《植物生理学报》 2015, 51(10): 1678-1686

土壤干旱和强光对高山嵩草叶片PSII反应中心非光化学猝灭的交互影响分析

师生波^1,2,*, 李天才¹, 李妙¹, 刘世增², 李爱德², 马剑平²

¹中国科学院西北高原生物研究所, 高原生物适应与进化重点实验室, 西宁810001; ²甘肃省治沙研究所, 甘肃民勤荒漠草地生态系统国家野外研究站, 兰州730070

通信作者：师生波；E-mail: sbshi@nwipb.cas.cn；Tel: 0931-7606125

摘　要：

本文采用叶绿素荧光图像分析手段, 研究了土壤干旱对高山嵩草(Kobresia pygmaea)叶片PSII非光化学猝灭中光诱导和非光诱导的量子产量的影响, 及其与稳态作用光强的交互效应。结果表明: 土壤干旱胁迫可加剧高山嵩草叶片光合作用的光抑制程度, 引起PSII最大光化学量子效率(F_v/F_m)的显著降低; 高光强下叶片PSII实际光化学量子效率(Φ_PSII)显著较低, 非光化学猝灭中光诱导的PSII调节性能量耗散量子产量(Φ_NPQ)则显著增大, 且为干旱胁迫所加剧; 干旱和强光胁迫对非调节性能量耗散量子产量(Φ_NO)的影响程度相对较小; 非光化学猝灭(NPQ)中快弛豫相组分(NPQ_f)约占2/3, 干旱胁迫可引起NPQ以及NPQ_f和慢弛豫相组分(NPQ_s)的升高。由此可知, ΦNPQ是高山嵩草响应强光和土壤干旱胁迫的敏捷途径, 高光强下的上调是光胁迫驯化的结果, 也是导致PSII反应中心Φ_PSII降低的主要原因; NPQ和Φ_NPQ存在着2种胁迫因子的交互效应, 而ΦPSII则无。

关键词：叶绿素荧光; 交互效应; 光抑制; PSII非光化学猝灭; 土壤干旱胁迫; 高山嵩草

收稿：2015-07-30   修定：2015-10-04

资助：青海省自然科学基金(2013–Z-915)和国家自然科学基金(30670307)。

Interaction Effect Analysis of Soil Drought and Strong Light on PSII Nonphotochemical Quenching in Kobresia pygmaea Leaves

SHI Sheng-Bo^1,2*, LI Tian-Cai¹, LI Miao¹, LIU Shi-Zeng², LI Ai-De², MA Jian-Ping²

¹Key Laboratory of Adaptation and Evolution of Plateau Biology, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China; ²Gansu Minqin National Studies for Desert Steppe Ecosystem, Gansu Desert Control Research Institute, Lanzhou 730070, China

Corresponding author: SHI Sheng-Bo; E-mail: sbshi@nwipb.cas.cn; Tel: 0931-7606125

Abstract:

Based on the analysis of chlorophyll fluorescence imaging in Kobresia pygmaea leaves, the quantum yield of quenching due to light-induced processes (Φ_NPQ) and non-light-induced processes (Φ_NO) in PSII non-photochemical energy dissipation (NPQ), and its fast and slow relax component of NPQ (NPQ_f and NPQ_s) were explored, and the interaction effect of soil drought and strong light was analyzed. The results indicate that soil drought stress could cause severe photosynthetic photoinhibition, and cause a significant induction in the maximum quantum efficiency of PSII photochemistry (F_v/F_m). With the increase of actinic light intensity, PSII actual photochemical efficiency (Φ_PSII) decreased and Φ_NPQ increased, these tendencies could be imposed by soil drought stress, and Φ_NO exhibited only small variation. NPQ_f was the main compound with ratio of 2/3 in NPQ, and both NPQ_f and NPQ_s were enhanced after soil drought stress. The results demonstrate that Φ_NPQ could quickly response to drought and strong light stress in alpine plant K. pygmaea, and was the main reason of variation of Φ_PSII to both stress factors; PSII non-photochemical quenching and light-induced compounds were exacted interaction effects between soil drought and light intensity, and depress of Φ_PSII with increasing of light intensity did not imposed by soil drought stress.

Key words: chlorophyll fluorescence; interaction effect; photoinhibition; PSII non-photochemical quenching; soil drought stress; Kobresia pygmaea