Role of hydraulic traits in stomatal regulation of transpiration under different vapour pressure deficits across five Mediterranean tree crops

The differential stomatal regulation of transpiration among plant species in response to water deficit is not fully understood, although several hydraulic traits have been reported to influence it. This knowledge gap is partly due to a lack of direct and concomitant experimental data on transpiratio...

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Bibliographic Details
Authors: Hernández Santana, Virginia, Rodríguez Domínguez, Celia M., Sebastián Azcona, Jaime, Pérez Romero, Luis Felipe, Díaz Espejo, Antonio
Format: article
Publication Date:2023
Country:España
Institution:Universidad de Huelva (UHU)
Repository:Arias Montano. Repositorio Institucional de la Universidad de Huelva
Language:English
OAI Identifier:oai:ariasmontano.uhu.es:10272/23307
Online Access:https://hdl.handle.net/10272/23307
Access Level:Open access
Keyword:Almond
Grapefruit
Huber value
Lemon
Olive
Orange
Plant hydraulic conductance
Sap flux density
Stomatal conductance
Vapour pressure deficit
2417 Biología Vegetal (Botánica)
Description
Summary:The differential stomatal regulation of transpiration among plant species in response to water deficit is not fully understood, although several hydraulic traits have been reported to influence it. This knowledge gap is partly due to a lack of direct and concomitant experimental data on transpiration, stomatal conductance, and hydraulic traits. We measured sap flux density (Js), stomatal conductance (gs), and different hydraulic traits in five crop species. Our aim was to contribute to establishing the causal relationship between water consumption and its regulation using a hydraulic trait-based approach. The results showed that the species-specific regulation of Js by gs was overall coordinated with the functional hydraulic traits analysed. Particularly relevant was the negative and significant relationship found between the Huber value (Hv) and its functional analogue ratio between maximum Js and gs (Jsmax/gsmax) which can be understood as a compensation to maintain the hydraulic supply to the leaves. The Hv was also significantly related to the slope of the relationship between gs and Js response to vapour pressure deficit and explained most of its variability, adding up to evidence recognizing Hv as a major trait in plant water relations. Thus, a hydraulic basis for regulation of tree water use should be considered.