作物学报2017，Vol.43Issue(9)：1401-1409,9.DOI:10.3724/SP.J.1006.2017.01401
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
摘要
Abstract
Cotton (Gossypium hirsutum L.) variety Xinluzao 45 was 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 of 16°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 dissi-pation [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 signifi-cantly 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 photodamage induced by low temperature stress, which may be the main mechanism of the insusceptibility of PSI in cotton to low temperature stress.关键词
棉花/低温/光抑制/光合作用/环式电子传递流Key words
Cotton/Low temperature/Photoinhibition/Photosynthesis/Cyclic electron transport flow引用本文复制引用
肖飞,杨延龙,王娅婷,马慧,张旺锋..棉花花铃期低温对叶片PSⅠ和PSⅡ光抑制的影响[J].作物学报,2017,43(9):1401-1409,9.基金项目
本研究由国家自然科学基金项目(U1203283)资助. This study was supported by the National Natural Science Foundation of China (U1203283). （U1203283）
