Tip-to-base xylem conduit widening as an adaptation causes, consequences, and empirical priorities

Tip-to-base xylem conduit widening as an adaptation : causes, consequences, and empirical priorities

© 2020 The Authors New Phytologist © 2020 New Phytologist Foundation.

Bibliographische Detailangaben
Veröffentlicht in:The New phytologist. - 1979. - 229(2021), 4 vom: 15. Feb., Seite 1877-1893
1. Verfasser: Olson, Mark E (VerfasserIn)
Weitere Verfasser: Anfodillo, Tommaso, Gleason, Sean M, McCulloh, Katherine A
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2021
Zugriff auf das übergeordnete Werk:The New phytologist
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Review adaptation allometry conduit taper developmental constraint hydraulic architecture plant hydraulics mehr... tracheids vessels Water 059QF0KO0R
Beschreibung
Zusammenfassung:© 2020 The Authors New Phytologist © 2020 New Phytologist Foundation.
In the stems of terrestrial vascular plants studied to date, the diameter of xylem water-conducting conduits D widens predictably with distance from the stem tip L approximating D ∝ Lb , with b ≈ 0.2. Because conduit diameter is central for conductance, it is essential to understand the cause of this remarkably pervasive pattern. We give reason to suspect that tip-to-base conduit widening is an adaptation, favored by natural selection because widening helps minimize the increase in hydraulic resistance that would otherwise occur as an individual stem grows longer and conductive path length increases. Evidence consistent with adaptation includes optimality models that predict the 0.2 exponent. The fact that this prediction can be made with a simple model of a single capillary, omitting much biological detail, itself makes numerous important predictions, e.g. that pit resistance must scale isometrically with conduit resistance. The idea that tip-to-base conduit widening has a nonadaptive cause, with temperature, drought, or turgor limiting the conduit diameters that plants are able to produce, is less consistent with the data than an adaptive explanation. We identify empirical priorities for testing the cause of tip-to-base conduit widening and underscore the need to study plant hydraulic systems leaf to root as integrated wholes
Beschreibung:Date Completed 14.05.2021
Date Revised 14.05.2021
published: Print-Electronic
Citation Status MEDLINE
ISSN:1469-8137
DOI:10.1111/nph.16961