Physiological trait networks enhance understanding of crop growth and water use in contrasting environments

• Published in: Plant, cell and environment cell and environment, 2022-09, Vol.45 (9), p.2554-2572
• Main Authors: Gleason, Sean M., Barnard, Dave M., Green, Timothy R., Mackay, Scott, Wang, Diane R., Ainsworth, Elizabeth A., Altenhofen, Jon, Brodribb, Timothy J., Cochard, Hervé, Comas, Louise H., Cooper, Mark, Creek, Danielle, DeJonge, Kendall C., Delzon, Sylvain, Fritschi, Felix B., Hammer, Graeme, Hunter, Cameron, Lombardozzi, Danica, Messina, Carlos D., Ocheltree, Troy, Stevens, Bo Maxwell, Stewart, Jared J., Vadez, Vincent, Wenz, Joshua, Wright, Ian J., Yemoto, Kevin, Zhang, Huihui
• Format: Article
• Language: English
• Subjects: Agricultural production; breeding; Conductance; Crop growth; crop improvement; Crop yield; Embolism; Environmental Sciences; Grain; hydraulic traits; Leaf area; Leaf area index; Leaves; maize; Net Primary Productivity; Networks; Performance prediction; photosynthesis; Physiology; plant growth; Precipitation; process simulation; Roots; Simulation; Soil characteristics; Soils; Stomata; Stomatal conductance; Water potential; Water use; Xylem
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/pce.14382

Plant function arises from a complex network of structural and physiological traits. Explicit representation of these traits, as well as their connections with other biophysical processes, is required to advance our understanding of plant‐soil‐climate interactions. We used the Terrestrial Regional Ecosystem Exchange Simulator (TREES) to evaluate physiological trait networks in maize. Net primary productivity (NPP) and grain yield were simulated across five contrasting climate scenarios. Simulations achieving high NPP and grain yield in high precipitation environments featured trait networks conferring high water use strategies: deep roots, high stomatal conductance at low water potential (“risky” stomatal regulation), high xylem hydraulic conductivity and high maximal leaf area index. In contrast, high NPP and grain yield was achieved in dry environments with low late‐season precipitation via water conserving trait networks: deep roots, high embolism resistance and low stomatal conductance at low leaf water potential (“conservative” stomatal regulation). We suggest that our approach, which allows for the simultaneous evaluation of physiological traits, soil characteristics and their interactions (i.e., networks), has potential to improve our understanding of crop performance in different environments. In contrast, evaluating single traits in isolation of other coordinated traits does not appear to be an effective strategy for predicting plant performance. Our process‐based model uncovered two beneficial but contrasting trait networks for maize which can be understood by their integrated effect on water use/conservation. Modification of multiple, physiologically aligned, traits were required to bring about meaningful improvements in NPP and yield.