title: Seasonal changes of violaxanthin cycle pigment de-epoxidation in wintergreen and evergreen plants.
abstract: We studied carotenoids composition and the activities of the xanthophylls pigments in evergreen conifers (Abies sibirica, Juniperus communis, Picea obovata) and dwarf-shrub (Vaccinium vitis-idaea), and in wintergreen herbaceous plants (Ajuga reptans, Pyrola rotundifolia) growing near Syktyvkar (61°67(/) N 50°77(/) E). The carotenoid pool consisted mainly of following xanthophylls: lutein (70%), neoxanthin (7-10%) and a xanthophylls cycle component - violaxanthin (3-15%). Zeaxanthin and antheraxanthin were found in conifer samples collected in December-March while in other species - during all year. A direct connection between xanthophyll pigment de-epoxidation level and light energy thermal dissipation was shown only for boreal conifer species. It is proposed that zeaxanthin plays a central role in the dissipation of excess excitation energy (nonphotochemical quenching) in the antenna of photosystem II (PSII). We conclude that the increase in the extent of de-epoxidation is beneficial for the retention of PSII activity for conifers in early spring and for herbs in summer.
authors.affiliation: Institute of Biology, Komi Science Centre, Ural Branch of Russian Academy of Sciences, Syktyvkar, Russia. dymovao@ib.komisc.ru
authors.forename: Olga
authors.initials: O
authors.lastname: Dymova
authors.forename: Tamara
authors.initials: T
authors.lastname: Golovko
mesh_terms: D002338:Carotenoids / Q000737:chemistry* / Q000378:metabolism*; D014975:Lutein / Q000737:chemistry / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010944:Plants / Q000737:chemistry / Q000378:metabolism; D012621:Seasons; D064028:Tracheophyta / Q000737:chemistry* / Q000378:metabolism*; D024341:Xanthophylls / Q000737:chemistry / Q000378:metabolism; D065146:Zeaxanthins
chemical_list: D045332:Photosystem II Protein Complex; D024341:Xanthophylls; D065146:Zeaxanthins; C031140:antheraxanthin; D002338:Carotenoids; C005613:violaxanthin; C011947:neoxanthin; D014975:Lutein