ISSN:
1432-2048
Keywords:
Key words: Antheraxanthin
;
Light adaptation
;
Mantoniella
;
Non-photochemical quenching of chlorophyll fluorescence
;
Violaxanthin cycle
;
Zeaxanthin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract. The prasinophycean alga Mantoniella squamata uses in vivo an incomplete violaxanthin cycle. Although the violaxanthin cycle in Mantoniella is capable of converting violaxanthin to zeaxanthin, in intact cells only antheraxanthin accumulates during periods of strong illumination. Antheraxanthin enhances non-photochemical quenching of chlorophyll fluorescence. Inhibition of antheraxanthin synthesis by the de-epoxidase inhibitor dithiothreitol abolishes increased thermal energy dissipation. Antheraxanthin-dependent non-photochemical quenching, like zeaxanthin-mediated non-photochemical quenching in higher plants, is uncoupler-sensitive. Mantoniella squamata cells cultivated at high light intensities contain higher amounts of violaxanthin than cells grown at low light. The increased violaxanthin-cycle pool size in high-light-grown Mantoniella cells is accompanied by higher de-epoxidation rates in the light and by a greater capacity to quench chlorophyll fluorescence non-photochemically. Antheraxanthin-dependent amplification of non-photochemical quenching is discussed in the light of recent models developed for zeaxanthin- and diatoxanthin-mediated enhanced heat dissipation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004250050364
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