Cargando…
Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf
Leaf hydraulic conductance (k (leaf)) is a central element in the regulation of leaf water balance but the properties of k (leaf) remain uncertain. Here, the evidence for the following two models for k (leaf) in well-hydrated plants is evaluated: (i) k (leaf) is constant or (ii) k (leaf) increases a...
Autores principales: | , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2015
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4339593/ https://www.ncbi.nlm.nih.gov/pubmed/25547915 http://dx.doi.org/10.1093/jxb/eru481 |
_version_ | 1782358889119875072 |
---|---|
author | Simonin, Kevin A. Burns, Emily Choat, Brendan Barbour, Margaret M. Dawson, Todd E. Franks, Peter J. |
author_facet | Simonin, Kevin A. Burns, Emily Choat, Brendan Barbour, Margaret M. Dawson, Todd E. Franks, Peter J. |
author_sort | Simonin, Kevin A. |
collection | PubMed |
description | Leaf hydraulic conductance (k (leaf)) is a central element in the regulation of leaf water balance but the properties of k (leaf) remain uncertain. Here, the evidence for the following two models for k (leaf) in well-hydrated plants is evaluated: (i) k (leaf) is constant or (ii) k (leaf) increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨ(stem–leaf)), stomatal conductance (g (s)), k (leaf), and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO(2) concentration were evaluated. Results show that for well-watered plants k (leaf) is positively dependent on E. Here, this property is termed the dynamic conductance, k (leaf(E)), which incorporates the inherent k (leaf) at zero E, which is distinguished as the static conductance, k (leaf(0)). Growth under different CO(2) concentrations maintained the same relationship between k (leaf) and E, resulting in similar k (leaf(0)), while operating along different regions of the curve owing to the influence of CO(2) on g (s). The positive relationship between k (leaf) and E minimized variation in ΔΨ(stem–leaf). This enables leaves to minimize variation in Ψ(leaf) and maximize g (s) and CO(2) assimilation rate over the diurnal course of evaporative demand. |
format | Online Article Text |
id | pubmed-4339593 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-43395932015-06-26 Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf Simonin, Kevin A. Burns, Emily Choat, Brendan Barbour, Margaret M. Dawson, Todd E. Franks, Peter J. J Exp Bot Research Paper Leaf hydraulic conductance (k (leaf)) is a central element in the regulation of leaf water balance but the properties of k (leaf) remain uncertain. Here, the evidence for the following two models for k (leaf) in well-hydrated plants is evaluated: (i) k (leaf) is constant or (ii) k (leaf) increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨ(stem–leaf)), stomatal conductance (g (s)), k (leaf), and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO(2) concentration were evaluated. Results show that for well-watered plants k (leaf) is positively dependent on E. Here, this property is termed the dynamic conductance, k (leaf(E)), which incorporates the inherent k (leaf) at zero E, which is distinguished as the static conductance, k (leaf(0)). Growth under different CO(2) concentrations maintained the same relationship between k (leaf) and E, resulting in similar k (leaf(0)), while operating along different regions of the curve owing to the influence of CO(2) on g (s). The positive relationship between k (leaf) and E minimized variation in ΔΨ(stem–leaf). This enables leaves to minimize variation in Ψ(leaf) and maximize g (s) and CO(2) assimilation rate over the diurnal course of evaporative demand. Oxford University Press 2015-03 2014-12-29 /pmc/articles/PMC4339593/ /pubmed/25547915 http://dx.doi.org/10.1093/jxb/eru481 Text en © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. http://creativecommons.org/licenses/by/3.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Paper Simonin, Kevin A. Burns, Emily Choat, Brendan Barbour, Margaret M. Dawson, Todd E. Franks, Peter J. Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf |
title | Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf |
title_full | Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf |
title_fullStr | Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf |
title_full_unstemmed | Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf |
title_short | Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf |
title_sort | increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf |
topic | Research Paper |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4339593/ https://www.ncbi.nlm.nih.gov/pubmed/25547915 http://dx.doi.org/10.1093/jxb/eru481 |
work_keys_str_mv | AT simoninkevina increasingleafhydraulicconductancewithtranspirationrateminimizesthewaterpotentialdrawdownfromstemtoleaf AT burnsemily increasingleafhydraulicconductancewithtranspirationrateminimizesthewaterpotentialdrawdownfromstemtoleaf AT choatbrendan increasingleafhydraulicconductancewithtranspirationrateminimizesthewaterpotentialdrawdownfromstemtoleaf AT barbourmargaretm increasingleafhydraulicconductancewithtranspirationrateminimizesthewaterpotentialdrawdownfromstemtoleaf AT dawsontodde increasingleafhydraulicconductancewithtranspirationrateminimizesthewaterpotentialdrawdownfromstemtoleaf AT frankspeterj increasingleafhydraulicconductancewithtranspirationrateminimizesthewaterpotentialdrawdownfromstemtoleaf |