Document Detail


Oxygen isotope composition of CAM and C3 Clusia species: non-steady-state dynamics control leaf water 18O enrichment in succulent leaves.
MedLine Citation:
PMID:  18684241     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Leaf gas exchange and leaf water (18)O enrichment (Delta(18)O(L)) were measured in three Clusia species under field conditions during dry and wet seasons and in Miconia argentea during the dry season in the Republic of Panama. During the dry season, all three Clusia species used crassulacean acid metabolism (CAM); during the wet season Clusia pratensis operated in the C(3) mode, while Clusia uvitana and Clusia rosea used CAM. Large departures from isotopic steady state were observed in daytime Delta(18)O(L) of the Clusia species, especially during the dry season. In contrast, daytime Delta(18)O(L) was near isotopic steady state in the C(3) tree M. argentea. Across the full data set, non-steady-state predictions explained 49% of variation in observed Delta(18)O(L), whereas steady-state predictions explained only 14%. During the wet season, when Delta(18)O(L) could be compared with Clusia individuals operating in both C(3) and CAM modes, steady-state and non-steady-state models gave contrasting predictions with respect to interspecific variation in daytime Delta(18)O(L). The observed Delta(18)O(L) pattern matched that predicted for the non-steady state. The results provided a clear example of how non-steady-state control of leaf water (18)O dynamics can shift the slope of the relationship between transpiration rate and daytime Delta(18)O(L) from negative to positive.
Authors:
Lucas A Cernusak; Monica Mejia-Chang; Klaus Winter; Howard Griffiths
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-09-02
Journal Detail:
Title:  Plant, cell & environment     Volume:  31     ISSN:  1365-3040     ISO Abbreviation:  Plant Cell Environ.     Publication Date:  2008 Nov 
Date Detail:
Created Date:  2008-10-27     Completed Date:  2008-11-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9309004     Medline TA:  Plant Cell Environ     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1644-62     Citation Subset:  IM    
Affiliation:
Smithsonian Tropical Research Institute, Balboa, Ancon, Republic of Panama. lucas.cernusak@cdu.edu.au
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MeSH Terms
Descriptor/Qualifier:
Clusia / metabolism*
Models, Biological
Oxygen Isotopes / metabolism*
Photosynthesis
Plant Leaves / metabolism*
Plant Stems / metabolism
Plant Transpiration*
Seasons
Temperature
Water / metabolism*
Chemical
Reg. No./Substance:
0/Oxygen Isotopes; 7732-18-5/Water

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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