低温对高山嵩草叶片光化学和非光化学能量耗散特征的影响  

Effects of low temperature on photochemical and non-photochemical energy dissipation of Kobresia pygmaea leaves

作　　者：师生波[1,4] 师瑞 周党卫[1,3] 张雯 SHI Sheng-Bo;SHI Rui;ZHOU Dang-Wei;ZHANG Wen(Key Laboratory of Adaptation and Evolution of Plateau Biology,Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810001,China;Guangdong Berke Biomedical Co.,Ltd.,Shaoguan Institute of Biomedicine,Shaoguan,Guangdong 512500,China;College of Pharmacy,Qinghai Nationalities University,Xining 810007,China;Key Laboratory Breeding Base of Desertification and Aeolian Sand Disaster Combating,Gansu Desert Control Research Institute,Lanzhou 730070,China)

机构地区：[1]中国科学院西北高原生物研究所,中国科学院高原生物适应与进化重点实验室,西宁810001 [2]韶关生物经济高等研究院,广东伯克生物医药有限公司,广东韶关512500 [3]青海民族大学药学院,西宁810007 [4]甘肃省治沙研究所,甘肃省荒漠化与风沙灾害重点实验室培育基地,兰州730070

出　　处：《植物生态学报》2023年第10期1441-1452,共12页Chinese Journal of Plant Ecology

基　　金：青海省自然科学基金(2019-ZJ-7016);青海省创新平台建设专项(2017-ZJ-Y20和2021-ZJ-Y05)。

摘　　要：低温是青藏高原地区植物生长季内频繁发生的非生物胁迫,然而其对典型高山植物叶片光能利用和分配的影响如何,尚缺乏研究。该研究以高寒草甸优势种高山嵩草(Kobresia pygmaea)为材料,采用叶绿素荧光成像分析技术,研究了低温对光系统Ⅱ(PSⅡ)光化学及非光化学猝灭中光诱导和非光诱导的量子产量相对份额的影响。结果表明:PSⅡ最大光化学量子效率(F_(v)/F_(m)和1/F_(o)-1/F_(m))的最适温度在10℃左右,且变异系数(CV)较小;PSⅡ相对电子传递速率(rETR)的光响应曲线随温度降低而整体下移,其初始斜率(α)也相应降低。低温逆境可引起PSⅡ实际光化学量子效率(Φ_(PSⅡ))和非光化学猝灭中非调节性能量耗散量子产量(Φ_(NO))的降低,及调节性能量耗散量子产量(Φ_(NPQ))的增大,并导致均值CV的增高。1000μmol·m^(-2)·s^(-1)稳态光强下,Φ_(PSⅡ)、Φ_(NPQ)和Φ_(NO)三组分的相对比率在20、10、5、0和-5℃分别为:23:57:20、18:63:19、15:68:17、11:75:14和8:80:12。PSⅡ反应中心光化学效率的相对限制(LPPFD)随温度降低而逐渐增大,且光强越大其限制增强。一般线性模型的双因素方差分析表明,PSⅡ光化学和非光化学能量耗散过程没有交互效应产生。尽管光化学能量转换和保护性的调节机制可有效分配激发能,能避免Φ_(NO)的增加,但高山嵩草叶片的光合机构在维持运行的同时依然承受着来自低温的胁迫,是影响植物光合生理过程及限制生长发育的重要因素。Aims Kobresia pygmaea is a typical low temperature-tolerant arid mesophyte,and mainly distributes at low slope and high mountains ranging from 3000 to 5960 m on the Qingzang Plateau.Low temperature is a frequently occurring abiotic stress factor during the plants growing season on the Qingzang Plateau.The objectives of this study were to analyze the photochemical and non-photochemical energy distribution characteristics of the photosystem Ⅱ(PSⅡ)reaction center of K.pygmaea leaves,and explore their quenching protection mechanism in response to low temperature stress.Methods Turf blocks(30 cm×30 cm)of K.pygmaea meadow were collected from the Alpine Grassland Ecosystem Research Station of the Resource of Three Rivers,moved and kept in a culture room with air temperature of 24℃/18℃(day/night)at a diurnal photoperiod of 12 h and relative humidity of 45%;being irradiated with artificial LED light source of 500μmol·m^(-2)·s^(-1) light intensity.When the turf black had been kept in culture room for one day,the measurements of chlorophyll fluorescence were performed immediately using chlorophyll fluorescence imager with built-in protocol.The trial of light response curves at different leaf temperatures,temperature response at a steady-state light intensity and light-temperature interaction effects were performed at controlled temperature using thermostatic control instruments.Based on the“Lake Model”,the relative variation of the PSⅡ actual photochemical efficiency(Φ_(PSⅡ)),the quantum yield of regulated energy dissipation(Φ_(NPQ))and non-regulated energy dissipation(Φ_(NO))were investigated.Furthermore,the interaction effects of low temperature and high light intensity was analyzed by two-way ANOVA of the general linear model(GLM).Important findings The maximum quantum efficiency of PSⅡ photochemistry(F_(v)/F_(m) and 1/F_(o)-1/F_(m))were higher at 10℃ and their coefficient of variation(CV)was smaller relative to other temperatures.The rapid light-response curves of the PSⅡ relative electron t

关 键 词：低温逆境 光系统Ⅱ非光化学猝灭 高山嵩草 青藏高原 叶绿素荧光 

分 类 号：Q945[生物学—植物学]