Author: Cheng L.
Publisher: Oxford University Press
ISSN: 1460-2431
Source: Journal of Experimental Botany, Vol.54, Iss.381, 2003-01, pp. : 385-393
Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.
Abstract
The objective of this study was to determine xanthophyll cycle pool size and composition in response to N status and their relationships to non-photochemical quenching in apple leaves. Bench-grafted Fuji/M.26 trees were fertilized with different N concentrations (0–20 mM) in a modified Hoagland’s solution for 6 weeks to create a wide range of leaf N status (1–4.4 g m–2). Chlorophyll content, xanthophyll cycle pool size, lutein, total carotene, and neoxanthin on a leaf area basis all increased linearly with increasing leaf N. However, only the ratios of the xanthophyll cycle pool and of lutein to chlorophyll were higher in low N leaves than in high N leaves. Under high light at midday, both zeaxanthin (Z), expressed on a chlorophyll basis, and the percentage of the xanthophyll cycle pool present as Z, increased as leaf N decreased. Thermal dissipation of excitation energy, measured as non-photochemical quenching of chlorophyll fluorescence, was positively related to, whereas efficiency of excitation transfer and photosystem II quantum efficiency were negatively related to, Z, expressed on a chlorophyll basis or on a xanthophyll cycle pool basis. It is concluded that both xanthophyll cycle pool size (on a chlorophyll basis) and conversion of violaxanthin to zeaxanthin are enhanced in response to N limitation to dissipate excessive absorbed light under high irradiance.
Related content
Journal of Experimental Botany, Vol. 51, Iss. 351, 2000-10 ,pp. :
By Garcia-Plazaola JI Faria T Abadia J Abadia A Chaves MM Pereira JS
Journal of Experimental Botany, Vol. 48, Iss. 314, 1997-09 ,pp. :