甜高粱幼苗对Cr^(6+)胁迫的生理响应研究

Study on Physiological Response of Sweet Sorghum Seedlings to Cr^(6+) Stress

以甜高粱为试材,研究了不同浓度(0、0.5、1.0和1.8 mmol/L)K2CrO4处理对甜高粱幼苗生物量,非酶系统GSH和AsA含量,以及抗氧化酶系统酶活性的影响。结果表明:与CK(0 mmol/L)相比,低浓度(0.5 mmol/L)的Cr6+胁迫能够明显促进甜高粱幼苗生长;而中(1.0 mmol/L)、高(1.8 mmol/L)浓度的Cr6+胁迫会对甜高粱幼苗生长产生极强烈的抑制作用,地上部干重、根干重和总干重均极显著<CK。抗氧化酶系统中,不同浓度的Cr6+胁迫下,SOD、POD、CAT和APX活性表现不尽相同,与CK相比,低浓度的Cr6+胁迫,对幼苗叶片O2.-产生速率、H2O2含量以及SOD、POD和APX活性均无显著影响;中浓度Cr6+胁迫下,叶片O2.-产生速率、H2O2含量以及4种酶的活均较CK显著提高;随着Cr6+浓度的进一步增大,POD活性进一步增强,APX活性在一定程度上略有下降,而SOD和CAT活性均较CK显著降低。非酶系统中,随着Cr6+处理浓度的增大,甜高粱幼苗叶片AsA和GSH含量均呈先升高后降低的变化趋势,但所有浓度Cr6+处理的AsA含量均>CK,而GSH含量在高浓度胁迫下显著<CK。总体来看,甜高粱幼苗对Cr6+胁迫响应积极,且表现出一定的耐受性。

Using sweet sorghum as the test material, the biomass, enzyme activities of antioxitant enzyme system and the GSH and AsA contents of non-enzymatic system on sweet sorghum seedlings under Cr6＋ （0, 0. 5, 1.0, 1.8 mmol/L K2 CrQ ） stress were studied. The results showed that compared with the control （0 retooL/L）, low concentration （0. 5 retool/L） of Cr6＋ promoted the growth of seedlings obviously, while it caused the strong inhibition when concentrations of Cr6＋ were 1.0 mmol/L and 1.8 mmol/L, and the shoot dry weight, root dry weight and total dry weight of which were significantly dropped than CK. In antioxidant enzyme system, the changes of SOD, POD, CAT and APX activity were different under the different concentrations of Cr6 ＋ stress compared with CK. The O2·- production rate, H2O2 content and SOD, POD and APX activity had no significant effect under lower concentrations of Cr6＋ stress on seedling leaves. With the 1.0 mmol/L of Cr6＋ O2 ·- production rate, H2O2 content, activities of SOD, CAT, APX and POD were increased significantly, the activity of POD was increased significantly, and the activity of APX was decreased slightly in some extent with the increasing of the concentration of Cr6＋ , while SOD and CAT activity were significantly lower than CK. Content trend of GSH and AsA were firstly increased and then decreased in non-enzyme antioxitant substance, AsA content was more than CK in all the concentrations of Cr6＋ , but GSH content was lower than that of the control under 1 . 8 mmol / L of Cr6 ＋ . Sweet sorghum seedlings made an active response to the Cr6＋ stress and had certain toleration to the Cr6＋ stress.