Functional xylem characteristics associated with drought‐induced embolism in angiosperms

New Phytologist, vol. 236, pp. 2019–2036

Abstract

Hydraulic failure resulting from drought-induced embolism in the xylem of plants is a key determinant of reduced productivity and mortality. Methods to assess this vulnerability are difficult to achieve at scale, leading to alternative metrics and correlations with more easily measured traits. These efforts have led to the longstanding and pervasive assumed mechanistic link between vessel diameter and vulnerability in angiosperms. However, there are at least two problems with this assumption that requires critical re-evaluation: (1) our current understanding of drought-induced embolism does not provide a mechanistic explanation why increased vessel width should lead to greater vulnerability, and (2) the most recent advancements in nanoscale embolism processes suggest that vessel diameter is not a direct driver. Here, we review data from physiological and comparative wood anatomy studies, highlighting the potential anatomical and physicochemical drivers of embolism formation and spread. We then put forward key knowledge gaps, emphasising what is known, unknown and speculation. A meaningful evaluation of the diameter-vulnerability link will require a better mechanistic understanding of the biophysical processes at the nanoscale level that determine embolism formation and spread, which will in turn lead to more accurate predictions of how water transport in plants is affected by drought.

Authors 6

1. Frederic Lens corresponding Aachen Institute of Biology Leiden Naturalis Biodiversity Center

   Leiden University · Naturalis Biodiversity Center

   Affiliation as printed

   Leiden University Institute of Biology Leiden, Plant Sciences Sylviusweg 72 2333 BE Leiden the Netherlands

   Naturalis Biodiversity Center PO Box 9517 2300 RA Leiden the Netherlands

   Leiden University, Institute of Biology Leiden, Plant Sciences, Sylviusweg 72, 2333 BE Leiden, the Netherlands

   Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, the Netherlands

2. Sean M. Gleason

   Agricultural Research Service · United States Department of Agriculture · Agricultural Research Service - Plains Area

   Affiliation as printed

   Water Management and Systems Research Unit United States Department of Agriculture, Agricultural Research Service Fort Collins CO 80526 USA

   Water Management and Systems Research Unit, United States Department of Agriculture, Agricultural Research Service, Fort Collins, CO, 80526 USA

3. Giovanni Bortolami Aachen Naturalis Biodiversity Center

   Naturalis Biodiversity Center

   Affiliation as printed

   Naturalis Biodiversity Center PO Box 9517 2300 RA Leiden the Netherlands

   Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, the Netherlands

4. Craig R. Brodersen

   Yale University

   Affiliation as printed

   School of the Environment Yale University New Haven CT 06511 USA

   School of the Environment, Yale University, New Haven, CT, 06511 USA

5. Sylvain Delzon

   Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement · Université de Bordeaux · UMR BIOdiversity, GEnes & Communities

   Affiliation as printed

   University of Bordeaux, INRAE, BIOGECO 33615 Pessac France

   University of Bordeaux, INRAE, BIOGECO, 33615 Pessac, France

6. Steven Jansen

   Universität Ulm

   Affiliation as printed

   Institute of Systematic Botany and Ecology Ulm University Albert‐Einstein‐Allee 11 D‐89081 Ulm Germany

   Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany