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Hydraulic efficiency and safety of vascular and non-vascular components in Pinus pinaster leaves

hal.structure.identifierLaboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier [PIAF]
dc.contributor.authorCHARRA-VASKOU, Katline
hal.structure.identifierLaboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier [PIAF]
dc.contributor.authorBADEL, Eric
hal.structure.identifierBiodiversité, Gènes & Communautés [BioGeCo]
dc.contributor.authorBURLETT, Régis
hal.structure.identifierLaboratoire de Physique et Physiologie Intégratives de l'Arbre Fruitier et Forestier [PIAF]
dc.contributor.authorCOCHARD, Hervé
hal.structure.identifierBiodiversité, Gènes & Communautés [BioGeCo]
dc.contributor.authorDELZON, Sylvain
hal.structure.identifierDepartment of Botany
dc.contributor.authorMAYR, Stefan
dc.date.issued2012
dc.identifier.issn0829-318X
dc.description.abstractEnLeaves, the distal section of the soil-plant-atmosphere continuum, exhibit the lowest water potentials in a plant. In contrast to angiosperm leaves, knowledge of the hydraulic architecture of conifer needles is scant. We investigated the hydraulic efficiency and safety of Pinus pinaster needles, comparing different techniques. The xylem hydraulic conductivity (k(s)) and embolism vulnerability (P-50) of both needle and stem were measured using the cavitron technique. The conductance and vulnerability of whole needles were measured via rehydration kinetics, and Cryo-SEM and 3D X-ray microtomographic observations were used as reference tools to validate physical measurements. The needle xylem of P. pinaster had lower hydraulic efficiency (k(s) = 2.0 x 10(-4) m(2) MPa-1 s(-1)) and safety (P-50 = - 1.5 MPa) than stem xylem (k(s) = 7.7 x 10(-4) m(2) MPa-1 s(-1); P-50 = - 3.6 to - 3.2 MPa). P-50 of whole needles (both extra-vascular and vascular pathways) was - 0.5 MPa, suggesting that non-vascular tissues were more vulnerable than the xylem. During dehydration to - 3.5 MPa, collapse and embolism in xylem tracheids, and gap formation in surrounding tissues were observed. However, a discrepancy in hydraulic and acoustic results appeared compared with visualizations, arguing for greater caution with these techniques when applied to needles. Our results indicate that the most distal parts of the water transport pathway are limiting for hydraulics of P. pinaster. Needle tissues exhibit a low hydraulic efficiency and low hydraulic safety, but may also act to buffer short-term water deficits, thus preventing xylem embolism.
dc.language.isoen
dc.publisherOxford University Press (OUP)
dc.subject.encavitation
dc.subject.encollapse
dc.subject.enconductivity
dc.subject.enconifer
dc.subject.enextra-vascular pathway
dc.subject.enmicrotomography
dc.subject.enneedle
dc.subject.envulnerability
dc.subject.enxylem
dc.subject.en3D visualization
dc.title.enHydraulic efficiency and safety of vascular and non-vascular components in Pinus pinaster leaves
dc.typeArticle de revue
dc.identifier.doi10.1093/treephys/tps071
dc.subject.halSciences du Vivant [q-bio]/Sciences agricoles
bordeaux.journalTree Physiology
bordeaux.page1161-1170
bordeaux.volume32
bordeaux.issue9
bordeaux.peerReviewedoui
hal.identifierhal-00964504
hal.version1
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00964504v1
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