不同抗旱性小麦品种对干旱胁迫的响应及NO的调节作用

The Response of Different Drought-resistance of Wheat Varieties under Drought Stress and the Regulating Role of Nitric Oxygen

[目的]研究不同抗旱性小麦品种对干旱胁迫的响应机制,并探明外源NO对干旱胁迫下小麦叶片氧化损伤及光合机构的保护作用。[方法]以低抗品种预麦949和高抗品种峡麦5号为试验材料,用15%PEG-6000对五叶期幼苗模拟干旱胁迫,然后使用0.75mmol/LSNP(硝普钠,外源NO供体)进行调节,并测定体内抗氧化和光合活性。试验设置3个处理。[结果]高抗品种峡麦5号的SOD、CAT和APX活性,MDA含量和叶绿素含量均比高产低抗品种预麦949高;在干旱胁迫下,高抗品种的这些生理指标变化幅度小于高产低抗品种;同时,NO显著提高了这些生理指标对干旱胁迫的适应性。[结论]外源NO能够提高干旱胁迫下小麦叶片抗氧化酶的活性,增强小麦的抗旱性。

[Objective]The aim was to study the response mechanism of drought stress of wheat varieties in different drought-resistance species,and protect the effection of exogenous NO on oxidative damage and photosynthetic apparatus of wheat leaves under drought stress.[Method]Using low-resistance Yumai 949 and high-resistance Xiamai 5 as test materials,drought stress was carried out to seedlings in five-leaf stage with 15% PEG-6 000,and then NO（0.75 mmol/L SNP,sodium nitroprusside,exogenous NO donor）was used for regulation in drought condition,and antioxidant and photosynthetic activities was determined.Three treatments were set in the experiment.[Result] SOD,CAT and APX activities of high-resistance Xiamai 5 were much higher than low resistance Yumai 949,so were MDA and chlorophyll content.And the change range of these physiological indexes of high resistance species was smaller than high-yielding and low resistance species under drought stress.NO increased the adaptation to drought stress of these physiological indexes significantly.[Conclusion] Exogenous NO could increase the activity of antioxidant enzymes of wheat leaves under drought stress,and enhance the drought resistance of wheat.