Photoprotection in leaves of grapevines: Reponses of the xanthophyll cycle to alterations of light intensity

摘要

Under conditions of light intensities exceeding the photosynthetic use carotenoids of the xanthophyll cycle have been shown to be involved in the dissipation of excess energy. When, after a period of darkness, low light-adapted leaves (400 μmol.m~-2.s~-1) of cv. Orion vines were suddenly exposed to high light (800 μmol.m~-2.s~-1) the zeaxanthin (Z) content of the leaves increased significantly within 3 min at the expense of violaxanthin (V); a steady state was reached after ca. 20 min.