低温胁迫对不同耐寒红树植物幼苗光合生理和抗氧化特性的影响  

Effects of Low Temperature Stress on Leaf Photosynthetic Physiology and Antioxidant Characteristics in Mangrove Plants Seedlings with Different Cold Tolerance

作　　者：许明海 冯瑜 童宇艳 岳丹斐 张慧玉 郑春芳 XU Ming-hai;FENG Yu;TONG Yu-yan;YUE Dan-fei;ZHANG Hui-yu;ZHENG Chun-fang(Bureau of Natural Resources and Planning of Pingyang,Wenzhou 325400,Zhejiang,China;National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution,College of Life and Environmental Science,Wenzhou University,Wenzhou 325035,Zhejiang,China;Fenggang Middle School,Ningbo315500,Zhejiang;Wuyi County Experimental Primary School,Wuyi 524048,Zhejiang,China)

机构地区：[1]平阳县自然资源和规划局,浙江温州325400 [2]城镇水污染生态治理技术国家地方联合工程研究中心温州大学生命与环境科学学院,浙江温州325035 [3]奉港中学,浙江宁波315500 [4]武义县实验小学,浙江武义321200

出　　处：《林业科学研究》2024年第2期124-133,共10页Forest Research

基　　金：国家自然科学基金(32071503);温州市基础科研项目(S20220011)。

摘　　要：[目的]探索两种不同耐寒红树植物对低温胁迫的生理响应机制,为红树林抗寒性研究提供重要理论依据。[方法]以秋茄、红榄李幼苗为试验材料,设置25℃(昼)/20℃(夜)、24 h7℃(昼)/4℃(夜)、48 h7℃(昼)/4℃(夜)3个处理,分别比较分析了两种红树植物幼苗叶片的光合参数、荧光特征、抗氧化能力、叶绿体超微结构等生理过程对低温响应的差异。[结果]低温胁迫抑制红榄李幼苗生长和光合作用,而对秋茄的影响却较小。在低温胁迫处理48 h后,红榄李幼苗叶片超氧歧化酶(SOD)、过氧化物酶(POD)活性显著降低,而超氧阴离子(O_(2)^(·-))、过氧化氢(H_(2)O_(2))含量、丙二醛(MDA)含量增加,同时气孔关闭,光合色素合成受阻,叶绿体超微结构受损,最终导致叶片净光合速率(P_(n))、气孔导度(G_(s))、最大光化学效率(F_(v)/F_(m))、实际光化学效率(φ_(PSⅡ))、光化学猝灭系数(qP)以及非光化学猝灭系数(NPQ)等降低。相同低温胁迫下秋茄幼苗叶片P_(n)也受到抑制,但其P_(n)下降幅度约为红榄李的79%。[结论]秋茄耐寒能力较强于红榄李,这可能是因为秋茄在低温胁迫下不仅能够保持较高的气孔开张度、光合色素含量以及POD活性,维持较好的叶绿体超微结构,而且还会通过调控能量耗散减轻PSⅡ光抑制,降低低温胁迫带来的膜脂过氧化伤害,最终维持自身较强的光合能力。[Objective]This study investigates the physiological response of two different cold-tolerant mangrove plant species to low temperature stress,which provides a theoretical basis for studying on cold resistance of mangrove.[Method]Based on the cold-tolerant variety Kandelia obovata and the non-cold-tolerant variety Lumnitzera littore,three temperature treatments were set for treatment,including 25℃/20℃(day/night),24 hours at 7℃/4℃(day/night),and 48 hours at 7℃/4℃(day/night).The differences in the of photosynthetic parameters and fluorescence characteristic,antioxidant capacity,chloroplast ultrastructure of two mangrove seedlings were compared and analyzed.[Result]Low-temperature stress inhibited the growth and photosynthesis of L.littore seedlings but had less effect on K.obovate.After 48 hours of low-temperature stress treatment,the activities of superoxide dismutase(SOD)and peroxidase(POD)in the leaves of L.littore seedlings were reduced,but the content of superoxide anion(O_(2)^(·-)),malondialdehyde(MDA)and hydrogen peroxide(H_(2)O_(2))in L.littore seedlings were increased.It was also observed that the leaf stomata were closed,and the contents of photosynthetic pigments were decreased.Additionally,the ultrastructure of the chloroplast was damaged,which eventually led to a decrease in the net photosynthetic rate(P_(n)),stomatal conductance(G_(s)),maximum photochemical efficiency(F_(v)/F_(m)),actual photochemical efficiency(Φ_(PSⅡ)),photochemical quenching coefficient(qP),and non-photochemical quenching coefficient(NPQ)of the leaves.Under the same low-temperature stress,the photosynthesis of K.obovata seedlings’leaves was also inhibited,but the decrease in leaf P_(n) was approximately 79% of that observed in L.littore.[Conclusion]K.obovata exhibits stronger cold tolerance than L.littore,possibly because K.obovata can not only maintain higher stomatal opening,photosynthetic pigment content,and POD activity,reducing the damage to chloroplast ultrastructure,but also regulate energy dissipation to al

关 键 词：红树林 低温 光合荧光 抗氧化系统 叶绿体结构 

分 类 号：S718.43[农业科学—林学]