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采用温室盆栽试验,研究了不同浓度(0、20、40、60、80、100 mg·L-1)的外源抗坏血酸(AsA)与谷胱甘肽(GSH)对50 mg·kg-1镉(Cd)胁迫下石竹幼苗生长的影响.结果表明:50 mg·kg-1Cd显著抑制了石竹幼苗的生长,适宜浓度的外源AsA能够缓解Cd对石竹幼苗生长的胁迫,显著提高其生物量、株高、分蘖数、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)等抗氧化酶活性,以及AsA和GSH含量,但随着外源AsA浓度的增加,缓解效应下降,甚至产生促氧化效应;外源GSH可以及时补充Cd胁迫下石竹幼苗体内的非酶抗氧化剂,但抗氧化酶活性变化相对较小,其缓解Cd毒害的主要机制可能是促进根系中金属螯合肽(PCs)的合成,增加其与Cd的螯合,从而降低石竹幼苗体内Cd含量.研究表明,35~45mg·L-1的外源AsA和55~65 mg·L-1的外源GSH都能很好地缓解石竹幼苗Cd毒害,且前者效果优于后者.
Pot experiments were conducted to study the effects of different concentrations of AsA and GSH on the activity of 50 mg · kg -1 cadmium (Cd) stress on the growth of Dianthus chinensis seedlings.The results showed that: 50 mg · kg-1Cd significantly inhibited the growth of Dianthus chinensis seedlings, suitable concentrations of exogenous AsA can alleviate the Cd stress on the growth of Dianthus cocos, significantly increase its biomass, Plant height, tiller number, catalase (CAT) and ascorbate peroxidase (APX), as well as the content of AsA and GSH, but with the increase of exogenous AsA concentration, the alleviating effect decreased and even occurred (GSH) could replenish the non-enzymatic antioxidants of Dianthus chinensis seedling under cadmium stress in a timely manner, but the changes of antioxidant enzyme activities were relatively small. The main mechanism of mitochondrial toxicity could be to promote the accumulation of metal chelating peptides (PCs ) To increase its chelation with cadmium, thus reducing the content of Cd in Dianthus chinensis seedlings.The results showed that 35 ~ 45 mg · L-1 of exogenous AsA and 55 ~ 65 mg · L-1 of exogenous GSH can be very Good to alleviate the Dianthus seedling Cd toxicity, and the former is better than the latter.