褪黑素对玉米幼苗根系发育和抗旱性的影响  

Effects of Melatonin on Root Growth and Drought Tolerance of Maize Seedlings

作　　者：马旭辉 陈茹梅[1] 柳小庆[1] 赵军[1] 张霞[1] MA Xu-hui;CHEN Ru-mei;LIU Xiao-qing;ZHAO Jun;ZHANG Xia(Biotechnology Research Institute,Chinese Academy of Agricultural Sciences,Beijing 100081)

机构地区：[1]中国农业科学院生物技术研究所,北京100081

出　　处：《生物技术通报》2021年第2期1-14,共14页Biotechnology Bulletin

基　　金：国家重点研发计划(2016YFD0101002)。

摘　　要：褪黑素是一种在生物体内广泛存在的吲哚胺类化合物,参与植物的多种生理和生化过程。近年来研究认为褪黑素可以不同程度地增强植物的抗逆性,但对其作用机理仍知之甚少。通过两种褪黑素的施用方法,详细研究了褪黑素对于玉米根系发育和抗旱性的影响。首先,采用水培根灌褪黑素的方法对玉米幼苗的根系和生长状况进行分析,结果表明施加褪黑素显著提高多种玉米幼苗根系参数,包括根长、根表面积、根体积和侧根数目等。其次,采用盆栽浸种褪黑素的方法,对叶片相对含水量、光合作用、抗氧化酶活性、地上部分生物量等进行测定,结果表明在干旱胁迫条件下,褪黑素浸泡种子的处理方式能够提高植株的光合速率、气孔导度和蒸腾速率,增强抗氧化酶活性以及降低活性氧和丙二醛含量,证明褪黑素促进植物根系发育,减轻氧化损伤,缓解光合抑制,改善植物水分状况,从而提高植物抗旱性。Melatonin(N-acetyl-5-methoxy-tryptamine),an indoleamine neurohormone widely existing in organism,involves in many physiological and biochemical processes of plants.Recent studies understand that melatonin application may improve plant stress tolerance at varied level;however,the specific underlying mechanisms are still not fully understood.The current study was carried out to investigate the effect of melatonin on maize root system and drought tolerance via 2 applications of melatonin.Firs,the method of hydroponic root maize and irrigating melatonin were used to analyze the root system and growth status of maize seedlings.The results showed that the application of melatonin significantly improved a variety of maize seedling root parameters,including root length,root surface area,root volume,number of lateral roots,etc.Secondly,the method of melatonin-soaked seeds in pot was used to determine the relative water content of leaves,photosynthesis,antioxidant enzyme activity,and above-ground biomass.The results showed that under drought stress,the method of melatonin-soaked seed improved plant photosynthesis rate,stomatal conductance and transpiration rate,enhanced antioxidant enzyme activity,and reduced reactive oxygen species and malondialdehyde content.Our current findings hereby confirmed the beneficial effects of melatonin application in enhancing maize drought tolerance by promoting root growth,reducing oxidative damages,eliminating photosynthetic inhibition,and improving plant water status.

关 键 词：褪黑素 根系构型 抗氧化 光合作用 抗旱性 

分 类 号：S513[农业科学—作物学]