Cerium alleviates drought-induced stress in Phaseolus vulgaris

Extreme drought events are expected to be one of the main challenges for tropical agriculture and, consequently, for global food security. For this reason, it is urgent to develop strategies to increase water use efficiency, as well as to increase crops' ability to cope with drought. Because rare earth elements (REEs) are known to alleviate damages in plants under abiotic stresses, we hypothesized that addition of Ce3+ to nutrient solution would promote the growth of common bean, especially under simulated drought stress. To test this hypothesis, we conducted an experiment evaluating the effect of six Ce3+ concentrations on the development and physiological traits of common bean grown in nutrient solution under normal condition and under induced drought stress, caused by the addition of polyethylene glycol 6000 to the nutrient solution. Our results show that Ce3+ alleviates water stress in common bean plants, increasing their survival rate and growth. In addition, Ce3+ application increases photosynthesis rate, chlorophyll content and water use efficiency under water stress. However, we observe no significant effect of Ce3+ on plants growing under normal condition. Therefore, Ce3+ seems to be a promising attenuator of drought stress for common bean. (C) 2020 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.