依赖于叶黄素循环的热耗散对茶树叶片防御强光破坏的相关试验研究

经叶黄素循环抑制剂——二硫苏糖醇(DIT)处理的茶树叶片，以850μmol．m^-2．s^-1的PFD照射120min后，福鼎大白茶的叶黄素循环组分中的环氧玉米黄素(A)和玉米黄素(Z)含量之和降低了76．5％，结果导致非光化学猝灭(NPQ)、光系统Ⅱ(PSⅡ)的光化学效率(Fv／Fm)、光化学猝灭系数(qP)、PSⅡ实际光化学量子效率(ψPSⅡR)和光合电子传递速率(ETR)明显下降，而F0显著上升，暗恢复后Fv／Fm恢复程度小于未经DIT处理的叶片。自然光强下，NPQ与与叶黄素循环的脱环氧化程度(A Z)/(V A Z)比值呈明显的正线性关系(R=0．9488^***)。这些结果充分证明依赖与叶黄素循环的热耗散是茶树叶片光合器官防御强光破坏的主要途径。

Study of Experiments on Thermal Dissipation Depending on Xanthophyll Cycle Preventing Light Energy from Damaging to Leaves of Tea Plant ( Camellia sinensis )

The content of antheraxanthin(A) and zeaxanthin(Z) in the leaves of Fuding, treated with dithiothretol(DTT), decreased by 76.5 % after exposed to the photon flux density PFD of 850μmol.m~(-2).s~(-1), that resulted in remarkable decreases of non-photochemical quenching(NPQ), photochemical efficiency of PSⅡ(F_v/F_m ), photochemical quenching(qP), quantum efficiency of PSⅡ(φPSⅡR) and electron transport rate (ETR); on the contrary, increase of fluorescence origin(F_o), furthermore, decrease of the level of recovery of F_v/F_m. In addition, A positive linear correlation between NPQ and the extent of de-epoxidation of xanthophyll cycle[(A+Z)/(V+A+Z)] was significant(R=0.9488~(***)). Our results demonstrated that the thermal dissipation depending on xanthophyll cycle plays an important role in preventing light energy from damaging to tea plant.