谷胱甘肽对小麦幼苗铜毒害的缓解作用及其与氮、硫、磷积累的相关性

Effects of Glutathione on Alleviation of Copper Toxicity and Its Correlation with Accumulation of Nitrogen,Sulfur and Phosphorus in Wheat Seedlings

采用水培法,对外源谷胱甘肽(GSH)缓解小麦幼苗铜毒害及其与氮、硫、磷等元素积累的相关性进行了研究。结果表明,Cu处理(T0组)显著抑制小麦幼苗的生长发育,导致根长、茎叶长、生物量、叶绿素和类胡萝卜素含量以及氮元素积累量下降,诱导了植株蛋白质、内源GSH含量以及硫、磷元素积累量上升。随施用外源GSH浓度的升高,GSH处理(T1、T2、T3组)的小麦幼苗茎叶长、根长、生物量,叶绿素a、b和类胡萝卜素含量、蛋白质含量先上升后下降,内源GSH含量以及氮、硫、磷等营养元素积累量持续上升;其中,T2组小麦幼苗的各项指标与T0组差异均达到显著水平(P<0.05),与对照组(CK)无显著差异。外源GSH促进了植株对铜离子的吸收、转运和积累,而外源和内源GSH均与铜胁迫下小麦幼苗氮、硫、磷等营养元素的积累呈极显著正相关(P<0.01),其中以T2处理组缓解小麦幼苗铜毒害的作用最显著。

The effects of exogenous glutathione on alleviation of copper toxicity and its correlation with contents of nitrogen, sulfur and phosphorus in wheat seedlings stressed by copper sulfate were studied in a hydroponic culture. The results indicated that wheat seedlings growth, stem and root length, biomass, chlorophyll and carotenoids contents, nitrogen accumulation were inhibited by CuSO4 7H2O treatment at 150 mg L-1 concentration, whereas protein, endogenous GSH, sulfur and phosphorus contents were raised. The length of stem and root, biomass, chlorophyll a, b, carotenoids and protein contents increased with the increase of exogenous GSH until the GSH was 2.5 mmol. L-1, and then decreased. Meanwhile, endogenous GSH content as well as nitrogen, sulfur, phosphorus accumulation rised up. There was a significant differ- ence between T2 and TO treatment, but there was no such difference with control. In general, exogenous GSH could promote absorbing, trans- porting, and accumulating of copper in wheat seedlings. Exogenous and endogenous GSH remarkably improved accumulation of nitrogen, sulfur, phosphorus under copper stress （P〈0.01）. T2 treatment exhibited the highest level of alleviation of copper toxicity in wheat seedlings.