《植物生理学报》 2015, 51(11): 1947-1954

不同浓度臭氧处理对‘赤霞珠’葡萄叶片光系统II功能的影响

孙永江, 王金欢, 耿庆伟, 邢浩, 翟衡, 杜远鹏^∗

山东农业大学园艺科学与工程学院/作物生物学国家重点实验室, 山东泰安271018

通信作者：杜远鹏；E-mail: duyuanpeng001@163.com；Tel: 0538-8241335

摘　要：

探讨O₃处理对‘赤霞珠’葡萄叶片光系统功能II (PSII)的伤害机制及O₃胁迫发生阈值。以一年生‘赤霞珠’为试材, 设置不同O₃浓度(25、40、55、80和105 nL•L^-1), 测定叶片叶绿素含量、气体交换和叶绿素荧光参数, 分析不同O₃浓度处理对葡萄叶片PSII活性的影响。结果表明, 随着O₃浓度升高, 叶片净光合速率(P_n)、气孔导度(G_s)、PSII的实际光化学效率(Φ_PSII)、光下最大光化学效率(F_v’/F_m’)、捕获光能用于Q_A以后的电子传递的概率(Ψ_Eo)、单位面积有活性反应中心的数量(RC/CS_m)均呈下降趋势; PSII激发压(1-qP)、K点的相对可变荧光(W_k)、慢相荧光淬灭(qI)呈现上升趋势; 在低O₃浓度条件下(25~55nL•L^-1), P_n的下降主要是由于气孔限制引起的, O₃浓度达到并超过80 nL•L^-1时, 叶绿素含量显著降低, 非气孔限制占主导因素, PSII功能开始受到抑制; 浓度达到105 nL•L^-1时叶片出现较明显的表观伤害症状, 电子供体侧伤害程度大于受体侧。实验结果说明, 葡萄叶片可以在短时间内(8 h)忍受一定浓度(不超过55 nL•L^-1)的O₃胁迫, O₃浓度达到或超过80 nL•L^-1时, PSII功能受到较严重的抑制。

关键词：葡萄; O₃; 气体交换和叶绿素荧光参数; 光系统II

收稿：2015-07-21   修定：2015-10-03

资助：国家葡萄产业技术体系(CARS-30)、国家自然科学基金(31572084)和长江学者和创新团队发展计划项目(IRT1155)。

Effects of Different Concentrations of Ozone Stress on Photosynthetic System II in Vitis vinifera cv. ‘Cabernet Sauvignon’

SUN Yong-Jiang, WANG Jin-Huan, GENG Qing-Wei, XING Hao, ZHAI Heng, DU Yuan-Peng^*

College of Horticultural Science and Engineering, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai’an, Shandong 271018, China

Corresponding author: DU Yuan-Peng; E-mail: duyuanpeng001@163.com; Tel: 0538-8241335

Abstract:

The effects of O₃ treatments on the operation of photosynthetic apparatus were investigated to reveal the mechanism of inhibition of photosynthetic system II (PSII). One-year-old ‘Cabernet Sauvignon’ grapevines were treated with different O₃ concentrations (25, 40, 55, 80 and 105 nL•L^-1). Chlorophyll concentration, gas exchange and chlorophyll a fluorescence parameters were simultaneously analyzed to investigate the effects of different O₃ concentrations on the PSII function. The results showed net photosynthetic rate (P_n), stomatal conductance (G_s), actual PSII efficiency (Φ_PSII), electron transport rate (ETR), density of RCs (RC/CS_m) and the probability that a trapped exciton moves an electron into the electron transport chain beyond QA (Ψ_Eo) continually decreased with the increase of PSII excitation pressure (1-qP), slowly-relaxing quenching (qI) and relative variable fluorescence intensity at K-step (W_k). Under the low O₃ concentrations (25–55 nL•L^-1), the decrease of P_n was due mainly to stomatal limitation. When the O₃ concentration reached 80 nL•L^-1, chlorophyll concentration decreased significantly, the non-stomatal limitation played dominant role in decline of photosynthesis and PSII function began being inhibited, the treated leaves even showed obvious injury symptoms and the damage degree of the donor side was more sever than that of the acceptor side under treatment of 105 nL•L^-1. The experiments showed that grape leaves could cope with certain O₃ concentration (less than 55 nL•L^-1) within 8 h, however, over the concentration of 80 nL•L^-1 resulted in serious photoinhibition of PSII.

Key words: Vitis vinifera; O₃; gas exchange and chlorophyll a fluorescence parameters; PSII