The regulation and mechanism of Rhodotorula mucilaginosa for the growth and antimony accumulation of rice under antimony stress

Antimony (Sb), a toxic and potentially carcinogenic element, can readily accumulate in rice, posing challenges to both food safety and agricultural production. Building upon the previous study on the highly antimony-tolerant fungus Rhodotorula mucilaginosa (R. mucilaginosa), this study systematically evaluated its potential to reduce antimony accumulation in rice and promote rice growth through pot experiments. The results demonstrated that R. mucilaginosa inoculation not only reduced antimony accumulation in rice but also promoted rice growth under antimony stress. The growth promoting effects of R. mucilaginosa on rice mainly contribute to its growth-promoting properties and its regulatory function on the abundance of rhizosphere fungi related to photosynthesis, which synergistically enhance the absorption of nutrients and increase rice yield. The mechanism by which R. mucilaginosa reduces antimony accumulation in rice mainly lies in its inhibition function for the formation of Fe-Mn oxide-bound antimony and its facilitation function for the formation of sulfide and residual-bound antimony. In conclusion, R. mucilaginosa exhibits significant potential for the remediation of antimony-polluted farmland by effectively curbing antimony accumulation in crops and promoting crop growth under antimony stress. This finding provides a theoretical foundation and technical approach for microbial remediation of antimony-contaminated soils.