loading page

Mechanisms of xylem hydraulic recovery after drought in Eucalyptus saligna
  • +6
  • Alice Gauthey,
  • Jennifer Peters,
  • Rosana López,
  • Madeline Carins Murphy,
  • Celia M. Rodriguez-Dominguez,
  • David Tissue,
  • Belinda Medlyn,
  • Timothy Brodribb,
  • Brendan Choat
Alice Gauthey
Western Sydney University
Author Profile
Jennifer Peters
Western Sydney University Hawkesbury Institute for the Environment
Author Profile
Rosana López
Universidad Politécnica de Madrid
Author Profile
Madeline Carins Murphy
University of Tasmania
Author Profile
Celia M. Rodriguez-Dominguez
Instituto de Recursos Naturales y Agrobiología de Sevilla
Author Profile
David Tissue
Western Sydney University
Author Profile
Belinda Medlyn
Macquarie University
Author Profile
Timothy Brodribb
University of Tasmania
Author Profile
Brendan Choat
Western Sydney University
Author Profile

Abstract

The mechanisms by which woody plants recover xylem hydraulic capacity after drought stress are not well understood, particularly with regard to the role of embolism refilling. We evaluated the recovery of xylem hydraulic capacity in young Eucalyptus saligna plants exposed to cycles of drought stress and rewatering. Plants were exposed to moderate and severe drought stress treatments, with recovery monitored at time intervals from 24 hrs to 6 months after rewatering. The percentage loss of xylem vessels due to embolism (PLV) was quantified at each time point using micro-computed tomography with stem water potential (Ψx) and whole plant transpiration (Eplant) measured prior to scans. Plants exposed to severe drought stress suffered high levels of embolism (47.38 ± 10.97 % PLV) and almost complete canopy loss. No evidence of embolism refilling was observed at 24 hrs, one week, or three weeks after rewatering despite rapid recovery in Ψx. Recovery of hydraulic capacity was achieved over a 6-month period by growth of new xylem tissue, with canopy leaf area and Eplant recovering over the same period. These findings indicate that E. saligna recovers slowly from severe drought stress, with potential for embolism to persist in the xylem for many months after rainfall.

Peer review status:UNDER REVIEW

27 Apr 2021Submitted to Plant, Cell & Environment
27 Apr 2021Assigned to Editor
27 Apr 2021Submission Checks Completed
03 May 2021Reviewer(s) Assigned
31 May 2021Review(s) Completed, Editorial Evaluation Pending