Wu Yingjie, Zhao Haiyang, Xiao Meijuan, Liu Huimin, He Hua, Peng Lu, Tao Qi, Tang Xiaoyan, Zhang Yanyan, Huang Rong, Li Bing, Wang Changquan
College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
College of Resources, Sichuan Agricultural University, Chengdu 611130, China.
J Hazard Mater. 2025 Feb 15;484:136795. doi: 10.1016/j.jhazmat.2024.136795. Epub 2024 Dec 4.
Cadmium (Cd) is easily absorbed by rice and enters the food chain, posing a health risk to humans. Plant growth promoting bacteria (PGPB) can help the plant respond to Cd stress, but the mechanism of PGPB for Cd reduction is unclear. Therefore, this study was conducted and found inoculation with a newly isolated Pseudomonas koreensis promoted the growth of rice and reduced its Cd content. Fluorescent staining using PI and HO probe indicated that PGPB attenuated oxidative damage in rice. Metabolomics revealed that 59 metabolites were upregulated after inoculation, with phenylpropanoids and flavonoids being significantly activated. Spectrophotometry analysis comfirmed the content of flavonoid, lignin, phenol, glutathione, proline and the activities of antioxidant enzymes were higher in the inoculated rice than in the control. Quantitative PCR showed the expression of genes related to phenylpropanoids (OsPAL, OsC4H, Os4CL) and flavonoids (OsCHS, OsCHI) was significantly increased by PGPB, while the genes of heavy metal transporters (OsNRAMP5, OsHMA2, OsIRT1) were significantly decreased. Overall, this study provides an insight into the PGPB-mediated detoxification mechanism in rice under Cd stress and emphasizes the role of phenylpropanoids and flavonoids in the production of low-Cd rice to ensure human health.
镉（Cd）很容易被水稻吸收并进入食物链，对人类健康构成风险。植物促生细菌（PGPB）可以帮助植物应对镉胁迫，但其降低镉含量的机制尚不清楚。因此，开展了本研究，发现接种新分离的韩国假单胞菌可促进水稻生长并降低其镉含量。使用PI和HO探针进行的荧光染色表明，PGPB减轻了水稻的氧化损伤。代谢组学显示，接种后有59种代谢物上调，其中苯丙烷类和黄酮类被显著激活。分光光度法分析证实，接种水稻中黄酮类、木质素、酚类、谷胱甘肽、脯氨酸的含量以及抗氧化酶的活性均高于对照。定量PCR显示，PGPB显著增加了与苯丙烷类（OsPAL、OsC4H、Os4CL）和黄酮类（OsCHS、OsCHI）相关基因的表达，而重金属转运蛋白（OsNRAMP5、OsHMA2、OsIRT1）的基因则显著减少。总体而言，本研究深入了解了镉胁迫下PGPB介导的水稻解毒机制，并强调了苯丙烷类和黄酮类在生产低镉水稻以确保人类健康方面的作用。
