BAK1 (brassinosteroid-insensitive 1 (BRI1) associated receptor kinase 1) plays major roles in multiple signaling pathways as a coreceptor to regulate plant growth and development and stress response. However, the role of BAK1 in high light signaling is still poorly understood. Here we observed that overexpression of BAK1 in Arabidopsis interferes with the function of high light in promoting plant growth and development, which is independent of the brassinosteroid (BR) signaling pathway. Further investigation shows that high light enhances the phosphorylation of BAK1 and catalase activity, thereby reducing hydrogen peroxide (H₂O₂) accumulation. Catalase3 (CAT3) is identified as a BAK1-interacting protein by affinity purification and LC-MS/MS analysis. Biochemical analysis confirms that BAK1 interacts with and phosphorylates all three catalases (CAT1, CAT2, and CAT3) of the Arabidopsis genome, and the trans-phosphorylation sites of three catalases with BAK1-CD are identified by LC-MS/MS in vitro. Genetic analyses reveal that the BAK1 overexpression plants knocked out all the three CAT genes completely abolishing the effect of BAK1 on suppression of high light-promoted growth. This study first unravels the role of BAK1 in mediating high light-triggered activation of CATs, thereby degrading H₂O₂ and regulating plant growth and development in Arabidopsis.

Global agricultural productivity and ecosystem sustainability face escalating threats from multiple abiotic stresses, particularly heavy metal contamination, drought, and soil salinization. In this context, developing effective strategies to enhance plant stress tolerance has emerged as a critical research frontier. Phosphate-solubilizing microorganisms (PSMs) have garnered significant scientific attention due to their capacity to convert insoluble soil phosphorus into plant-available forms through metabolite production, and concurrently exhibiting multifaceted plant growth-promoting traits. Notably, PSMs demonstrate remarkable potential in enhancing plant resilience and productivity under multiple stress conditions. This review article systematically examines current applications of PSMs in typical abiotic stress environments, including heavy metal-polluted soils, arid ecosystems, and saline–alkaline lands. We comprehensively analyze the stress-alleviation effects of PSMs and elucidate their underlying mechanisms. Furthermore, we identify key knowledge gaps and propose future research directions in microbial-assisted phytoremediation and stress-mitigation strategies, offering novel insights for developing next-generation bioinoculants and advancing sustainable agricultural practices in challenging environments.