Journal
NEW PHYTOLOGIST
Volume 216, Issue 3, Pages 720-727Publisher
WILEY
DOI: 10.1111/nph.14787
Keywords
acoustic emissions; drought stress; embolism repair; internal CO2 transport; Populus nigra; surfactants; vulnerability curve; woody tissue (stem) photosynthesis
Categories
Funding
- Research Foundation Flanders (FWO) [G.0319.13N, G.0941.15N]
- Universidad Politecnica de Madrid
- FWO [PEGASUS]2Marie Sklodowska-Curie [665501]
Ask authors/readers for more resources
Reassimilation of internal CO2 via woody tissue photosynthesis has a substantial effect on tree carbon income and wood production. However, little is known about its role in xylem vulnerability to cavitation and its implications in drought-driven tree mortality. Young trees of Populus nigra were subjected to light exclusion at the branch and stem levels. After 40 d, measurements of xylem water potential, diameter variation and acoustic emission (AE) were performed in detached branches to obtain acoustic vulnerability curves to cavitation following bench-top dehydration. Acoustic vulnerability curves and derived AE(50) values (i.e. water potential at which 50% of cavitation-related acoustic emissions occur) differed significantly between light-excluded and control branches (AE(50,light-excluded) = -1.00 +/- 0.13 MPa; AE(50,control) = -1.45 +/- 0.09 MPa; P = 0.007) denoting higher vulnerability to cavitation in light-excluded trees. Woody tissue photosynthesis represents an alternative and immediate source of nonstructural carbohydrates (NSC) that confers lower xylem vulnerability to cavitation via sugar-mediated mechanisms. Embolism repair and xylem structural changes could not explain this observation as the amount of cumulative AE and basic wood density did not differ between treatments. We suggest that woody tissue assimilates might play a role in the synthesis of xylem surfactants for nanobubble stabilization under tension.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available