Dopamine-induced abiotic stress tolerance in horticultural plants

Dopamine is a naturally occurring amine in plants and animals, having a strong antioxidative capacity. Different abiotic stressors, such as drought, salinity, and nutrient deficiency induce endogenous dopamine biosynthesis, while exogenous dopamine application confers tolerance to abiotic stress. Plants benefit from exogenous dopamine to promote photosynthetic pigment concentrations, stomatal conductance, CO2 assimilation, and maximal photochemical efficiency, leading to improved growth and biomass accumulation under stressful conditions. Crucially, dopamine can alleviate oxidative stress caused by abiotic stressors by strengthening the antioxidant defense that functions in the efficient removal of reactive oxygen species. Dopamine assists plants in essential nutrient acquisition under deficit nutrient supply, possibly by regulating various ion transporters. Moreover, a role for ethylene signaling has been proposed for dopamine-induced nitrogen (N) assimilation and utilization under low N stress. Dopamine seems to favorably activate xenobiotic detoxification pathways, leading to improved degradation of organic pollutants. In this review, we discussed the role of dopamine in plant tolerance to abiotic stressors such as drought, salt stress, chilling, nutrient deficiency, nitrate excess and organic pollutant stress based on the available literature on horticultural plants. Our analysis suggests that the beneficial effects of dopamine on abiotic stress tolerance in plants point to the possibility of using dopamine to increase the sustainability of horticultural production in the era of climate change.