Phytohormonal modulation alleviates arsenic toxicity in rice by enhancing antioxidant defenses, proline metabolism, and arsenic detoxification mechanisms

Utilizing phytohormones-brassinosteroids (BRs), jasmonic acid (JA), and strigolactones (SLs) presents a novel approach to overcome toxicity of arsenic (As) in agricultural settings. The present study investigates the role of three phytohormones BRs, JA, and SLs in ameliorating As-induced stressed in Oryza sativa L. (rice) seedlings. s In the present study, we have used different levels of BRs (0.1 µM), JA (1 µM), and SLs (0.05 µM) every 7 days to O. sativa seedlings when exposed to different levels of As levels of 100 mg^-1 kg and 200 mg kg^-1 (as sodium arsenate) to examine various growth and biochemical parameters in O. sativa. The results showed that the As toxicity in the soil showed a significantly (P < 0.05) declined in the growth, gas exchange attributes, sugars, AsA-GSH cycle, cellular fractionation, proline metabolism in O. sativa. However, As toxicity significantly (P < 0.05) increased oxidative stress biomarkers, enzymatic and nonenzymatic antioxidants including their gene expression in O. sativa. Although, the application of phytohormones including BRs, JA, and SLs showed a significant (P < 0.05) increase in the plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds and their gene expression and also decreased the oxidative stress, and As uptake. In addition, individual or combined application of phytohormones including BRs, JA, and SLs enhanced the cellular fractionation and decreases the proline metabolism and AsA - GSH cycle in O. sativa. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils.