Negative allometry of leaf xylem conduit diameter and double-wall thickness: implications for implosion safety.

Autor: Matos IS; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA.; School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia., McDonough S; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Johnson BC; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Kalantar D; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Rohde J; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Sahu R; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Wang J; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Fontao A; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., To J; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Carlos S; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Garcia L; Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA., Boakye M; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA., Forbes H; University of California Botanical Garden, Berkeley, CA, 94720, USA., Blonder BW; Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, 94720, USA.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2024 Jun; Vol. 242 (6), pp. 2464-2478. Date of Electronic Publication: 2024 Apr 19.
DOI: 10.1111/nph.19771
Abstrakt: 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 scales T vs D to trade off safety, flow efficiency, mechanical support, and cost. We measured T and D in > 7000 conduits of 122 species to investigate how T vs D scaling 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 between T and D. That is, narrower conduits, which are usually subjected to more negative pressures, are proportionally safer than wider ones. Higher implosion safety (i.e. higher T/D ratios) 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.
(© 2024 The Authors New Phytologist © 2024 New Phytologist Foundation.)
Databáze: MEDLINE
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