中国农业科学2024，Vol.57Issue(21)：4205-4220,16.DOI:10.3864/j.issn.0578-1752.2024.21.004
高温干旱复合胁迫抑制夏玉米光系统Ⅱ性能降低籽粒产量
High Temperature and Drought Combined Stress Inhibited Photosystem Ⅱ Performance and Decreased Grain Yield of Summer Maize
摘要
Abstract
[Objective]This study aimed to explore the underlying reasons for the reduction of maize photosynthesis under the high temperature and drought combined stress,so as to provide theoretical basis for alleviating the combined stress of high temperature and drought.[Method]Maize cultivar"Denghai 605"was selected as the experimental material for this experiment.Two temperature levels were set,namely normal temperature control(30℃/22℃for day(8:00-18:00)/night(18:00-8:00 the next day))and high temperature treatment(38℃/28℃for day/night).The two water conditions were normal water supply control(soil water content was 70％-80％of field capacity)and drought treatment(soil water content was set to 50％-60％of field capacity).There were four treatments in the experiment,including control(CK),high temperature stress(H),drought stress(D),high temperature and drought combined stress(HD),and the treatment began at VT stage(VT).The changes in leaf gas exchange parameters,photosystemⅡ(PSⅡ)performance,key photosynthetic enzyme activity,plant biomass,and grain yield under different stress treatments were analyzed.[Result]High temperature,drought and combined stress all led to the increase of chlorophyll fluorescence parameters,the ratio of a variable fluorescence FK to F0-FJ amplitude(WK)and variable fluorescence FJ to F0-FJ amplitude(VJ),and damaged the donor side and acceptor side of PSⅡ.Compared with the control,PSⅡ maximum quantum yield for primary photochemistry(φP0),the probability of captured excitons transferring electrons to other electron acceptors in the electron transfer chain beyond QA(Ψ0),quantum yield for electron transport(φE0),quantum yield of energy dissipation(φD0),quantum yield for reduction of the end electron acceptors at the PSI acceptor side(φR0),and performance index based on absorption of light energy(PIABS)were significantly decreased,and the absorption and transfer of light energy were inhibited;absorbed photon flux per active PSⅡ(ABS/RC),trapped energy flux per active PSⅡ(TR0/RC)and dissipated energy flux per active PSⅡ(DI0/RC)increased significantly,but the electron flux from QA‒ to the PQ pool per active PSⅡ(ET0/RC)decreased significantly,which affected the energy distribution of reaction centers,reduced the number of PSⅡ active reaction centers,and inhibited the performance of PSⅡ.Combined stress could aggravate the inhibition of PSⅡ performance by damaging the donor side,the acceptor side and the active reaction center.At the same time,the activities of ribose 1,5-diphosphate carboxylase(Rubisco)and phosphoenolpyruvate carboxylase(PEPCase)decreased,which inhibited photosynthetic carbon assimilation.High temperature,drought,and combined stress reduced the net photosynthetic rate by reducing the performance of PSⅡ and the activity of key photosynthetic enzymes.Compared with the control,the net photosynthetic rate of VT+5 d was reduced by 14.6％,31.4％,and 39.9％,respectively.The decrease in photosynthetic rate inhibited the accumulation of biomass and its transport to grains.Under high temperature,drought,and combined stress,the grain yield decreased by 80.3％,27.1％,and 84.0％than that under control,respectively.[Conclusion]In summary,the combined stress of high temperature and drought mainly reduced net photosynthetic rate,hindered biomass,and reduced grain yield by inhibiting leaf PSⅡ performance.The impact of combined stress on PSⅡ performance and grain yield was greater than that of single stress under high temperature and drought.关键词
高温干旱复合胁迫/净光合速率/光系统Ⅱ/光合酶/籽粒产量/夏玉米Key words
high temperature and drought combined stress/net photosynthetic rate/PSⅡ/photosynthetic enzyme/grain yield/summer maize引用本文复制引用
郭娅,任昊,王洪章,张吉旺,赵斌,任佰朝,刘鹏..高温干旱复合胁迫抑制夏玉米光系统Ⅱ性能降低籽粒产量[J].中国农业科学,2024,57(21):4205-4220,16.基金项目
国家自然科学基金(32071959)、山东省玉米产业技术体系(SDAIT02-08) （32071959）
