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Title: Negative allometry of leaf xylem conduit diameter and double‐wall thickness: implications for implosion safety
Summary Xylem conduits have lignified walls to resist crushing pressures. The thicker the double‐wall (T) relative to its diameter (D), the greater the implosion safety. Having safer conduits may incur higher costs and reduced flow, while having less resistant xylem may lead to catastrophic collapse under drought. Although recent studies have shown that conduit implosion commonly occurs in leaves, little is known about how leaf xylem scalesTvsDto trade off safety, flow efficiency, mechanical support, and cost.We measuredTandDin > 7000 conduits of 122 species to investigate howTvsDscaling varies across clades, habitats, growth forms, leaf, and vein sizes.As conduits become wider, their double‐cell walls become proportionally thinner, resulting in a negative allometry betweenTandD. That is, narrower conduits, which are usually subjected to more negative pressures, are proportionally safer than wider ones. Higher implosion safety (i.e. higherT/Dratios) was found in asterids, arid habitats, shrubs, small leaves, and minor veins.Despite the strong allometry, implosion safety does not clearly trade off with other measured leaf functions, suggesting that implosion safety at whole‐leaf level cannot be easily predicted solely by individual conduits' anatomy.  more » « less
Award ID(s):
2025282
PAR ID:
10565418
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
New Phytologist
Date Published:
Journal Name:
New Phytologist
Volume:
242
Issue:
6
ISSN:
0028-646X
Page Range / eLocation ID:
2464 to 2478
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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