Food security through triacontanol priming: Mitigating chromium stress and boosting yield in <i>Raphanus sativus</i> L.

A major global concern for food security and human health is the indiscriminate discharge and consequent accumulation of heavy metals from various anthropogenic sources into the environment. Chromium (Cr) is one of the most common toxic effluents that pollute agricultural soil. Chromium intake affects plant metabolism, photosynthetic activity, growth, and productivity. In the present study, triacontanol (TRI) was exogenously supplied via seed priming and foliar spraying (10 ppm and 20 ppm) to alleviate Cr (60 mg/kg) stress in Raphanus sativus L. (radish). Chromium reduced shoot length by 65.21%, roots length by 66.28%, gas exchange attributes by 36.23%, mineral content by 52.55%, and phenol content by 11.11%, but the ascorbic acid content increased by 43.23%. Moreover, 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity increased by 26.34%, which reduced the degree of oxidative damage caused by Cr. Additionally, elevated nutritional contents (Zn+2, Mg+2, K+, and Na+), total photosynthetic pigments (34.42%) and proline contents were correlated with relatively higher levels of ascorbic acid. Interestingly, exogenous TRI administration reduced the oxidative damage caused by Cr. In general, our findings demonstrated that seed priming and foliar supplementation with TRI improved R. sativus plant’s tolerance to Cr by reducing its accumulation and restoring oxidative equilibrium.