Plasticity in stomatal behaviour across a gradient of water supply is consistent among field‐grown maize inbred lines with varying stomatal patterning

Abstract

Stomata regulate leaf CO2 assimilation (A) and water loss. The Ball–Berry and Medlyn models predict stomatal conductance (gs) with a slope parameter (m or g1) that reflects the sensitivity of gs to A, atmospheric CO2 and humidity, and is inversely related to water use efficiency (WUE). This study addressed knowledge gaps about what the values of m and g1 are in C4 crops under field conditions, as well as how they vary among genotypes and with drought stress. Four inbred maize genotypes were unexpectedly consistent in how m and g1 decreased as water supply decreased. This was despite genotypic variation in stomatal patterning, A and gs. m and g1 were strongly correlated with soil water content, moderately correlated with predawn leaf water potential (Ψpd), but not correlated with midday leaf water potential (Ψmd). This implied that m and g1 respond to long‐term water supply more than short‐term drought stress. The conserved nature of m and g1 across anatomically diverse genotypes and water supplies suggests there is flexibility in structure‐function relationships underpinning WUE. This evidence can guide the simulation of maize gs across a range of water supply in the primary maize growing region and inform efforts to improve WUE.

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

“…However, two important caveats need to to be considered. Firstly, roots, stomata, and photochemistry are known to be significantly plastic in field grown maize (Ding et al, 2022;Gleason et al, 2017b;Schneider et al, 2020). Although we do not address trait plasticity here, we should almost certainly expect attenuation of adverse intrinsic trait effects via a coordinated plastic response.…”

Variations of stomata development in tea plant (Camellia sinensis) leaves in different light and temperature environments and genetic backgrounds

“…The stomata movement responding to the environmental and hormonal cues plays a key role in controlling transpiration rate and water use efficiency, CO 2 uptake for photosynthesis, as well as nutrient uptake [ 1 , 9 , 10 ]. Besides the stomata movement as a major way for the plant to adapt to water conditions, leaf stomata density, size and aperture change in response to other environmental factors, suchas low and high temperature, light or shade conditions, as wellas genetic factors [ 11 , 12 ]. Plants usually modify their stomata development to adapt and survive the changing environmental stresses.…”