MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resources Sciences, Zhejiang University, Hangzhou 310058, PR China.
Chemosphere. 2016 Jul;154:358-366. doi: 10.1016/j.chemosphere.2016.03.120. Epub 2016 Apr 8.
A hydroponic experiment was conducted to verify the effects of inoculation with endophytic bacteria Sphingomonas SaMR12 on root growth, cadmium (Cd) uptake, reactive oxygen species (ROS), antioxidases, glutathione (GSH) and the related gene expression of Sedum alfredii Hance under different levels of Cd such as 0, 10, 25, 100 and 400 μM. The results showed that inoculation of SaMR12 improved Cd accumulation and upregulated glutathione synthase (GS) expression, but slightly reduced malondialdehyde (MDA) concentration and alleviated Cd-induced damage in roots. However it didn't alter the activities of antioxidant enzymes. When Cd concentration exceeded 25 μM, SaMR12 increased the concentration of GSH and the expression level of GSH1. At high Cd treatment levels (100 and 400 μM), SaMR12 significantly reduced H2O2 concentration and enhanced expression level of 1-Cys peroxiredoxin PER1 and ATPS genes. These results indicate that although SaMR12 has no significant effects on antioxidases activities, it reduces H2O2 concentration by enhancing GSH concentration and relevant genes expression, and subsequently improves Cd tolerance and accumulation.
进行了一项水培实验，以验证内生细菌 Sphingomonas SaMR12 接种对不同浓度 Cd（0、10、25、100 和 400 μM）条件下Sedum alfredii Hance 根系生长、镉吸收、活性氧（ROS）、抗氧化酶、谷胱甘肽（GSH）和相关基因表达的影响。结果表明，SaMR12 接种提高了 Cd 积累并上调了谷胱甘肽合酶（GS）表达，但轻微降低了丙二醛（MDA）浓度并减轻了 Cd 对根系的损伤。然而，它并未改变抗氧化酶的活性。当 Cd 浓度超过 25 μM 时，SaMR12 增加了 GSH 的浓度和 GSH1 的表达水平。在高 Cd 处理水平（100 和 400 μM）下，SaMR12 显著降低了 H2O2 浓度并增强了 1-Cys 过氧化物酶 PER1 和 ATPS 基因的表达水平。这些结果表明，尽管 SaMR12 对抗氧化酶活性没有显著影响，但通过增强 GSH 浓度和相关基因表达降低了 H2O2 浓度，从而提高了 Cd 耐受性和积累。
