两种红树植物不同种源幼苗对模拟高温热浪的光合生理响应差异  

Differences in photosynthetic responses to simulated heat wave in seedlings of two mangrove species from different provenances

作　　者：张小燕 Alison Kim Shan Wee Tadashi Kajita 朱俊杰[1] 曹坤芳 Zhang Xiao-Yan;Alison Kim Shan Wee;Tadashi Kajita;Zhu Jun-Jie;Cao Kun-Fang(State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Forest Ecology and Conservation,College of Forestry,Guangxi University,Nanning 530004,China;Iriomote Station,Tropical Biosphere Research Center,University of the Ryukyus,Okinawa,Japan 9071541)

机构地区：[1]广西大学亚热带农业生物资源保护与利用国家重点实验室,南宁530004 [2]广西大学林学院,广西森林生态与保育重点实验室,南宁530004 [3]琉球大学热带生物研究中心,西表研究站,日本冲绳县9071541

出　　处：《植物科学学报》2021年第4期424-432,共9页Plant Science Journal

基　　金：国家自然科学基金(31670406);八桂学者人才项目(33600992001)。

摘　　要：以来自中国广西(较低纬度)和日本冲绳(较高纬度)两个地理种群的耐冷秋茄(Kandelia obovata Sheue,H.Y.Liu&J.Yong)和耐热木榄(Bruguiera gymnorrhiza(L.)Savigny)为材料,测定其光系统Ⅰ(PSⅠ)和光系统Ⅱ(PSⅡ)活性参数、叶黄素循环组分和叶绿素a、b的含量,并分析他们经高温处理后光合生理响应的差异。结果显示:高温处理使植物PSⅡ最大光化学潜能(F v/F m)显著降低,降低幅度为较低纬度种群<较高纬度种群、木榄幼苗<秋茄幼苗;P700氧化还原状态(P m)降低,降低幅度为较低纬度种群<较高纬度种群;叶片非光化学猝灭(NPQ)升高,表现为较低纬度种群>较高纬度种群、木榄幼苗>秋茄幼苗。高温处理引起叶黄素库容量(V+A+Z)和脱环氧化状态(A+Z)/(V+A+Z)升高,表现为较低纬度种群>较高纬度种群;(A+Z)/(V+A+Z)与F v/F m负相关,而与NPQ正相关。常温恢复第2 d,高纬度种源秋茄幼苗F v/F m仍为0.69,表明其PSⅡ受到不可逆的损伤,而其余种源幼苗的F v/F m均恢复到正常水平,且所有种源幼苗仍保持较高的NPQ以及叶黄素脱环氧化比率,起光保护作用。与萨瓦纳和地中海型生境相比,红树林有最大的叶黄素库。研究结果表明,低纬度种群对高温胁迫具有较高的适应性,部分原因是叶黄素循环具有较强的光保护作用,物种及种源间存在耐冷和耐热性的权衡。We analyzed the impact of two days of high-temperature treatment on the leaf photosystem properties of potted seedlings of two mangrove species,i.e.,cold-tolerant Kandelia obovata Sheue,H.Y.Liu&J.Yong and heat-tolerant Bruguiera gymnorrhiza(L.)Savigny,from two geographical populations in Guangxi,China(lower latitude)and Okinawa,Japan(higher latitude).The xanthophyll cycle components and chlorophyll-a and-b contents were measured.The leaf photosystemⅠ(PSⅠ)and photosystemⅡ(PSⅡ)activities were measured using a Dual-PAM-100 system.Results showed that high temperature significantly reduced the maximum photochemical efficiency(F v/F m)of PSⅡin both species.The F v/F m values showed less decrease in the lower latitude populations than in the higher latitude populations,and less decrease in B.gymnorrhiza than in K.obovata seedlings.The P700 oxidation-reduction state(P m)showed less decrease in the lower than higher latitude populations.The leaf non-photochemical quenching(NPQ)showed a greater increase in the lower latitude populations than in the higher latitude populations.The xanthophyll pool size(V+A+Z)and de-epoxidation ratio(A+Z)/(V+A+Z)increased following heat treatment.A greater increase was observed in the lower latitude populations than in the higher latitude populations.In addition,the(A+Z)/(V+A+Z)ratio was negatively correlated with F v/F m,but positively correlated with NPQ.Compared with other hardy habitats,such as savannas and Mediterranean woodlands,mangroves had the largest xanthophyll pool size.On the second day of recovery,F v/F m was still at 0.69 in the high-latitude K.obovata seedlings,indicating irreversible photoinhibition of PSⅡ,while all seedlings maintained a higher de-epoxidation ratio and NPQ for photosystem protection.In conclusion,the lower latitude populations showed higher adaptability to heat stress,which was partly due to strong photoprotection through the xanthophyll cycle,and there was a tradeoff between cold-and heat-tolerance between species and populations.This study rev

关 键 词：红树植物 光合系统 高温胁迫 叶黄素循环 种源差异 

分 类 号：Q945[生物学—植物学]