Nocturnal foliar water uptake: an unexplored process in crops?

Plant water uptake is commonly rationalized as a daytime, root-driven process, mediated by stomatal responses to minimize water loss, optimize photosynthesis, and promote growth. This has led to a certain experimental bias in favor of studying daytime mechanisms and their role in survival under climate change (Gaston, 2019). However, critical, physiological processes also occur nocturnally and respond to changing climates. Despite advances into hydraulics, nocturnal foliar mechanisms facilitating crop survival under rising nighttime temperatures and water scarcity remain understudied. Here we highlight sources of nocturnal foliar water and discuss the leaf-level processes which could underpin crop resilience to warmer nights (Caird et al., 2007; Schoppach et al., 2014).