Aquaporin regulation in roots controls plant hydraulic conductance, stomatal conductance, and leaf water potential in Pinus radiata under water stress.

Autor: Rodríguez-Gamir J; Departamento de Suelos y Riegos, Instituto Canario de Investigaciones Agrarias (ICIA), Ctra de El boquerón s/n. 38270. San Cristóbal de La Laguna, Tenerife, Canary Islands, Spain.; Forest Systems, Scion, PO Box 29237, Christchurch, 8440, New Zealand., Xue J; Forest Systems, Scion, PO Box 29237, Christchurch, 8440, New Zealand., Clearwater MJ; Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, New Zealand., Meason DF; Forest Systems, Scion, Private Bag 3020, Rotorua, 3046, New Zealand., Clinton PW; Forest Systems, Scion, PO Box 29237, Christchurch, 8440, New Zealand., Domec JC; Bordeaux Sciences Agro, UMR INRA ISPA 1391, Gradignan, France.; Nicholas School of the Environment, Duke University, Durham, North Carolina, USA.
Jazyk: angličtina
Zdroj: Plant, cell & environment [Plant Cell Environ] 2019 Feb; Vol. 42 (2), pp. 717-729. Date of Electronic Publication: 2018 Nov 19.
DOI: 10.1111/pce.13460
Abstrakt: Stomatal regulation is crucial for forest species performance and survival on drought-prone sites. We investigated the regulation of root and shoot hydraulics in three Pinus radiata clones exposed to drought stress and its coordination with stomatal conductance (g s ) and leaf water potential (Ψ leaf ). All clones experienced a substantial decrease in root-specific root hydraulic conductance (K root-r ) in response to the water stress, but leaf-specific shoot hydraulic conductance (K shoot-l ) did not change in any of the clones. The reduction in K root-r caused a decrease in leaf-specific whole-plant hydraulic conductance (K plant-l ). Among clones, the larger the decrease in K plant-l , the more stomata closed in response to drought. Rewatering resulted in a quick recovery of K root-r and g s . Our results demonstrated that the reduction in K plant-l , attributed to a down regulation of aquaporin activity in roots, was linked to the isohydric stomatal behaviour, resulting in a nearly constant Ψ leaf as water stress started. We concluded that higher K plant-l is associated with water stress resistance by sustaining a less negative Ψ leaf and delaying stomatal closure.
(© 2018 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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