Journal article
CO2 enrichment inhibits shoot nitrate assimilation in C3 but not C4 plants and slows growth under nitrate in C3 plants
Ecology (Durham), Vol.93(2), pp.355-367
02/2012
Handle:
https://hdl.handle.net/2376/113261
PMID: 22624317
Abstract
The CO
2
concentration in Earth's atmosphere may double during this century. Plant responses to such an increase depend strongly on their nitrogen status, but the reasons have been uncertain. Here, we assessed shoot nitrate assimilation into amino acids via the shift in shoot CO
2
and O
2
fluxes when plants received nitrate instead of ammonium as a nitrogen source (ΔAQ). Shoot nitrate assimilation became negligible with increasing CO
2
in a taxonomically diverse group of eight C
3
plant species, was relatively insensitive to CO
2
in three C
4
species, and showed an intermediate sensitivity in two C
3
-C
4
intermediate species. We then examined the influence of CO
2
level and ammonium vs. nitrate nutrition on growth, assessed in terms of changes in fresh mass, of several C
3
species and a Crassulacean acid metabolism (CAM) species. Elevated CO
2
(720 μmol CO
2
/mol of all gases present) stimulated growth or had no effect in the five C
3
species tested when they received ammonium as a nitrogen source but inhibited growth or had no effect if they received nitrate. Under nitrate, two C
3
species grew faster at sub-ambient (∼310 μmol/mol) than elevated CO
2
. A CAM species grew faster at ambient than elevated or sub-ambient CO
2
under either ammonium or nitrate nutrition. This study establishes that CO
2
enrichment inhibits shoot nitrate assimilation in a wide variety of C
3
plants and that this phenomenon can have a profound effect on their growth. This indicates that shoot nitrate assimilation provides an important contribution to the nitrate assimilation of an entire C
3
plant. Thus, rising CO
2
and its effects on shoot nitrate assimilation may influence the distribution of C
3
plant species.
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Details
- Title
- CO2 enrichment inhibits shoot nitrate assimilation in C3 but not C4 plants and slows growth under nitrate in C3 plants
- Creators
- Arnold J Bloom - Department of Plant Sciences, University of California, Davis, California 95616 USAJose Salvador Rubio Asensio - Department of Plant Sciences, University of California, Davis, California 95616 USALesley Randall - Department of Plant Sciences, University of California, Davis, California 95616 USAShimon Rachmilevitch - Department of Plant Sciences, University of California, Davis, California 95616 USAAsaph B Cousins - Department of Plant Sciences, University of California, Davis, California 95616 USAEli A Carlisle - Department of Plant Sciences, University of California, Davis, California 95616 USA
- Publication Details
- Ecology (Durham), Vol.93(2), pp.355-367
- Academic Unit
- Biological Sciences, School of
- Publisher
- Ecological Society of America
- Identifiers
- 99900547540201842
- Language
- English
- Resource Type
- Journal article