棉花花铃期低温对叶片PSI和PSII光抑制的影响  

Effects of Low Temperature on PSI and PSII Photoinhibition in Cotton Leaf at Boll Stage

作　　者：肖飞 杨延龙[2] 王娅婷 马慧 张旺锋[2] XIAO Fei;YANG Yan-Long;WANG Ya-Ting;MA Hui;ZHANG Wang-Feng(College of Life Science, Shihezi University, Shihezi 832003, China;College of Agriculture, Shihezi University / Key Laboratory of Oasis Ecology Agriculture of Xinjiang Production and Construction Corps, Shihezi 832003, China)

机构地区：[1]石河子大学生命科学学院,新疆石河子832003 [2]石河子大学农学院/新疆生产建设兵团绿洲生态农业重点实验室,新疆石河子832003

出　　处：《作物学报》2017年第9期1401-1409,共9页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(U1203283)资助~~

摘　　要：选用陆地棉(Gossypium hirsutum L.)品种新陆早45号,在室外盆栽至开花结铃期后,移至人工气候室,模拟新疆棉花花铃期易出现的低温逆境条件,设置处理T(16℃/10℃,昼/夜),以常温(30℃/18℃,昼/夜)处理作为对照,采用叶绿素荧光和P700同步测定技术,研究低温对棉花花铃期叶片光合机构PSII能量分配、PSI氧化还原状态及环式电子传递流的影响。结果表明,与对照相比,低温处理显著降低了棉花叶片PSII光适应状态下最大光化学量子产量(F_v'/F_m')、光化学猝灭系数(qP)和PSII有效光化学量子产量[Y(II)],并使PSII非调节性能量耗散[Y(NO)]和调节性能量耗散[Y(NPQ)]量子产量显著升高,诱导PSII发生光抑制。低温引起棉花叶片光合机构PSI受体侧限制[Y(NA)]显著下降和供体侧限制[Y(ND)]显著升高,但未引起有效的PSI复合体含量(P_m)显著降低,表明与PSII相比,棉花叶片PSI对低温不敏感。此外,低温引起环式电子传递量子产量[Y(CEF)]以及与PSII实际量子产量比率的[Y(CEF)/Y(II)]显著升高,进一步表明在低温下,光破坏防御机制中环式电子传递流对棉花PSI、PSII起着重要的保护作用,是主要的光破坏防御机制。非光化学热耗散(NPQ)和调节性非光化学热耗散[Y(NPQ)]与[Y(CEF)]具有显著的正相关关系,表明低温引起棉花花铃期叶片PSII反应中心过度关闭产生过剩的激发能,造成了PSII可逆的光抑制,环式电子传递流的响应及较高的调节性能量耗散共同保护了棉花叶片PSI和PSII免受光抑制的损伤,这可能是棉花叶片PSI对低温不敏感的重要原因。Cotton(Gossypium hirsutum L.)variety Xinluzao45was grown in pots under low temperature until bolling stage and the seedings were moved in phytotron in northern Xinjiang.Chl fluorescence and P700+absorbance signal were determined simultaneously by Dual-PAM-100.The treatment was day/night temperature of16°C/10°C with a suitable temperature condition(30°C/18°C)as control.The light-adapted maximum quantum yield of PSII(Fv?/Fm?),photochemical quenching coefficient(qP)and effective quantum yield of PSII[Y(II)]decreased significantly under low temperature stress.Low temperature significantly increased non-photochemical quantum yield of PSI caused by donor side limitation[Y(ND)].The yield of regulated energy dissipation[Y(NPQ)]and non-regulated energy dissipation of PSII[Y(NO)]were significantly increased,including reversible photoinhibition in cotton leaf.Compared with control,low temperature stress significantly decreased the acceptor side limitation of PSI[Y(NA)]and increased donor side limitation of PSI[Y(ND)],while effective PSI complex content(Pm)was not significantly decreased,suggesting that PSI in cotton leaf is insensitive to low temperature compared with PSII.The quantum yield of cyclic electron flow[Y(CEF)]and the ratio of[Y(CEF)]to the effective quantum yield of PSII[Y(CEF)/Y(II)]were enhanced by low temperature stress in cotton suggesting that stimulation of cyclic electron flow plays an important role in protecting PSI and PSII from photoinhibition caused by low temperature stress in cotton.Furthermore,the non-photochemical quenching(NPQ)and regulated heat dissipation[Y(NPQ)]had significantly positive correlation with the quantum yield of cyclic electron flow[Y(CEF)],indicating that the strong excess excitation energy due to the overclosure of PSII reaction center results in reversible photoinhibition of PSII under low temperature stress.In conclusion,the strong stimulation of cyclic electron flow and regulated heat dissipation powerfully prevent PSII and PSI of cotton from photoinhibition and photodam

关 键 词：棉花 低温 光抑制 光合作用 环式电子传递流 

分 类 号：S562[农业科学—作物学]