外源乙酸对水稻幼苗根系干旱胁迫的缓解效应

Effect of exogenous acetic acid on alleviating drought stress in the roots of rice seedlings

本实验对培养至一叶一心期的水稻(Oryza sativa)幼苗进行干旱胁迫处理,通过对比不同处理间的过氧化指标、抗氧化酶活性和抗氧化酶基因表达,探索外源乙酸(HAc)对干旱条件下水稻幼苗抗氧化系统的调节作用。结果发现,外源HAc不同程度地提高了干旱下水稻幼苗根部超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)的活性及对应编码基因表达水平,同时显著降低了膜透性、丙二醛(MDA)含量以及超氧阴离子(O2ˉ)和过氧化氢(H2O2)等的含量。结果表明,外源HAc可以通过上调抗氧化酶编码基因表达水平调节抗氧化酶活性,缓解干旱胁迫对水稻幼苗造成的损伤,提高其抗旱性。

In present study,rice(Oryza sativa)seedlings were treated with 20%polyethylene glycol-6000(PEG)at the stage of one-leaf-one-plant.Then we explored the effect of exogenous acetic acid(HAc)on the antioxidant system of rice seedlings subjected to drought stress through comparing peroxidation indices,the activity levels and gene expression levels of antioxidant enzymes.The results show that HAc significantly decreased the contents of malondialdehyde(MDA),superoxide anion(O2ˉ)and hydrogen peroxide(H2O2),whereas increased the activities and gene expression levels of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD)and ascorbate peroxidase(APX),and reduced membrane permeability in the rice seedling roots under drought stress.Therefore,HAc may improve the resistance against drought stress via enhancing the antioxidant capability of roots in the rice seedlings.