杨程, 李向东, 杜思梦, 张德奇, 时艳华, 王汉芳, 邵运辉, 方保停, 程红建, 位芳. 高温对冬小麦旗叶光合机构的伤害机制[J]. 中国生态农业学报 (中英文), 2022, 30(3): 399−408. DOI: 10.12357/cjea.20210469
引用本文: 杨程, 李向东, 杜思梦, 张德奇, 时艳华, 王汉芳, 邵运辉, 方保停, 程红建, 位芳. 高温对冬小麦旗叶光合机构的伤害机制[J]. 中国生态农业学报 (中英文), 2022, 30(3): 399−408. DOI: 10.12357/cjea.20210469
YANG C, LI X D, DU S M, ZHANG D Q, SHI Y H, WANG H F, SHAO Y H, FANG B T, CHENG H J, WEI F. Photosystem damage mechanism in flag leaves of winter wheat under high temperature[J]. Chinese Journal of Eco-Agriculture, 2022, 30(3): 399−408. DOI: 10.12357/cjea.20210469
Citation: YANG C, LI X D, DU S M, ZHANG D Q, SHI Y H, WANG H F, SHAO Y H, FANG B T, CHENG H J, WEI F. Photosystem damage mechanism in flag leaves of winter wheat under high temperature[J]. Chinese Journal of Eco-Agriculture, 2022, 30(3): 399−408. DOI: 10.12357/cjea.20210469

高温对冬小麦旗叶光合机构的伤害机制

Photosystem damage mechanism in flag leaves of winter wheat under high temperature

  • 摘要: 高温胁迫下小麦光合能力下降是影响小麦灌浆和导致产量下降的主要因素。探明高温对小麦旗叶光合机构的伤害机制有助于小麦高温抗性资源的合理利用。本研究选取35个河南省不同年代的主栽小麦品种, 在离体条件下采用快速叶绿素荧光、820 nm光反射、延迟荧光同步测定的方法, 对不同温度(22 ℃, 30 ℃, 38 ℃)处理下所有小麦品种光合电子传递活性相关参数进行了测定和分析。首先根据最大光化学效率(FV/FM)对高温的敏感程度将35个小麦品种分为高温不敏感(G1)和高温敏感(G2)两种类型, 然后对所测参数分别平均, 结果显示高温胁迫下两种类型小麦品种光系统Ⅱ (PSⅡ)的光能捕获效率、吸收的光能推动电子传递到初级醌受体(QA)下游和光系统Ⅰ (PSⅠ)末端的效率、质体醌(PQ)库的再还原能力高温下均显著下降, 但G2小麦品种下降幅度更大; 两种类型小麦品种PSⅠ活性均不受影响, 但G2小麦品种PSⅠ供体侧电子传递活性下降幅度大于G1小麦品种。通过3种研究方法的相互补充和印证, 最终表明PSⅡ反应中心活性、PSⅡ光能的捕获和QA向下游传递电子的能力的差异是导致两种类型小麦品种光合电子传递活性差异的主要原因, PSⅡ供体侧和PSⅠ活性对小麦光系统Ⅱ高温抗性没有直接影响。该研究对未来冬小麦抗高温品种选育和栽培管理技术的创新提供了参考。

     

    Abstract: High temperatures are one of the main environmental stresses at the filling stage of winter wheat. The reduction in wheat photosynthesis caused by heat stress affects the filling of wheat and reduces grain yield. China is rich in wheat cultivars, and their photosynthetic sensitivity to high temperatures varies. Investigating the mechanism of high-temperature damage to the photosynthetic apparatus of wheat flag leaves can help to rationalize wheat high-temperature resistance resources. In this study, 35 wheat cultivars planted widely in Henan Province during different historical periods were selected. The parameters related to photosynthetic electron transfer of all wheat cultivars were measured and analyzed using fast chlorophyll fluorescence, 820 nm light reflection, and delayed fluorescence synchronization determination. First, according to the maximum photochemical efficiency (FV/FM) under high temperature, 35 wheat cultivars were divided into two groups: high-temperature insensitivity and high-temperature sensitivity, and the parameters measured for the two types of wheat cultivars were averaged. The results showed that J and I points of chlorophyll fluorescence induction curves were raised and the maximum quantum yield for primary photochemistry (φPO), quantum yield for electron transport (φEo), quantum yield for reduction of end electron acceptors at the PSⅠ acceptor side (φRo), and performance index (PIABS) were significantly reduced in the two types of wheat cultivars under high-temperature stress. Moreover, the rise and decrease extents of high-temperature sensitive type were greater than those of high-temperature insensitive type, indicating that the PSⅡ light energy capture efficiency, the efficiency of the absorbed light energy to drive electrons downstream of the primary electron quinone acceptor QA, its efficiency to the PSⅠ end, and the re-reduction ability of the PQ pool decreased more in the leaves of the sensitive wheat cultivars under high temperatures. There was no significant decrease in the maximum decrease slope of the 820 nm light reflection curve (VPSⅠ) in either types of wheat cultivars, and the maximum increase slope of the 820 nm light reflection curve (VPSⅡ-PSⅠ) in both types of wheat cultivars significantly decreased. Furthermore, the decline of VPSⅡ-PSⅠ in the high-temperature sensitive wheat cultivars was greater than in the insensitive ones, indicating that the PSⅠ activity was not affected and the donor side of PSⅠ had a greater extent of damage in the high-temperature sensitive wheat cultivars. Values of both characteristic points of the delayed fluorescence induction curves (I1 and I2) decreased. At the same time, I2/I1 increased significantly at high temperatures and increased even more in high-temperature sensitive wheat cultivars, indicating that PSⅡ activity decreased and the efficiency of PSⅠ donor-side electron transfer to the end of PSⅠ increased. Based on the complementarity and confirmation of the three research methods, it is concluded that the difference in PSⅡ reaction center activity, PSⅡ light energy capture, and electron transfer from the acceptor side of QA to PSⅠ downstream is the main reason for the difference in photosynthetic ability between two types of wheat cultivars under high temperature. The PSⅡ donor side and PSⅠ activity have no direct impact on the high-temperature resistance of wheat. The results of this study help understand the current status of high-temperature resistance of wheat cultivars in the Huanghuai wheat-planting area and provide references for the breeding selection of high-temperature-resistant cultivars and innovation in cultivation techniques.

     

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