硝酸镧对干旱下冬小麦幼苗抗坏血酸和谷胱甘肽代谢的影响

Effects of lanthanum nitrate on ascorbate and glutathione metabolism of winter wheat seedlings under drought stress

以冬小麦百农207为材料,利用10%PEG6000模拟干旱胁迫,研究硝酸镧对干旱下小麦抗坏血酸和谷胱甘肽代谢的影响.结果表明:干旱显著提高了冬小麦幼苗MDA含量和膜透性,并显著降低了抗坏血酸和谷胱甘肽氧化还原状态,这说明干旱对冬小麦幼苗造成了过氧化伤害.外源不同浓度硝酸镧处理均显著提高了干旱下抗坏血酸和谷胱甘肽循环代谢酶APX和GR及合成代谢酶GalLDH和γ-ECS活性,进而显著提高了抗氧化物质AsA和GSH含量以及抗坏血酸和谷胱甘肽氧化还原状态,从而显著降低了MDA含量和膜透性.除100μmol/L硝酸镧外,其他浓度的硝酸镧均显著提高了干旱下抗坏血酸和谷胱甘肽循环代谢酶DHAR和MDHAR活性,从而进一步提高了冬小麦抵御干旱的能力.研究结果表明,外源硝酸镧可以增强抗坏血酸和谷胱甘肽代谢合成和循环代谢,从而缓解干旱对冬小麦造成的过氧化伤害.

In this paper,the effects of lanthanum nitrateon ascorbate and glutathionemetabolism of wheat under drought stress induced by 10%PEG by using winter wheat Bainong207 as materials.The results showed that drought stress significantly increased MDA content and membrane permeability and reduced the redox states of ascorbate and glutathione,which indicated thatdrought stress induced peroxide injury to winter wheat seedlings.All the treatments of different concentrations of lanthanum nitrate significantly increased the activities of ascorbate and glutathione circulating metabolic enzymesAPX and GR and anabolic enzymes GalLDH andγ-ECS,which,in turn,significantly improved the contents of antioxidants AsA and GSH and the redox states of ascorbate and glutathione.By this way,lanthanum nitrate significantly reduced MDA content and membrane permeability.Except 100μmol/L lanthanum nitrate,other concentrations of lanthanum nitrate all significantly increased ascorbate and glutathione circulating metabolic enzymes DHAR and MDHAR,which further improved winter wheat's ability to fight against drought stress.Above results indicated that exogenous lanthanum nitrate alleviatedthe peroxidation damage of winter wheat caused by drought by enhancing the biosynthesis and cyclic metabolism of ascorbate and glutathione.