Taurine protected Trifolium alexandrinum L. plants from damages of individual and interactive effects of chromium and drought stress

Taurine functions as an essential ROS scavenger and thereby diminishes lipid peroxidation of biomembranes. Taurine also regulates osmoregulation. However, nothing is known about how taurine mediates plant defense mechanisms under drought and chromium (Cr) stress. Trifolium alexandrinum plants were exposed to individual and combined drought and Cr conditions. We have noticed a substantial decline in growth, photosynthetic pigments, SPAD values, and acquisition of essential nutrients. Further, the reduction in these attributes was more noteworthy in plants under combined Cr and drought conditions. The results also revealed a significant increase in oxidative damage reflected as a higher generation of reactive oxygen species, malondialdehyde, and enhanced lipoxygenase activity. The oxidative injury was more remarkable in plants under combined Cr and drought conditions. Antioxidant enzyme activities and levels of non-enzymatic compounds were several folds higher in plants administered taurine under Cr and drought conditions. Further, taurine regulated osmotic adjustment under drought by enhancing the accumulation of organic osmolytes. In Cr-stressed plants, taurine reduced Cr uptake and improved nutrient acquisition. Taurine administration (100 and 200 mg L –1 ) notably circumvented the effects of individual and combined Cr and drought on plants. Taurine lessened the oxidative injury, improved secondary metabolites accumulation, bettered nutrient uptake, and strengthened the oxidative defense, enabling plants to cope with drought and Cr stress.