盐胁迫对葡萄砧木‘3309C’叶片光抑制的影响

探讨氯化钠盐胁迫对葡萄砧木‘3309C’叶片光系统Ⅰ(PSI)和光系统Ⅱ(PSII)活性的影响,为滨海盐碱地葡萄栽培提供理论参考。以1年生葡萄砧木‘3309C’为试材,通过同时测定葡萄叶片叶绿素荧光快速诱导动力学曲线和P700+再还原动力学曲线,结合叶绿素荧光淬灭分析,探讨了持续盐胁迫(100 mmol/L)对葡萄砧木叶片PSI和PSII活性的影响。随着盐处理时间的延长,PSII最大光化学效率逐渐降低,PSII放氧复合体受破坏的程度和反应中心电子传递受阻程度均明显增大,最大荧光显著降低,盐胁迫导致葡萄叶片PSII与PSI间激发能分配严重偏离平衡,最大光氧化P700显著降低,且发生降低时间明显早于PSII最大光化学效率。P700+再还原动力学曲线分析表明持续盐胁迫下葡萄叶片P700⁺再还原半衰期逐渐增大,环式电子传递受阻。持续盐胁迫导致葡萄砧木叶片2个光系统激发能分配严重偏离平衡状态,抑制了光系统活性,更多的能量被用来进行热耗散,而围绕PSI的环式电子传递活性的降低则进一步加剧了葡萄叶片光系统的光抑制程度。

Effects of salt stress on photoinhibition of grape rootstock '3309C' leaves

To investigate the effects of sodium chloride stress on the photosystemⅠ(PSI)and photosystemⅡ(PSII)activities of grape rootstock’3309C’,and provide a theoretical reference for viticulture in coastal saline-alkali soil.Using the annual grape rootstock’3309C’as the test material,the chlorophyll fluorescence fast induction kinetic curve and the P700^+reductive kinetic curve were simultaneously determined by grape chlorophyll fluorescence quenching analysis.The effects of continuous salt stress(100 mmol/L)on PSI and PSII activities in grape rootstocks were studied.With the prolongation of salt treatment time,the maximum photochemical efficiency of PSII decreased gradually,the degree of damage of PSII oxygen release complex and the electron transfer resistance of reaction center increased significantly.Salt stress caused PSII of grape leaves.The excitation energy distribution with PSI is seriously deviated from equilibrium,the maximum photooxidation P700 is significantly reduced,and the Pm reduction time is significantly earlier than the maximum photochemical efficiency of PSII decreased gradually.The P700^+re-reduction kinetic curve analysis showed that the P700^+re-reduction half-life of grape leaves increased gradually under continuous salt stress.Sustained salt stress caused the excitation energy distribution of the two photosystems of grape rootstock leaves to deviate from equilibrium,inhibiting the activity of photosystem,more energy was used for heat dissipation,and the decrease of circular electron transport activity around PSI was further aggravated.The degree of light inhibition of the grape leaf light system.