钙对亚高温下番茄幼苗叶片光合作用的调控作用

摘要

[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 Ⅱ and 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 Ⅱ and 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.%[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10mg·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(FPS11),显著提高了Ps Ⅱ与PSⅠ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Ps Ⅰ活性均具有重要调控作用.