硫化氢调节谷子幼苗P-ATPase响应镉胁迫

Hydrogen sulfide regulates cadmium stress resistance through P-ATPases in foxtail millet seedlings

为了研究H_2S对谷子幼苗中ATPases活性的影响及其与金属转运蛋白HMAs基因表达调控的关系,以及H_2S对谷子幼苗细胞内Cd离子的解毒作用。在Cd胁迫条件下,对可溶性糖和可溶性蛋白以及ATPase活性进行测定,对谷子HMA家族转运蛋白进行系统进化分析并对H_2S对转运蛋白HMAs转录水平的影响进行分析。结果表明,在Cd胁迫条件下,谷子幼苗的可溶性糖和可溶性蛋白含量降低,ATPase活性被抑制,同时HMA家族基因表达量升高;H_2S处理可使可溶性糖含量提高的同时增强ATPase的活性,此外HMA的基因表达量也有相应变化。研究表明,硫化氢可以调节谷子幼苗P-ATPase的表达和活性,进而缓解Cd胁迫对谷子幼苗的毒害作用。

Hydrogen sulfide（H2 S）, a newly found gasotransmitter, has been shown to play crucial roles in the development of plants, as well as in their resistance to various biotic or abiotic stresses. Cadmium is one of the heavy metals that are highly toxic to the growth of plants. In this study, the relationship among the exogenous H_2 S, the activity of key ATPases, and the expression levels of heavy metal ATPase（HMA）genes, which encode a class of metal transporters, was analyzed under Cd stress conditions, and the mechanism to relieve Cd toxicity in foxtail millet was eventually determined. We determined the contents of soluble sugar and proteins and the activities of ATPases in the foxtail millet seedlings growing under Cd stress conditions. Additionally, the phylogenetic analysis of HMA proteins and the expression level analysis of the HMA genes were carried out under the exogenous application of H2 S and Cd. In the seedlings growing under Cd stress, the contents of soluble sugars and proteins were decreased, the activity of ATPases（Ca^2＋-ATPase, Mg^2＋-ATPase, and H^＋-ATPase）were inhibited, and the expression levels of HMA genes in the P1 B-ATPase family were increased. The H2 S treatment could increase the content of soluble sugar and the activities of three kinds of ATPases, upregulate the expression levels of HMA1 and HMA2, and down regulate the expression level of HMA3. These results showed that H_2 S could regulate the activities of P-ATPases to alleviate Cd stress in foxtail millet seedlings.