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Photoprotective carotenoids and antioxidants are more affected by canopy position than by nitrogen supply in 21-year-old Pinus radiata

journal contribution
posted on 24.10.2019, 00:00 by Sabine Tausz-PoschSabine Tausz-Posch, CR Warren, MA Adams, H Guttenberger
Photoprotection, light harvesting and light utilisation were investigated as a function of variation in N supply and canopy position in 21-year-old Pinus radiata D. Don. Chlorophyll fluorescence, gas exchange and photoprotective compounds were measured on lower, middle and upper canopy needles in trees receiving N fertiliser and in control trees not receiving N fertiliser. Irrespective of canopy height, additional N increased the light-harvesting capacity through greater contents of chlorophyll, neoxanthin and lutein, but did not affect light-utilisation processes, such as effective quantum yield of PSII or rates of net CO 2 assimilation. Additional N fertiliser did not affect the concentrations of the measured photoprotective carotenoids (violaxanthin, antheraxanthin, zeaxanthin, α-carotene and β-carotene) or antioxidants (ascorbic acid, glutathione and α-tocopherol); however, carotenoids and antioxidants were strongly affected by canopy height and increased in concentration with increasing canopy height. The present study found that pools of photoprotective carotenoids and antioxidants were not driven by imbalances in light-harvesting and light-utilisation processes, but rather by gradients in light. © CSIRO 2008.

Funding

Other

History

Volume

35

Issue

6

Start Page

470

End Page

482

Number of Pages

13

ISSN

1445-4408

Publisher

CSIRO

Peer Reviewed

Yes

Open Access

No

External Author Affiliations

Karl-Franzens-University Graz, Austria; University of Sydney; University of New South Wales

Era Eligible

Yes

Journal

Functional Plant Biology