Fang Li-Rong, Ren Jing-Yu, Sun Kai, Zhang Wei, He Wei, Dai Chuan-Chao
College of Life Sciences, Nanjing Normal University, Wenyuan street, Nanjing 210023, China.
J Appl Microbiol. 2025 Feb 3;136(2). doi: 10.1093/jambio/lxaf022.
This study was dedicated to investigating the role of sulfur metabolic processes in sulfate-reducing bacteria in plant resistance to heavy metal contamination.
We constructed sulfate-reducing bacterial communities based on the functional properties of sulfate-reducing strains and then screened out the most effective sulfate-reducing bacterial community SYN1, that prevented Cd and Pb uptake in rice through a hydroponic experiment. This community lowered Cd levels in the roots and upper roots by 36.60% and 39.88%, respectively, and Pb levels by 35.96% and 51.54%. We also compared two treatment groups, inoculated with SYN1 and exogenously added GSH, and found that both enhanced the antioxidant response of the plants, increased the lignin and GSH contents and the expression of genes related to the phenylpropane biosynthesis pathway (OsCAD, Os4CL, OsCOMT, OsPOD, OsC3H, and OsPAL), and decreased the expression of heavy metal transporter genes (OsHMA2, OsIRT1) expression. There were no significant differences between the two treatments.
Sulfate-reducing bacteria produce GSH through the sulfur assimilation pathway, and GSH can directly chelate heavy metals or enhance plant antioxidant enzyme activities and regulate processes such as the uptake and translocation of heavy metals, thus enhancing plant resistance to heavy metal toxicity.
本研究致力于探究硫酸盐还原菌中的硫代谢过程在植物对重金属污染抗性中的作用。
我们基于硫酸盐还原菌株的功能特性构建了硫酸盐还原细菌群落，然后通过水培实验筛选出了最有效的硫酸盐还原细菌群落SYN1，该群落可防止水稻吸收镉和铅。该群落使水稻根部和地上部的镉含量分别降低了36.60%和39.88%，铅含量分别降低了35.96%和51.54%。我们还比较了接种SYN1和外源添加谷胱甘肽（GSH）的两个处理组，发现二者均增强了植物的抗氧化反应，增加了木质素和GSH含量以及与苯丙烷生物合成途径相关基因（OsCAD、Os4CL、OsCOMT、OsPOD、OsC3H和OsPAL）的表达，并降低了重金属转运蛋白基因（OsHMA2、OsIRT1）的表达。两种处理之间无显著差异。
硫酸盐还原菌通过硫同化途径产生GSH，GSH可直接螯合重金属或增强植物抗氧化酶活性，并调节重金属的吸收和转运等过程，从而增强植物对重金属毒性的抗性。
