水杨酸对高温强光胁迫下小麦叶绿体D1蛋白磷酸化及光合机构运转的影响

摘要

[目的]研究外源SA对高温强光胁迫下小麦叶片类囊体膜Dl蛋白磷酸化和光合机构运转的影响.[方法]用0.5 mmol/L水杨酸(SA)溶液预处理灌浆期小麦叶片,以水预处理为对照,将预处理植株进行高温强光[35℃,1600 μmol/(m<'2>·s)]胁迫,测定胁迫处理过程中小麦旗叶活性氧代谢、叶绿素荧光参数及D1蛋白的变化.[结果]SA预处理有效抑制了高温强光下D1蛋白的净降解,保持了较高的D1蛋白磷酸化水平,高效防护了高温强光所致的氧化损伤,维持较高的超氧化物岐化酶(SOD)和抗坏血酸过氧化物酶(APX)活性,维持了较高的通过PSⅡ电子传递速率(Fv/Fo)、PSⅡ原初光化学效率(Fv/Fm)、实际光化学效率(φPSⅡ)、光化学猝灭系数(qP).[结论]SA预处理明显减轻了高温强光胁迫对光合机构的损伤,保证了PSⅡ的正常运转.%[ Objective ] The aim was to study the effects of exogenous SA on the D1 protein phosphorylation and operation of photosynthetic apparatus of wheat leaf chloroplasts under high temperature and illumination stress. [ Method] Wheat leaves at grain -filling stage were sprayed with 0.5 mmol/L of SA or water ( as control) under high temperature and illumination stress [35 ℃, 1 600μmol/( m2· s) ] for various hours, the changes in active oxygen metabolism ,chlorophyll fluorescence parameters,relative amount of phosphorylated and nonphosphorylated D1 protein in thylakoid membranes were determined. [ Result ] The results showed that after the folia application of SA, the degradation of D1 protein reduced and its level of the phosphorylation increased. Higher activity of superoxide dismutase ( SOD ) and ascorbate peroxidase ( APX ), Fｖ/Fm ( the maximal photochemical efficiency of PSII),ΦPSⅡ (the actual photochemical efficiency of PSⅡ）,qP (the photochemical quenching coefficient)and Fm/Fo (rate of electron transport through PSII) in SA-pretreated leaves were maintained under stress conditions. [ Conclusion] SA pretreatment improved PSII performance under high temperature and irradiance stress and pre vented D1 protein from damage.