Crop physiology has emerged as an essential field in the face of mounting global challenges, such as climate change and environmental variability, which exert significant pressures on crop productivity. Fluctuating factors like drought, temperature extremes, and shifting light conditions directly influence crops’ carbon assimilation and transpiration processes, leading to instability in biomass accumulation and yield. Currently, the ability to optimize plant performance under these stresses is hindered by incomplete knowledge of how photosynthetic metabolism is regulated at the molecular, biochemical, and physiological levels, and how these processes interact with traits related to water use. Ongoing research debates the complexities of coordinating stomatal and mesophyll conductance with enzymatic activity and downstream metabolic flows, especially under dynamic environmental conditions. Although advances in genomics, transcriptomics, high-throughput phenotyping, and genome editing have greatly expanded investigative potential, there remain substantial gaps in bridging mechanisms at the molecular scale with field-level crop productivity.

This Research Topic aims to elucidate the regulatory networks and integrative mechanisms underpinning photosynthetic efficiency and water-use efficiency (WUE) in crops exposed to environmental variability. The primary objectives include identifying molecular, physiological, and metabolic determinants that optimize carbon assimilation relative to water loss, clarifying the multi-scale coordination between regulatory components, and determining robust targets that will support yield stability in water-limited and energy-limited systems. With a strong focus on translational perspectives, this Research Topic encourages studies leveraging recent technological innovations to answer critical questions regarding how crops can sustain productivity under stress, which molecular players are key to performance, and how these findings can inform future breeding and engineering strategies.

This Research Topic invites contributions that offer novel insights into the regulation, optimization, and engineering of photosynthetic and water-use efficiency at multiple biological scales in agricultural crops. Manuscripts should be limited to research that integrates molecular, biochemical, physiological, or modeling approaches relevant to crop carbon assimilation, water use, and adaptive responses. We welcome articles addressing, but not limited to, the following themes:

• Mechanisms regulating photosynthetic carbon assimilation under environmental stresses such as drought, extreme heat, high light, and light fluctuations
• Multi-scale coordination between stomatal and mesophyll conductance, and its impact on water-use efficiency
• Influence of enzymatic regulation and post-translational modifications on photosynthetic metabolic flux
• Omics and systems biology approaches to uncover regulatory networks governing photosynthetic performance
• Dynamics of carbon-water relations under combined environmental stresses (e.g., high VPD, elevated temperature)
• Natural genetic variation in photosynthetic capacity and water-use efficiency across crop species
• High-throughput phenotyping and modeling methodologies for evaluating carbon assimilation and water-use efficiency
• Genome editing and metabolic engineering strategies to enhance carbon gain and yield stability in crops

We welcome the following article types: original research articles, reviews, perspectives, and methodological studies.

Are you interested in contributing a manuscript to this Research Topic?

Dynamic Regulation of Photosynthetic Metabolism and Water-Use Efficiency in Crops