摘要
为探究干旱胁迫及复水后外源褪黑素对玉米叶片光合作用的影响和调控机制。以玉米陕单609盆栽苗为试验材料,叶面喷施褪黑素100μmol/L在重度干旱和复水后分别测定了生物量、净光合速率(Pn)以及光合电子传递速率等指标。结果显示:外源褪黑激素可减轻干旱胁迫引起的生长抑制;外源褪黑激素处理的植株表现出比未处理植株更高的Pn、气孔导度(Gs)以及更低的胞间CO2浓度(Ci);外源褪黑素增加了干旱胁迫下OJIP曲线的荧光参数φP0、φE0、ψ0以及光合性能指数PIabs;外源褪黑素也提高了干旱胁迫下叶片PSII和PSI有效量子产量[Y(II),Y(I)];也增加了干旱胁迫下叶片的PSII和PSI电子传递速率(ETRII,ETRI),但降低了干旱胁迫下叶片PSI受体侧限制[Y(NA)]和供体侧限制[Y(ND)]。表明外源褪黑素对干旱胁迫下光抑制具有一定的缓解作用。复水后,干旱胁迫下褪黑素处理玉米叶片各参数都恢复到对照水平;而干旱胁迫处理玉米叶片各参数复水后不能完全恢复。可见,喷施褪黑素不仅缓解干旱胁迫对玉米PSII和PSI结构和功能的损伤,而且能加速复水后光合机构功能的恢复,促进玉米植株恢复性生长。因此喷施褪黑素加强玉米叶片光合作用适应干旱环境是一种重要的调控方式。
In order to explore the effects of exogenous melatonin on photosynthetic apparatus of maize leaves under drought stress and rewatering and clarify the physiological mechanisms involved,the biomass,net photosynthetic rate(Pn),and photosynthetic electron transfer rate in seedlings of maize shaandan609 with or without 100μmol/L melatonin application were analyzed after severe drought and rewatering..The results showed that exogenous melatonin alleviated growth inhibition caused by drought stress.Further investigation demonstrated that,under drought condition,melatonin-treated plants indicated higher Pn and stomatal conductance(Gs),as well as lower intercellular CO2 concentration(Ci)than those untreated plants.In addition,exogenous melatonin increased the fluorescence parametersφP0,φE0,ψ0 and photosynthetic performance index PIabs of OJIP curve under drought stress.It also improved the effective quantum yield of PSII and PSII under drought stress[Y(II),Y(I)].The melatonin treatment decreased the PSI receptor side limitation[Y(NA)]and donor side limitation[Y(ND)]of leaf photosynthetic apparatus after drought stress.Moreover,exogenous melatonin increased the electron transfer rate(ETRII,ETRI)of PSII and PSII in maize leaves under drought stress,indicating that exogenous melatonin could alleviate photo-inhibition under drought stress.After rewatering,all the parameters of maize leaves treated with melatonin returned to the control level under drought stress,while the parameters of maize leaves treated with drought stress could not recover after rehydration.It can be concluded that exogenous spraying melatonin can not only alleviate the damage of PSII and PSI structure and function of maize caused by drought stress,but also accelerate the recovery of photosynthetic apparatus function after rewatering,resulting in improving the recovery of maize seedling growth.Therefore,exogenous melatonin application could be an important regulation mode to adapt to arid environment by enhancing photosynthesis of maize leaves.
作者
赵成凤
王晨光
李红杰
郑学慧
杨梅
张仁和
ZHAO Chenfeng;WANG Chenguang;LI Hongjie;ZHENG Xuehui;YANG Mei;ZHANG Renhe(College of Agronomy,Northwest A&F University,Yangling 712100,China;Shaanxi Agronomy and Technology Extension Station,Xi'an 710000,China)
出处
《生态学报》
CAS
CSCD
北大核心
2021年第4期1431-1439,共9页
Acta Ecologica Sinica
基金
国家重点研发计划项目(2017YFD0300304)
陕西省技术创新引导专项(2019TG-002)
陕西省重点研发计划项目(2017ZDCXL-NY-02-02)。
关键词
玉米
干旱和复水
褪黑素
电子传递链
光能分配
maize
drought stress and rewatering
melatonin
photosynthetic electron transport chain
light energy distribution
