Elevated [CO₂] alleviates the impacts of water deficit on xylem anatomy and hydraulic properties of maize stems

Abstract

Plants can modify xylem anatomy and hydraulic properties to adjust to water status. Elevated [CO2] can increase plant water potential via reduced stomatal conductance and water loss. This raises the question of whether elevated [CO2], which thus improves plant water status, will reduce the impacts of soil water deficit on xylem anatomy and hydraulic properties of plants. To analyse the impacts of water and [CO2] on maize stem xylem anatomy and hydraulic properties, we exposed potted maize plants to varying [CO2] levels (400, 700, 900, and 1,200 ppm) and water levels (full irrigation and deficit irrigation). Results showed that at current [CO2], vessel diameter, vessel roundness, stem cross‐section area, specific hydraulic conductivity, and vulnerability to embolism decreased under deficit irrigation; yet, these impacts of deficit irrigation were reduced at elevated [CO2]. Across all treatments, midday stem water potential was tightly correlated with xylem traits and displayed similar responses. A distinct trade‐off between efficiency and safety in stem xylem water transportation in response to water deficit was observed at current [CO2] but not observed at elevated [CO2]. The results of this study enhance our knowledge of plant hydraulic acclimation under future climate environments and provide insights into trade‐offs in xylem structure and function.

Interactive Effect of Elevated CO2 and Moisture Stress on Anatomical Configuration in Brassica Species

“…The solid pith was consisted of parenchyma cells. Vessel roundness with diameter, stem cross-sectional of area stem, specific hydraulic conductivity, and embolism decreased under moisture stress condition but these impacts of stress were reduced at higher level of atmospheric CO2 [16].…”

“…Size and number of constituents of secondary xylem also affected by elevated CO2. In terrestrial vegetation long-distance, less resistance water transport path, xylem allows quick and extensive movement of water from roots to foliage and is required to maintain gas exchange in leaves under dry environment [16]. Therfore elevated CO2 may have positive response to alleviation of tress by modifying or altering the xylem physiology.…”

Elevated CO₂ and Water Stress in Combination in Plants: Vanguards for Adaptation to Changing Climate

“…A contrasting response was seen in the two grasses to elevated CO 2 and water stress, the difference in the species response was due to the stomatal characteristics as evident by the changes in transpiration rate and osmotic adjustment. Water status adjustment by modification of xylem anatomy and hyrdolyic properties is a mechanism found in many plants, its relationship with the observed effect of elevated CO 2 to increase plant water potential via reduced stomatal conductance and water loss was studied by Liu et al (2020). One the known adaptation to water stress by plants is to maintain high water potential and turgor pressure under water deficient conditions.…”

Structural and functional contributions of conducting tissues to genotypic and environmental variations of tomato fruit mass

“…8). Several studies showed that WD decreased the diameter of xylem vessels, in tomato pedicel (Rancic et al, 2008), in grape (Lovisolo and Schubert, 1998) and in maize (Abdel-Rahim et al, 1998 ;Liu et al, 2019). On poplar tree, Arend and Fromm (2007) showed that WD provoked a decrease in vessel size, but also an increase in the number of newly formed vessel cells.…”