How do plants cope with drought and metal co-exposure?—An unexplored field to unravel

Abstract

Plants, as sessile organisms, are continuously exposed to one or multiple biotic and abiotic stresses, including the combination of drought and metals, which can severely reduce plant growth. Since this combination has recently emerged as an area of research, this review gathered, for the first time, the available data on the joint impacts of drought and metals in several aspects of plant physiology. Throughout this review, the effects of this stress combination on key plant physiological processes such as photosynthesis, nitrogen metabolism, and redox status were discussed, highlighting the synergistic and antagonistic impacts of one stress on the other. The hormetic effects of metals over drought were also discussed. Furthermore, focus was also placed on how these two stressors impact DNA and hormonal balance. Finally, a mechanistic overview, suggesting new lines of research to address gaps in the understanding of the effects of drought and metals on plant physiology, was drawn. This knowledge is pivotal for the development of effective strategies to mitigate the impact of this combined stress, offering a pathway towards increased plant resilience in an ever-changing environment.