File(s) under permanent embargo
Revealing catastrophic failure of leaf networks under stress
journal contribution
posted on 2023-05-18, 23:35 authored by Timothy BrodribbTimothy Brodribb, BienaimA, D, Marmottant, PThe intricate patterns of veins that adorn the leaves of land plants are among the most important networks in biology. Water flows in these leaf irrigation networks under tension and is vulnerable to embolismforming cavitations, which cut off water supply, ultimately causing leaf death. Understanding the ways in which plants structure their vein supply network to protect against embolism-induced failure has enormous ecological and evolutionary implications, but until now there has been no way of observing dynamic failure in natural leaf networks. Herewe use a newoptical method that allows the initiation and spread of embolism bubbles in the leaf network to be visualized. Examining embolism-induced failure of architecturally diverse leaf networks, we found that conservative rules described the progression of hydraulic failure within veins. The most fundamental rule was that within an individual venation network, susceptibility to embolism always increased proportionally with the size of veins, and initial nucleation always occurred in the largest vein. Beyond this general framework, considerable diversity in the pattern of network failure was found between species, related to differences in vein network topology. The highest-risk networkwas found in a fern species, where single events caused massive disruption to leaf water supply, whereas safer networks in angiosperm leaves contained veins with composite properties, allowing a staged failure of water supply. These results reveal how the size structure of leaf venation is a critical determinant of the spread of embolism damage to leaves during drought.
Funding
Australian Research Council
History
Publication title
Proceedings of the National Academy of SciencesVolume
113Issue
17Pagination
4865-4869ISSN
0027-8424Department/School
School of Natural SciencesPublisher
National Academy of SciencesPlace of publication
United States of AmericaRights statement
Copyright 2016 National Academy of SciencesRepository Status
- Restricted