An inconvenient truth about xylem resistance to embolism in the model species for refilling Laurus nobilis L. - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Access content directly
Journal Articles Annals of Forest Science Year : 2018

An inconvenient truth about xylem resistance to embolism in the model species for refilling Laurus nobilis L.

Eric Badel
Timothy J. Brodribb
  • Function : Author
Régis Burlett
Brendan Choat
  • Function : Author
Hervé Cochard
Steven Jansen
Andrew King
  • Function : Author
  • PersonId : 864624
Nicolas Lenoir
  • Function : Author
Kathy Steppe
  • Function : Author
Jan van den Bulcke
  • Function : Author
Ya Zhang
  • Function : Author

Abstract

AbstractKey messageDirect, non-invasive X-ray microtomography and optical technique observations applied in stems and leaves of intact seedlings revealed that laurel is highly resistant to drought-induced xylem embolism. Contrary to what has been brought forward, daily cycles of embolism formation and refilling are unlikely to occur in this species and to explain how it copes with drought.ContextThere has been considerable controversy regarding xylem embolism resistance for long-vesselled angiosperm species and particularly for the model species for refilling (Laurus nobilis L.).AimsThe purpose of this study was to resolve the hydraulic properties of this species by documenting vulnerability curves of different organs in intact plants.MethodsHere, we applied a direct, non-invasive method to visualize xylem embolism in stems and leaves of intact laurel seedlings up to 2-m tall using X-ray microtomography (microCT) observations and the optical vulnerability technique. These approaches were coupled with complementary centrifugation measurements performed on 1-m long branches sampled from adult trees and compared with additional microCT analyses carried out on 80-cm cut branches.ResultsDirect observations of embolism spread during desiccation of intact laurels revealed that 50% loss of xylem conductivity (Ψ50) was reached at − 7.9 ± 0.5 and − 8.4 ± 0.3 MPa in stems and leaves, respectively, while the minimum xylem water potentials measured in the field were − 4.2 MPa during a moderate drought season. Those findings reveal that embolism formation is not routine in Laurus nobilis contrary to what has been previously reported. These Ψ50 values were close to those based on the flow-centrifuge technique (− 9.2 ± 0.2 MPa), but at odds with microCT observations of cut branches (− 4.0 ± 0.5 MPa).ConclusionIn summary, independent methods converge toward the same conclusion that laurel is highly resistant to xylem embolism regardless its development stage. Under typical growth conditions without extreme drought events, this species maintains positive hydraulic safety margin, while daily cycles of embolism formation and refilling are unlikely to occur in this species.
Fichier principal
Vignette du fichier
13595_2018_Article_768.pdf (3.5 Mo) Télécharger le fichier
Origin : Publication funded by an institution
Loading...

Dates and versions

hal-02288736 , version 1 (16-09-2019)

Identifiers

Cite

Laurent J. Lamarque, Déborah Corso, Jose Manuel Torres Ruiz, Eric Badel, Timothy J. Brodribb, et al.. An inconvenient truth about xylem resistance to embolism in the model species for refilling Laurus nobilis L.. Annals of Forest Science, 2018, 75 (3), pp.88. ⟨10.1007/s13595-018-0768-9⟩. ⟨hal-02288736⟩
50 View
34 Download

Altmetric

Share

Gmail Facebook X LinkedIn More