Abscisic acid as a gateway for the crops of tomorrow

Abstract Plant cultivation and improvement has enabled large scale high-productivity agriculture that supports increasing populations, however, climate change will likely affect its long-term productivity. To safeguard against this and to provide solutions to the yield losses caused by abiotic stress, many efforts are under way to enhance crop yield and resilience. One facet of these efforts focuses on the plant hormone abscisic acid (ABA), which controls a variety of plant developmental processes, abiotic, and biotic stress responses. ABA's role in stomatal conductance, and thus plant water use, makes the ABA signaling pathway an attractive target for both genetic and chemical manipulation of crop water use and stress tolerance. Here we review recent advances in our understanding of ABA mediated responses and adaptation to abiotic stress, with a focus on agriculture and recent successful examples of harnessing it to develop crops with improved yield and enhanced stress tolerance. In particular, we highlight the development of transgenic wheat with improved water productivity achieved by ABA receptor overexpression, engineered ABA receptors for orthogonal activation of signaling, new ABA receptor agonists for tuning water use dynamically, and the use of ABA itself to increase yield during modest water stress in field conditions.