The role of phytohormones in reducing the arsenic-induced stress in plants

Arsenic (As) toxicity in crops is a major global concern, adversely affecting sustainable agricultural practices, and serving as a potential carcinogenic pollutant. As contamination in soil poses a significant threat to plant health and productivity, adversely impacting growth, photosynthesis, and the antioxidant system. To address this issue, plants endogenously regulate the levels of various phytohormones, and the exogenous application of phytohormones to mitigate As-induced stress has gained significant attention. Phytohormones act as secondary (2°) messengers, participating in diverse signaling cascades under As stress. As uptake in plants leads to the As-accumulation and generation of excessive reactive oxygen species (ROS) which can be alleviated by phytohormones. Numerous studies have highlighted the role of phytohormones, such as auxins, methyl jasmonates, salicylic acid, brassinosteroids, and Mel, in regulating pathways that enhance plant growth, biomass accumulation, ROS scavenging, antioxidative enzyme and photosynthesis under As stress. This review summarizes the detailed mechanism of As phytotoxicity, its detoxification mechanism, and the exogenous application of phytohormones to alleviate As stress. Additionally, we provide insights into recent findings on the possible roles of various genes, proteins, transgenic factors, and genome editing approaches in phytohormone-mediated As-stress tolerance.