40
IRUS TotalDownloads
Altmetric
Long-term water stress leads to acclimation of drought sensitivity of photosynthetic capacity in xeric but not riparian Eucalyptus species
Title: | Long-term water stress leads to acclimation of drought sensitivity of photosynthetic capacity in xeric but not riparian Eucalyptus species |
Authors: | Zhou, S-X Medlyn, BE Prentice, IC |
Item Type: | Journal Article |
Abstract: | Background and Aims Experimental drought is well documented to induce a decline in photosynthetic capacity. However, if given time to acclimate to low water availability, the photosynthetic responses of plants to low soil moisture content may differ from those found in short-term experiments. This study aims to test whether plants acclimate to long-term water stress by modifying the functional relationships between photosynthetic traits and water stress, and whether species of contrasting habitat differ in their degree of acclimation. Methods Three Eucalyptus taxa from xeric and riparian habitats were compared with regard to their gas exchange responses under short- and long-term drought. Photosynthetic parameters were measured after 2 and 4 months of watering treatments, namely field capacity or partial drought. At 4 months, all plants were watered to field capacity, then watering was stopped. Further measurements were made during the subsequent ‘drying-down’, continuing until stomata were closed. Key Results Two months of partial drought consistently reduced assimilation rate, stomatal sensitivity parameters (g1), apparent maximum Rubisco activity (V′cmaxVcmax′) and maximum electron transport rate (J′maxJmax′). Eucalyptus occidentalis from the xeric habitat showed the smallest decline in V′cmaxVcmax′ and J′maxJmax′; however, after 4 months, V′cmaxVcmax′ and J′maxJmax′ had recovered. Species differed in their degree of V′cmaxVcmax′ acclimation. Eucalyptus occidentalis showed significant acclimation of the pre-dawn leaf water potential at which the V′cmaxVcmax′ and ‘true’ Vcmax (accounting for mesophyll conductance) declined most steeply during drying-down. Conclusions The findings indicate carbon loss under prolonged drought could be over-estimated without accounting for acclimation. In particular, (1) species from contrasting habitats differed in the magnitude of V′cmax reduction in short-term drought; (2) long-term drought allowed the possibility of acclimation, such that V′cmax reduction was mitigated; (3) xeric species showed a greater degree of V′cmax acclimation; and (4) photosynthetic acclimation involves hydraulic adjustments to reduce water loss while maintaining photosynthesis. |
Issue Date: | 22-Oct-2015 |
Date of Acceptance: | 10-Sep-2015 |
URI: | http://hdl.handle.net/10044/1/56802 |
DOI: | https://dx.doi.org/10.1093/aob/mcv161 |
ISSN: | 1095-8290 |
Publisher: | Oxford University Press (OUP) |
Start Page: | 133 |
End Page: | 144 |
Journal / Book Title: | Annals of Botany |
Volume: | 117 |
Issue: | 1 |
Copyright Statement: | This is a pre-copyedited, author-produced PDF of an article accepted for publication in Annals of Botany following peer review. The version of record Shuang-Xi Zhou, Belinda E. Medlyn, Iain Colin Prentice; Long-term water stress leads to acclimation of drought sensitivity of photosynthetic capacity in xeric but not riparian Eucalyptus species, Annals of Botany, Volume 117, Issue 1, 1 January 2016, Pages 133–144, is available online at: https://dx.doi.org/10.1093/aob/mcv161 |
Sponsor/Funder: | AXA Research Fund |
Funder's Grant Number: | AXA Chair Programme in Biosphere and Climate Impacts |
Keywords: | Science & Technology Life Sciences & Biomedicine Plant Sciences Drought acclimation photosynthesis water stress V-cmax J(max) water use efficiency stomatal conductance mesophyll conductance Huber value hydraulic adjustment riparian Eucalyptus camaldulensis xeric Eucalyptus occidentalis DECREASED RUBISCO ACTIVITY STOMATAL CONDUCTANCE MESOPHYLL CONDUCTANCE QUERCUS-ILEX PHYSIOLOGICAL-RESPONSES BIOCHEMICAL LIMITATIONS DIFFUSION CONDUCTANCE THROUGHFALL EXCLUSION GAS-EXCHANGE C-3 PLANTS Jmax Vcmax Acclimatization Carbon Dioxide Carbon Isotopes Dehydration Droughts Ecosystem Eucalyptus Light Photosynthesis Plant Leaves Principal Component Analysis Species Specificity Water 0607 Plant Biology 0602 Ecology Plant Biology & Botany |
Publication Status: | Published |
Appears in Collections: | Department of Life Sciences Grantham Institute for Climate Change Faculty of Natural Sciences |