Cargando…

Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture

When soil moisture is heterogeneous, sap flow from, and ABA status of, different parts of the root system impact on leaf xylem ABA concentration ([X-ABA](leaf)). The robustness of a model for predicting [X-ABA](leaf) was assessed. ‘Two root-one shoot’ grafted sunflower (Helianthus annuus L.) plants...

Descripción completa

Detalles Bibliográficos
Autores principales: Dodd, Ian C., Egea, Gregorio, Davies, William J.
Formato: Texto
Lenguaje:English
Publicado: Oxford University Press 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2639021/
https://www.ncbi.nlm.nih.gov/pubmed/18940933
http://dx.doi.org/10.1093/jxb/ern246
_version_ 1782164437096988672
author Dodd, Ian C.
Egea, Gregorio
Davies, William J.
author_facet Dodd, Ian C.
Egea, Gregorio
Davies, William J.
author_sort Dodd, Ian C.
collection PubMed
description When soil moisture is heterogeneous, sap flow from, and ABA status of, different parts of the root system impact on leaf xylem ABA concentration ([X-ABA](leaf)). The robustness of a model for predicting [X-ABA](leaf) was assessed. ‘Two root-one shoot’ grafted sunflower (Helianthus annuus L.) plants received either deficit irrigation (DI, each root system received the same irrigation volumes) or partial rootzone drying (PRD, only one root system was watered and the other dried the soil). Irrespective of whether relative sap flow was assessed using sap flow sensors in vivo or by pressurization of de-topped roots, each root system contributed similarly to total sap flow during DI, while sap flow from roots in drying soil declined linearly with soil water potential (Ψ(soil)) during PRD. Although Ψ(soil) of the irrigated pot determined the threshold Ψ(soil) at which sap flow from roots in drying soil decreased, the slope of this decrease was independent of the wet pot Ψ(soil). Irrespective of whether sap was collected from the wet or dry root system of PRD plants, or a DI plant, root xylem ABA concentration increased as Ψ(soil) declined. The model, which weighted ABA contributions of each root system according to the sap flow from each, almost perfectly explained [X-ABA] immediately above the graft union. That the model overestimated measured [X-ABA](leaf) may result from changes in [X-ABA] along the transport pathway or an artefact of collecting xylem sap from detached leaves. The implications of declining sap flow through partially dry roots during PRD for the control of stomatal behaviour and irrigation scheduling are discussed.
format Text
id pubmed-2639021
institution National Center for Biotechnology Information
language English
publishDate 2008
publisher Oxford University Press
record_format MEDLINE/PubMed
spelling pubmed-26390212009-02-25 Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture Dodd, Ian C. Egea, Gregorio Davies, William J. J Exp Bot Research Papers When soil moisture is heterogeneous, sap flow from, and ABA status of, different parts of the root system impact on leaf xylem ABA concentration ([X-ABA](leaf)). The robustness of a model for predicting [X-ABA](leaf) was assessed. ‘Two root-one shoot’ grafted sunflower (Helianthus annuus L.) plants received either deficit irrigation (DI, each root system received the same irrigation volumes) or partial rootzone drying (PRD, only one root system was watered and the other dried the soil). Irrespective of whether relative sap flow was assessed using sap flow sensors in vivo or by pressurization of de-topped roots, each root system contributed similarly to total sap flow during DI, while sap flow from roots in drying soil declined linearly with soil water potential (Ψ(soil)) during PRD. Although Ψ(soil) of the irrigated pot determined the threshold Ψ(soil) at which sap flow from roots in drying soil decreased, the slope of this decrease was independent of the wet pot Ψ(soil). Irrespective of whether sap was collected from the wet or dry root system of PRD plants, or a DI plant, root xylem ABA concentration increased as Ψ(soil) declined. The model, which weighted ABA contributions of each root system according to the sap flow from each, almost perfectly explained [X-ABA] immediately above the graft union. That the model overestimated measured [X-ABA](leaf) may result from changes in [X-ABA] along the transport pathway or an artefact of collecting xylem sap from detached leaves. The implications of declining sap flow through partially dry roots during PRD for the control of stomatal behaviour and irrigation scheduling are discussed. Oxford University Press 2008-11 2008-10-21 /pmc/articles/PMC2639021/ /pubmed/18940933 http://dx.doi.org/10.1093/jxb/ern246 Text en © 2008 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper is available online free of all access charges (see http://jxb.oxfordjournals.org/open_access.html for further details)
spellingShingle Research Papers
Dodd, Ian C.
Egea, Gregorio
Davies, William J.
Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture
title Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture
title_full Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture
title_fullStr Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture
title_full_unstemmed Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture
title_short Accounting for sap flow from different parts of the root system improves the prediction of xylem ABA concentration in plants grown with heterogeneous soil moisture
title_sort accounting for sap flow from different parts of the root system improves the prediction of xylem aba concentration in plants grown with heterogeneous soil moisture
topic Research Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2639021/
https://www.ncbi.nlm.nih.gov/pubmed/18940933
http://dx.doi.org/10.1093/jxb/ern246
work_keys_str_mv AT doddianc accountingforsapflowfromdifferentpartsoftherootsystemimprovesthepredictionofxylemabaconcentrationinplantsgrownwithheterogeneoussoilmoisture
AT egeagregorio accountingforsapflowfromdifferentpartsoftherootsystemimprovesthepredictionofxylemabaconcentrationinplantsgrownwithheterogeneoussoilmoisture
AT davieswilliamj accountingforsapflowfromdifferentpartsoftherootsystemimprovesthepredictionofxylemabaconcentrationinplantsgrownwithheterogeneoussoilmoisture