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Minimum hydraulic safety leads to maximum water-use efficiency in a forage grass
Citation
Holloway-Phillips, M and Brodribb, TJ, Minimum hydraulic safety leads to maximum water-use efficiency in a forage grass, Plant, Cell and Environment, 34, (2) pp. 302-313. ISSN 0140-7791 (2011) [Refereed Article]
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Copyright Statement
Copyright © 2010 The definitive published version is available online at: http://onlinelibrary.wiley.com/
DOI: doi:10.1111/j.1365-3040.2010.02244.x
Abstract
Understanding how water-use regulation relates to biomass
accumulation is imperative for improving crop production
in water-limited environments. Here, we examine how
the vulnerability of xylem to water stress-induced cavitation
and the coordination between water transport capacity and
assimilation (A) influences diurnal water-use efficiency
(WUE) and dry-matter production in Lolium perenne L. –
a commercial forage grass. Plants were exposed to a range
of water stresses, causing up to 90% leaf death, by withholding
water and then rewatering to observe the recovery
process. Leaf hydraulic conductance (Kleaf) declined to 50%
of maximum at a leaf water potential (yleaf) of -1 MPa,
whereas complete stomatal closure occurred well after
this point, at -2.35 MPa, providing no protection against
hydraulic dysfunction. Instantaneous A remained maximal
until >70% of hydraulic conductivity had been lost. Poststress
rewatering showed that 95% loss of Kleaf could be
incurred before the recovery of gas exchange exceeded 1 d,
with a rapid transition to leaf death after this point. Plants
exposed to sustained soil water deficits through restricted
nightly watering regimes did not suffer cumulative losses in
Kleaf; instead, yleaf and gas exchange recovered diurnally.
The effect was improved WUE during the day and optimal
yleaf during the night for the maintenance of growth.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | grass; hydraulic conductivity; production; safety margin; stomatal regulation; water stress; water-use efficiency; xylem vulnerability. |
| Research Division: | Biological Sciences |
| Research Group: | Evolutionary biology |
| Research Field: | Biological adaptation |
| Objective Division: | Environmental Management |
| Objective Group: | Terrestrial systems and management |
| Objective Field: | Terrestrial biodiversity |
| UTAS Author: | Holloway-Phillips, M (Miss Meisha-Marika Holloway-Phillips) |
| UTAS Author: | Brodribb, TJ (Professor Tim Brodribb) |
| ID Code: | 71954 |
| Year Published: | 2011 |
| Web of Science® Times Cited: | 34 |
| Deposited By: | Plant Science |
| Deposited On: | 2011-08-16 |
| Last Modified: | 2012-06-18 |
| Downloads: | 1 View Download Statistics |
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