外源褪黑素预处理对干旱胁迫下桃苗生长的缓解效应  

The mitigative effect of exogenous melatonin pretreatment on peach seedling growth under drought stress

作　　者：古咸彬 陆玲鸿 宋根华[1] 肖金平[1] 张慧琴[1] GU Xianbin;LU Linghong;SONG Genhua;XIAO Jinping;ZHANG Huiqin(Institute of Horticulture,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China)

机构地区：[1]浙江省农业科学院园艺研究所,杭州310021

出　　处：《植物生理学报》2022年第2期309-318,共10页Plant Physiology Journal

基　　金：国家现代农业产业技术体系(CARS-30-Z-06);浙江省农业(果品)新品种选育重大科技专项(2021C02066-4)。

摘　　要：用不同浓度褪黑素对桃苗进行预培养然后进行干旱处理,探究褪黑素预处理诱导桃苗耐旱性的生理机制。结果表明褪黑素使气孔开度减小,干旱胁迫下褪黑素增强了桃苗的根系活力,提高了叶片相对含水量和相对叶绿素含量。褪黑素通过抑制H_(2)O_(2)和丙二醛(MDA)的生成,增强抗氧化酶的活性,从而缓解干旱对桃苗的氧化伤害。桃苗对干旱的应激反应使DREB1A、DREB2A、LEA和PIP1等逆境响应基因的表达量升高,褪黑素能进一步提高相关基因的表达水平,促进桃苗对干旱环境的适应。褪黑素处理具有剂量效应,中低浓度(100~200μmol·L^(-1))的作用效果更为明显。Peach seedlings were pre-cultured with different concentrations of melatonin and then subjected to drought treatment, which was used to explore the physiological mechanism of melatonin pretreatment increasing drought tolerance in peach. The results showed that melatonin pretreatment reduced the stomatal aperture. Under drought stress, melatonin enhanced the root activity, and increased the relative water content and relative chlorophyll content of peach leaves. Melatonin inhibited the production of H_(2)O_(2) and malondialdehyde(MDA), also enhanced the activities of antioxidant enzymes, thereby alleviating the oxidative damage of drought to peach seedlings. Drought increased the expression levels of stress response genes as DREB1 A, DREB2 A, LEA and PIP1. Melatonin can further increase the expression level of related genes to promote the adaptability of peach seedlings to drought environment. Melatonin treatment has a dose effect, and the effect of medium and low concentrations(100-200 μmol·L^(-1)) are more obvious.

关 键 词：桃苗 干旱胁迫 褪黑素 抗氧化 基因表达 

分 类 号：S662.1[农业科学—果树学]