title: Noninvasive Measurement of Vulnerability to Drought-Induced Embolism by X-Ray Microtomography.
abstract: Hydraulic failure induced by xylem embolism is one of the primary mechanisms of plant dieback during drought. However, many of the methods used to evaluate the vulnerability of different species to drought-induced embolism are indirect and invasive, increasing the possibility that measurement artifacts may occur. Here, we utilize x-ray computed microtomography (microCT) to directly visualize embolism formation in the xylem of living, intact plants with contrasting wood anatomy (Quercus robur, Populus tremula × Populus alba, and Pinus pinaster). These observations were compared with widely used centrifuge techniques that require destructive sampling. MicroCT imaging provided detailed spatial information regarding the dimensions and functional status of xylem conduits during dehydration. Vulnerability curves based on microCT observations of intact plants closely matched curves based on the centrifuge technique for species with short vessels (P. tremula × P. alba) or tracheids (P. pinaster). For ring porous Q. robur, the centrifuge technique significantly overestimated vulnerability to embolism, indicating that caution should be used when applying this technique to species with long vessels. These findings confirm that microCT can be used to assess the vulnerability to embolism on intact plants by direct visualization.
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia (B.C.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, F-63100 Clermont-Ferrand, France (E.B., H.C.);Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (E.B., H.C.);Institut National de la Recherche Agronomique, University of Bordeaux, Unité Mixte de Recherche BIOGECO, F-33450 Talence, France (R.B., S.D.); andInstitute for Systematic Botany and Ecology, Ulm University, 89081 Ulm, Germany (S.J.) b.choat@westernsydney.edu.au.
authors.forename: Brendan
authors.initials: B
authors.lastname: Choat
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia (B.C.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, F-63100 Clermont-Ferrand, France (E.B., H.C.);Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (E.B., H.C.);Institut National de la Recherche Agronomique, University of Bordeaux, Unité Mixte de Recherche BIOGECO, F-33450 Talence, France (R.B., S.D.); andInstitute for Systematic Botany and Ecology, Ulm University, 89081 Ulm, Germany (S.J.).
authors.forename: Eric
authors.identifier: http://orcid.org/0000-0003-2282-7554
authors.initials: E
authors.lastname: Badel
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia (B.C.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, F-63100 Clermont-Ferrand, France (E.B., H.C.);Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (E.B., H.C.);Institut National de la Recherche Agronomique, University of Bordeaux, Unité Mixte de Recherche BIOGECO, F-33450 Talence, France (R.B., S.D.); andInstitute for Systematic Botany and Ecology, Ulm University, 89081 Ulm, Germany (S.J.).
authors.forename: Regis
authors.identifier: http://orcid.org/0000-0001-8289-5757
authors.initials: R
authors.lastname: Burlett
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia (B.C.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, F-63100 Clermont-Ferrand, France (E.B., H.C.);Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (E.B., H.C.);Institut National de la Recherche Agronomique, University of Bordeaux, Unité Mixte de Recherche BIOGECO, F-33450 Talence, France (R.B., S.D.); andInstitute for Systematic Botany and Ecology, Ulm University, 89081 Ulm, Germany (S.J.).
authors.forename: Sylvain
authors.identifier: http://orcid.org/0000-0003-3442-1711
authors.initials: S
authors.lastname: Delzon
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia (B.C.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, F-63100 Clermont-Ferrand, France (E.B., H.C.);Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (E.B., H.C.);Institut National de la Recherche Agronomique, University of Bordeaux, Unité Mixte de Recherche BIOGECO, F-33450 Talence, France (R.B., S.D.); andInstitute for Systematic Botany and Ecology, Ulm University, 89081 Ulm, Germany (S.J.).
authors.forename: Herve
authors.initials: H
authors.lastname: Cochard
authors.affiliation: Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia (B.C.);Institut National de la Recherche Agronomique, Unité Mixte de Recherche 547 PIAF, F-63100 Clermont-Ferrand, France (E.B., H.C.);Université Blaise-Pascal, Unité Mixte de Recherche 547 PIAF, 63000 Clermont-Ferrand, France (E.B., H.C.);Institut National de la Recherche Agronomique, University of Bordeaux, Unité Mixte de Recherche BIOGECO, F-33450 Talence, France (R.B., S.D.); andInstitute for Systematic Botany and Ecology, Ulm University, 89081 Ulm, Germany (S.J.).
authors.forename: Steven
authors.initials: S
authors.lastname: Jansen
mesh_terms: D055864:Droughts; D021621:Imaging, Three-Dimensional; D028223:Pinus / Q000033:anatomy & histology / Q000502:physiology; D018547:Plant Stems / Q000502:physiology; D032107:Populus / Q000033:anatomy & histology / Q000502:physiology; D029963:Quercus / Q000033:anatomy & histology / Q000502:physiology; D055114:X-Ray Microtomography / Q000379:methods*; D052584:Xylem / Q000033:anatomy & histology / Q000502:physiology*