Charles Darwin University

CDU eSpace
Institutional Repository

 
CDU Staff and Student only
 

Stable Isotopes Reveal the Contribution of Corticular Photosynthesis to Growth in Branches of Eucalyptus miniata

Cernusak, Lucas A. and Hutley, Lindsay B. (2011). Stable Isotopes Reveal the Contribution of Corticular Photosynthesis to Growth in Branches of Eucalyptus miniata. Plant Physiology,155(1):515-523.

Document type: Journal Article

IRMA ID 82057923xPUB1
Title Stable Isotopes Reveal the Contribution of Corticular Photosynthesis to Growth in Branches of Eucalyptus miniata
Author Cernusak, Lucas A.
Hutley, Lindsay B.
Journal Name Plant Physiology
Publication Date 2011
Volume Number 155
Issue Number 1
ISSN 0032-0889   (check CDU catalogue open catalogue search in new window)
Scopus ID 2-s2.0-78650977369
Start Page 515
End Page 523
Total Pages 9
Place of Publication United States
Publisher American Society of Plant Biologists
HERDC Category C1 - Journal Article (DIISR)
Abstract The deciduous bark habit is widespread in the woody plant genus Eucalyptus. Species with deciduous bark seasonally shed a layer of dead bark, thereby maintaining smooth-bark surfaces on branches and stems as they age and increase in diameter. This has a significant cost in terms of fire protection, because smooth-barked species have thinner bark than rough-barked species that accumulate successive layers of dead bark. Eucalypts are closely associated with fire, suggesting that the smooth-bark habit must also provide a significant benefit.We suggest that this benefit is corticular photosynthesis. To test this, we quantified the contribution of corticular photosynthesis to wood production in smooth-barked branches of Eucalyptus miniata growing in tropical savanna in northern Australia. We covered branch sections with aluminum foil for 4 years to block corticular photosynthesis and then compared the oxygen and carbon stable isotope composition of foil-covered and uncovered branch sections. We developed theory to calculate the proportion of wood constructed from corticular photosynthate and the mean proportional refixation rate during corticular photosynthesis from the observed isotopic differences. Coverage with aluminum foil for 4 years increased wood δ 13C by 0.5‰(P = 0.002, n = 6) and wood δ 18O by 0.5‰ (P = 0.02, n = 6). Based on these data, we estimated that 11% ± 3% of wood in the uncovered branch sections was constructed from corticular photosynthate, with a mean δ 13C of -34.8‰, and that the mean proportional refixation rate during corticular photosynthesis was 0.71 ± 0.15. This demonstrates that corticular photosynthesis makes a significant contribution to the carbon economy of smooth-barked eucalypts.
DOI http://dx.doi.org/10.1104/pp.110.163337   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)
 
Versions
Version Filter Type
Access Statistics: 29 Abstract Views  -  Detailed Statistics
Created: Fri, 17 Jan 2014, 00:45:52 CST