A hydraulic explanation for size-specific plant shrinkage: developmental hydraulic sectoriality

Salguero-Gomez, Roberto and Casper, Brenda B. (2011) A hydraulic explanation for size-specific plant shrinkage: developmental hydraulic sectoriality. New Phytologist, 189 1: 229-240. doi:10.1111/j.1469-8137.2010.03447.x

Author Salguero-Gomez, Roberto
Casper, Brenda B.
Title A hydraulic explanation for size-specific plant shrinkage: developmental hydraulic sectoriality
Journal name New Phytologist   Check publisher's open access policy
ISSN 0028-646X
Publication date 2011-01-01
Year available 2011
Sub-type Article (original research)
DOI 10.1111/j.1469-8137.2010.03447.x
Volume 189
Issue 1
Start page 229
End page 240
Total pages 12
Place of publication Oxford, United Kingdom
Publisher Wiley-Blackwell Publishing Ltd.
Language eng
Formatted abstract
•  While great attention has been paid to the mechanisms controlling plant growth, much less is known about why and how plants shrink. The modular design of plants may facilitate the independence of modules if the xylem vasculature is hydraulically sectored. We examined the hydraulic connectivity of modules comprising juveniles and adults of the aridland chamaephyte Cryptantha flava (Boraginaceae), motivated by the observation that rosette mortality is spatially aggregated in adults, but not in juveniles.

•  We explored spatial patterns of leaf wilting after clipping a single lateral root, tracked physiological dyes taken up by a single root, and measured within-plant variation in leaf water potentials after watering a portion of the root system. We then measured xylem anatomical features related to hydraulic connectivity.

•  Our approaches revealed hydraulic integration in juveniles but hydraulic sectoriality in adults. We attribute such developmental changes to increasing distances between xylem bundles, and larger xylem lumen and heartwood areas as plants age.

•  We have demonstrated functional sectoriality in a desert chamaephyte, and report the mechanism by which sectoriality occurs, offering a hydraulic explanation for the death of whole plant portions resulting in shrinkage of large plants, and for the high occurrence of this design in deserts. 
Keyword Cryptantha flava
Distance to xylem
Dye tracking
Great Basin desert
Hydraulic integration
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biological Sciences Publications
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