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Leaf angle responds to nitrogen supply in eucalypt seedlings. Is it a photoprotective mechanism?


Close, DC and Beadle, CL, Leaf angle responds to nitrogen supply in eucalypt seedlings. Is it a photoprotective mechanism?, Tree Physiology, 26, (6) pp. 743-748. ISSN 0829-318X (2006) [Refereed Article]

DOI: doi:10.1093/treephys/26.6.743


We examined the adjustment of leaf angle (L θ) and foliar chlorophyll and xanthophyll chemistry in Eucalyptus nitens (Deane and Maiden) Maiden seedlings maintained in various nitrogen (N)-supply treatments over a 6-month period. Adjustment of L θ toward the vertical was greatest under conditions of foliar N deficiency and became incrementally more horizontal with increasing foliar N concentration. Photochemical efficiency (F v/F m) and quantum yield were lower in seedlings with low foliar N (low-N seedlings) in winter, but not in autumn. Low-N seedlings generally had low area-based chlorophyll concentrations and high xanthophyll-cycle conversion ratios, particularly during months of low temperature. Under mild temperature conditions, high concentrations of zeaxanthin and antheraxanthin were associated with lower electron transport rates (ETR). Incident light, F v/F m, ETR and total chlorophyll concentration were negatively correlated with L θ, with horizontal leaf orientation measured as 0° and vertical leaf orientation as 90°. Xanthophyll conversion ratio was positively correlated with L θ. Adjustments in L θ may play a role in photoprotection of E. nitens seedlings by assisting the leaf to balance its utilization and dissipation of energy. © 2006 Heron Publishing.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Plant physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Forestry
Objective Field:Hardwood plantations
UTAS Author:Close, DC (Professor Dugald Close)
ID Code:43063
Year Published:2006
Web of Science® Times Cited:11
Deposited By:Plant Science
Deposited On:2006-08-01
Last Modified:2007-05-03

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