl2 on photosynthesis and fluorescence of PS Ⅱand PS Ⅰ under sub-high temperature stress were studied. 【Method】In order to select a appropriate concentration, the tomatoes grown in greenhouse were pretreated with 0, 10 and 30 mg?L-1CaCl2 during the period of sub-high temperature, and then photosynthesis, chlorophyll fluorescence of PS Ⅱand PS Ⅰ were analyzed for the tomatoes pretreated with CaCl2, with the appropriate concentration, Ca2+ chelator EGTA and CaM antagonist TFP. 【Result】 The net photosynthetic rate(Pn) increased at three concentrations of CaCl2 treatments under sub-high temperature stress, especially in the treatment of 10 mg?L-1CaCl2. Under sub-high temperature stress, the maximal photochemical efficiency (FPSII) of PS Ⅱ, photochemical quantum yield of PS Ⅱ and PS Ⅰ[Y(Ⅱ) and Y(Ⅰ)], quantum yield of non-photochemical energy dissipation in PS I due to donor side limitation [Y(ND)] in the tomato leaves pretreated with CaCl2 were much higher than that of control, while quantum yield of non-photochemical energy dissipation in PS I due to acceptor side limitation [Y(NA)] was much less than that of the control. EGTA and TFP treatments had negative effect.【Conclusion】The treatment of 10 mg?L-1 CaCl2 could improve photosynthesis of tomato leaves under sub-high temperature stress. And calcium played an important role in regulating stomatal movements and protecting PS Ⅰ PS Ⅱ not to be injured.