6-BA对Hg2+胁迫下小麦幼苗渗透调节物质及抗氧化特性的影响

为探讨6-苄氨基腺嘌呤(6-BA)对Hg2+胁迫下小麦幼苗生长的调节作用,采用营养液水培法,以小麦品种807为材料,分析了叶面喷施不同浓度的6-BA对Hg2+胁迫下小麦幼苗叶片中渗透调节物质含量、抗氧化酶活性及抗氧化物质含量的影响。结果表明,50mg·L-1 HgCl2处理后,小麦幼苗叶片的可溶性糖和可溶性蛋白含量显著降低,过氧化物酶(POD)和超氧化物歧化酶(SOD)活性下降,还原型抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量显著降低。叶面喷施一定浓度的6-BA能够提高Hg2+胁迫下小麦幼苗叶片的可溶性糖和可溶性蛋白含量,显著提高小麦幼苗叶片的POD、SOD活性和AsA、GSH含量,降低脱氢抗坏血酸(DHA)和氧化型谷胱甘肽(GSSG)含量,提高小麦幼苗叶片的AsA/DHA和GSH/GSSG比值,从而缓解Hg2+胁迫对小麦幼苗生长的抑制作用。叶面喷施10mg·L-1 6-BA对缓解小麦幼苗Hg2+胁迫效果最好。

Effect of 6-BA on the Osmotic Adjustment Substance and Antioxidant Properties in Wheat Seedlings under Hg2+ Stress

To investigate the regulation effects of 6-BA on the resistance of wheat seedlings to Hg²⁺, wheat cultivar 807 used as experimental material, a nutrient solution-cultured experiment was conducted to study the effects of 6-BA on the osmotic adjustment substance content, the antioxidant enzyme activity and the antioxidants content in wheat seedling leaves under Hg²⁺ stress. The results showed that treated wheat seedlings with 50 mg·L^-1 HgCl₂, the soluble sugar and soluble protein content decreased, the peroxidase(POD) and superoxide dismutase (SOD) activity declinned, the ascorbic acid (AsA) and glutathione(GSH) content decreased in wheat seeding leaves.Compared with Hg²⁺ stress alone, certain concentration of 6-BA sprayed to wheat seedling could improve the contents of soluble sugar and soluble protein, increase the activities of POD and SOD, enhance the contents of AsA and GSH, decrease the contents of DHA and GSSG, increase the ratio of AsA/DHA and GSH/GSSG of wheat seedling leaves.Suggesting that certain concentration of 6-BA could mitigated the harmful effects of Hg²⁺ stress on wheat seedlings, the optimal 6-BA concentration was 10 mg·L^-1.