Comparing Hydraulics Between Two Grapevine Cultivars Reveals Differences in Stomatal Regulation Under Water Stress
Silvina Dayer1, Johannes D Scharwies1, Sunita A Ramesh1
1School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia.
Abstract:
Hydraulics of plants that have different strategies of stomatal regulation under water stress are relatively poorly understood. We explore how root and shoot hydraulics, stomatal conductance (g s), leaf and root aquaporin (AQP) expression, and abscisic acid (ABA) concentration in leaf xylem sap ([ABA]xylemsap) may be coordinated under mild water stress and exogenous ABA applications in two Vitis vinifera L. cultivars traditionally classified as near-isohydric (Grenache) and near-anisohydric (Syrah). Under water stress, Grenache exhibited stronger adjustments of plant and root hydraulic conductances and greater stomatal sensitivity to [ABA]xylemsap than Syrah resulting in greater conservation of soil moisture but not necessarily more isohydric behavior. Correlations between leaf (Ψleaf) and predawn (ΨPD) water potentials between cultivars suggested a "hydrodynamic" behavior rather than a particular iso-anisohydric classification. A significant decrease of Ψleaf in well-watered ABA-fed vines supported a role of ABA in the soil-leaf hydraulic pathway to regulate g s. Correlations between leaf and root AQPs expression levels under water deficit could explain the response of leaf (K leaf) and root (Lp r) hydraulic conductances in both cultivars. Additional studies under a wider range of soil water deficits are required to explore the possible differential regulation of g s and plant hydraulics in different cultivars and experimental conditions.
More Related Videos
07:08Identification of Novel Regulators of Plant Transpiration by Large-Scale Thermal Imaging Screening in Helianthus Annuus
Published on: January 30, 2020
15:30A Telemetric, Gravimetric Platform for Real-Time Physiological Phenotyping of Plant–Environment Interactions
Published on: August 5, 2020
Related Concept Videos
Adaptations that Reduce Water Loss
Regulation of Transpiration by Stomata
Responses to Drought and Flooding
Regulation of Water Output
Xylem and Transpiration-driven Transport of Resources
Responses to Salt Stress
