干旱胁迫下褪黑素对小麦幼苗生长、光合和抗氧化特性的影响  

Effects of Melatonin on Growth,Photosynthetic Characteristics and Antioxidant System in Seedling of Wheat under Drought Stress

作　　者：叶君[1,2] 邓西平[1,3] 王仕稳[1,3] 殷俐娜[1,3] 陈道钳 熊炳霖 王鑫月[1,2] 

机构地区：[1]中科院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室 [2]中国科学院大学,北京100049 [3]西北农林科技大学水土保持研究所,陕西杨凌712100 [4]西北农林科技大学生命科学学院,陕西杨凌712100

出　　处：《麦类作物学报》2015年第9期1275-1283,共9页Journal of Triticeae Crops

基　　金：国家重点基础研究发展计划项目(2015CB150402);国家自然科学基金项目(51479189);中科院西部之光项目

摘　　要：为探究褪黑素对小麦幼苗抗旱性的调节作用,明确褪黑素提高小麦抗旱能力的作用途径,以小麦水地品种西农9871为材料,通过盆栽试验,分析了干旱胁迫下根施褪黑素(100μmol·L-1)对小麦幼苗生长、光合特性及活性氧代谢的影响。结果表明,干旱胁迫抑制了小麦的生长,降低了叶片叶绿素含量、气孔导度、净光合速率及PSⅡ最大光化学效率,导致过氧化氢(H2O2)与丙二醛(MDA)积累增加及抗氧化酶活性、抗氧化剂含量升高。在干旱胁迫下根施褪黑素可增加小麦幼苗的生物量和根冠比,维持较高的相对叶片含水量、叶绿素含量、净光合速率及光化学效率,并进一步提高过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、过氧化物酶(POD)活性及抗坏血酸(ASA)和谷胱甘肽(GSH)的含量,减少了H2O2与MDA的积累。复水后,根施褪黑素处理的小麦幼苗生长表现出较快的恢复能力。以上结果说明,在干旱胁迫下,褪黑素通过增加根冠比,促进水分吸收,改善叶片的水分状况,并通过增强抗氧化能力,减轻氧化伤害。褪黑素处理的植株表现出较好的水分状况和较轻的氧化伤害,有利于其维持较高的光合能力,从而提高小麦幼苗的抗旱性及恢复生长的能力。The objective of the study is to reveal the effects of melatonin（MEL） on wheat seedlings growth under drought stress. A winter wheat（Triticurn aestivum L. ） cultivar,Xinong 9871（droughtsensitive） ,was selected as the experimental material and was planted in pot under soil conditions. Melatonin（100 μmol · L^-1）was applied to the soil. The effects of MEL on wheat seedling growth, the photosynthetic characteristics and active oxygen metabolism were investigated. Results showed that drought stress inhibited the seedling growth, decreased the chlorophyll content, stomatal conductance, net photosynthetic rate and maximum PS Ⅱ quantum yield; resulted in H2O2 and MDA accumulation; and enhanced the activity of antioxidant enzymes and antioxidant content. Under drought stress condition,MEL application increased the biomass and root-shoot ratio; maintained a higher level in RWC, chlorophyll content,net photosynthetic rate and the photochemical efficiency; increased the activity of CAT, APX,POD and AsA, GSH content; and reduced the H2O2 and MDA accumulation. After re-watering,the wheat seedlings with MEL application recovered growth quickly. This study indicated that MEL application increased the root-shoot ratio under drought stress; promoted the water absorption; improved leaf water status; enhanced antioxidant capacity; and alleviated the active oxygen damage. Melatonin-treated plants showed a well water status and slight oxidative damage,which was contributed to maintain higher photosynthetic rate,so as to improve the wheat drought tolerance.

关 键 词：褪黑素 小麦 幼苗 干旱胁迫 光合生理 活性氧代谢 

分 类 号：S512.1[农业科学—作物学] S311