干旱胁迫下外源褪黑素对小麦生长和光系统活性的影响  

Effect of Exogenous Melatonin on the Growth and Photosystem Activity of Wheat under Drought Stress

作　　者：李春雨 陈春宇 毛浩田 张怀渝[1] 陈洋尔[1] LI Chunyu;CHEN Chunyu;MAO Haotian;ZHANG Huaiyu;CHEN Yang'er(College of Life Science,Sichuan Agricultural University,Yaan,Sichuan 625014,China)

机构地区：[1]四川农业大学生命科学学院,四川雅安625014

出　　处：《麦类作物学报》2022年第7期846-856,共11页Journal of Triticeae Crops

基　　金：四川农业大学创新训练计划项目(201810626097)。

摘　　要：为了从光系统活性探讨褪黑素对干旱胁迫下小麦生长的调节作用,通过石英砂盆栽试验,设置对照(CK)、5μmol·L^(-1)褪黑素处理、25μmol·L^(-1)褪黑素处理、100μmol·L^(-1)褪黑素处理、干旱胁迫处理、5μmol·L^(-1)褪黑素+干旱胁迫处理、25μmol·L^(-1)褪黑素+干旱胁迫处理及100μmol·L^(-1)褪黑素+干旱胁迫处理,分析了根施褪黑素对干旱胁迫下小麦叶片生理和光合作用的影响。结果表明,干旱胁迫显著降低了小麦叶片的相对含水量、地上部生物量及光合效率,抑制了植株的生长,而干旱胁迫下25μmol·L^(-1)褪黑素处理最为显著地增加了小麦叶片相对含水量、地上部生物量及叶绿素含量,并显著提高了小麦叶片的净光合速率、气孔导度、光系统Ⅱ(PSⅡ)的最大荧光、PSⅡ最大光化学效率、远红光适应下的最大P_(700)改变量、光系统I(PSⅠ)的实际光能转换效率及PSⅠ供体侧限制引起的非光化学能量耗散的量子产量。相反,CO_(2)浓度和PSⅠ受体侧限制引起的非光化学能量耗散的量子产量下降。蛋白免疫杂交分析表明,外源褪黑素处理可显著减少干旱胁迫下Lhca2蛋白含量的下降。由此表明,干旱胁迫下褪黑素可通过改变叶片的水分状况和提高叶片的光合能力来减轻干旱胁迫对小麦植株生长的抑制作用。To investigate the effects of exogenous melatonin on the growth and photosynthesis of wheat under drought stress,through the pot experiment,the effects of melatonin on physiology and photosynthesis of wheat leaves were analyzed under the following treatments:control(CK)and 5μmol·L^(-1) melatonin treatment,25μmol·L^(-1) melatonin treatment,100μmol·L^(-1) melatonin treatment,drought stress treatment,5μmol·L^(-1) melatonin+drought stress treatment,25μmol·L^(-1) melatonin+drought stress treatment and 100μmol·L^(-1)melatonin+drought stress treatment.The results showed that drought stress significantly decreased the relative water content of wheat leaves,the aboveground biomass,and photosynthetic efficiency,and inhibited the growth of plants.However,25μmol·L^(-1) melatonin application significantly increased the relative water content,aboveground biomass and chlorophyll content of wheat leaves,the net photosynthetic rate,stomatal conductance,maximum fluorescence of photosystem Ⅱ(PSⅡ),maximum photochemical efficiency of PSⅡ,maximum P_(700)signal,quantum yield of PSⅠ,and oxidation status of PSⅠ donor side.In contrast,intercellular CO_(2)concentration and reduction status of PSⅠ acceptor side decreased under drought stress.In addition,the application of exogenous melatonin significantly alleviate the decreasing in the content of Lhca2 protein in wheat under drought stress.These findings indicated that melatonin could alleviate the damage to wheat through changing leaf water content and photosynthesis.We found that 25μmol·L^(-1) of melatonin presented the best roles in improving the resistance to drought in wheat.

关 键 词：小麦 干旱胁迫 褪黑素 生长 光合能力 

分 类 号：S512.1[农业科学—作物学] S311