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Is xylem of angiosperm leaves less resistant to embolism than branches? Insights from microCT, hydraulics, and anatomy.
Klepsch, Matthias; Zhang, Ya; Kotowska, Martyna M; Lamarque, Laurent J; Nolf, Markus; Schuldt, Bernhard; Torres-Ruiz, José M; Qin, De-Wen; Choat, Brendan; Delzon, Sylvain; Scoffoni, Christine; Cao, Kun-Fang; Jansen, Steven.
Afiliação
  • Klepsch M; Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, Ulm University, Ulm, Germany.
  • Zhang Y; Institute of Systematic Botany and Ecology, Albert-Einstein-Allee 11, Ulm University, Ulm, Germany.
  • Kotowska MM; Department of Biological Sciences Faculty of Science, Macquarie University, NSW, Australia.
  • Lamarque LJ; Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle, Göttingen, Germany.
  • Nolf M; BIOGECO, INRA, University of Bordeaux, Pessac, France.
  • Schuldt B; EGFV, INRA, University of Bordeaux, Villenave d'Ornon, France.
  • Torres-Ruiz JM; Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, New South Wales, Australia.
  • Qin DW; Plant Ecology, Albrecht von Haller Institute for Plant Sciences, University of Göttingen, Untere Karspüle, Göttingen, Germany.
  • Choat B; BIOGECO, INRA, University of Bordeaux, Pessac, France.
  • Delzon S; Université Clermont-Auvergne, INRA, PIAF, Clermont-Ferrand, France.
  • Scoffoni C; Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Daxuedonglu, Nanning, Guangxi, PR China.
  • Cao KF; Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, New South Wales, Australia.
  • Jansen S; BIOGECO, INRA, University of Bordeaux, Pessac, France.
J Exp Bot ; 69(22): 5611-5623, 2018 11 26.
Article em En | MEDLINE | ID: mdl-30184113
ABSTRACT
According to the hydraulic vulnerability segmentation hypothesis, leaves are more vulnerable to decline of hydraulic conductivity than branches, but whether stem xylem is more embolism resistant than leaves remains unclear. Drought-induced embolism resistance of leaf xylem was investigated based on X-ray microcomputed tomography (microCT) for Betula pendula, Laurus nobilis, and Liriodendron tulipifera, excluding outside-xylem, and compared with hydraulic vulnerability curves for branch xylem. Moreover, bordered pit characters related to embolism resistance were investigated for both organs. Theoretical P50 values (i.e. the xylem pressure corresponding to 50% loss of hydraulic conductance) of leaves were generally within the same range as hydraulic P50 values of branches. P50 values of leaves were similar to branches for L. tulipifera (-2.01 versus -2.10 MPa, respectively), more negative for B. pendula (-2.87 versus -1.80 MPa), and less negative for L. nobilis (-6.4 versus -9.2 MPa). Despite more narrow conduits in leaves than branches, mean interconduit pit membrane thickness was similar in both organs, but significantly higher in leaves of B. pendula than in branches. This case study indicates that xylem shows a largely similar embolism resistance across leaves and branches, although differences both within and across organs may occur, suggesting interspecific variation with regard to the hydraulic vulnerability segmentation hypothesis.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Árvores / Betula / Laurus / Liriodendron / Xilema / Secas Idioma: En Revista: J Exp Bot Assunto da revista: BOTANICA Ano de publicação: 2018 Tipo de documento: Article País de afiliação: Alemanha

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Árvores / Betula / Laurus / Liriodendron / Xilema / Secas Idioma: En Revista: J Exp Bot Assunto da revista: BOTANICA Ano de publicação: 2018 Tipo de documento: Article País de afiliação: Alemanha