J. Exp. Bot.-2011-McAdam-195-203.pdf (270.94 kB)
Augmentation of abscisic acid (ABA) levels by drought does not induce short-term stomatal sensitivity to CO2 in two divergent conifer species
journal contribution
posted on 2023-05-17, 04:26 authored by McAdam, SAM, Timothy BrodribbTimothy Brodribb, John RossJohn Ross, Gregory JordanGregory JordanThe stomata of conifers display very little short-term response to changes in atmospheric CO2 concentration (Ca), whereas the stomatal responses of angiosperms to Ca increase in response to water stress. This behaviour of angiosperm stomata appears to be dependent on foliar levels of abscisic acid (ABAf). Here two alternative explanations for the stomatal insensitivity of conifers to Ca are tested: that conifers have either low ABAf or a higher or absent threshold for ABA-induced sensitivity. The responsiveness of stomatal conductance (gs) to a sequence of transitions in Ca (386, 100, and 600μmol mol -1) was recorded over a range of ABAf in an angiosperm and two divergent conifer species. The different ABA levels were induced by a mild drought cycle. Although the angiosperm and conifer species showed similar proportional increases in ABAf following drought, conifer stomata remained insensitive to changes in Ca whereas angiosperm stomata showed enhanced sensitivity with increasing ABAf. The conifers, however, had much higher ABAf prior to drought than the angiosperm species, suggesting that non-sensitivity to Ca in these conifers was due to an absent or inactive response/signalling pathway rather than insufficient ABAf. © 2010 The Author.
History
Publication title
Journal of Experimental BotanyVolume
62Pagination
195-203ISSN
0022-0957Department/School
School of Natural SciencesPublisher
Oxford Univ PressPlace of publication
Great Clarendon St, Oxford, England, Ox2 6DpRights statement
Licenced under Creative Commons Attribution - NonCommercial 2.5 Generic (CC BY-NC 2.5) http://creativecommons.org/licenses/by-nc/2.5/Repository Status
- Open