The impact of slow stomatal kinetics on photosynthesis and water use efficiency under fluctuating light

Abstract

Dynamic light conditions require continuous adjustments of stomatal aperture. The kinetics of stomatal conductance (gs) are hypothesized to be key to plant productivity and water use efficiency. Using step-changes in light intensity, we studied the diversity of light-induced gs kinetics in relation to stomatal anatomy in five banana genotypes (Musa spp.) and modelled the impact of both diffusional and biochemical limitations on photosynthesis (A). The dominant photosynthesis limiting factor was the diffusional limitation associated with gs kinetics. All genotypes exhibited a strong limitation of A by gs, indicating a priority for water saving. Moreover, significant genotypic differences in gs kinetics and gslimitations of A were observed. For two contrasting genotypes the impact of differential gs kinetics was further investigated under realistic diurnally fluctuating light conditions and at whole-plant level. Genotype-specific stomatal kinetics observed at the leaf level were corroborated at whole-plant level by transpiration dynamics, validating that genotype-specific responses are still maintained despite differences in gs control at different locations in the leaf and across leaves. However, under diurnally fluctuating light conditions the impact of gs speediness on A and intrinsic water use efficiency (iWUE) depended on time of day. During the afternoon there was a setback in kinetics: absolute gs and gs responses to light were damped, strongly limiting A and impacting diurnal iWUE. We conclude the impact of differential gs kinetics depended on target light intensity, magnitude of change, gs prior to the change in light intensity and particularly time of day.

Photosynthetic Paramaters of Two Indonesian Soybean Top Varieties

“…The effect of light intensity to the stomatal response occurs in two ways. The first is through the decrease of intercellular CO 2 concentration due to increase in photosynthesis (Eyland, van Wesemael, Lawson, & Carpentier, 2021), and the second is through direct activation of guard cells (Driesen, Van den Ende, De Proft, & Saeys, 2020;Elhaddad, Hunt, Sloan, & Gray, 2014;Ye et al, 2020). Unlike at normal condition, under Actinomycetes spp.…”

Photosynthetic Physiology Comparisons between No Tillage and Sod Culture of Citrus Farming in Different Seasons under Various Light Intensities

“…As the substrates of photosynthesis, CO 2 , and water are crucial to crop growth and yield, plants need to balance the CO 2 uptake for photosynthesis with water loss via transpiration for survival. Stomata control the exchange of gases between the leaf interior and the external atmosphere and improve WUE [9,32].…”

The potential of dynamic physiological traits in young tomato plants to predict field-yield performance

“…However, a clear understanding of the optimal stomatal conductance kinetics throughout the day and during the entire growing season as it reacts to dynamically changing environmental conditions is still a challenge. Several models have been proposed to understand the kinetics of stomatal conductance at leaf level [42][43][44] and quite a few at the whole plant level [45]. Although these models are good tools in predicting the kinetics of stomatal response to environment, still it is not easy to leverage the predicted or directly measured small dynamic responses on hourly, daily, and seasonal bases and translate it to final yield.…”