Počet záznamů: 1

Magnetic field protects plants against high light by slowing down production of singlet oxygen

  1. 1.
    0359476 - UEK-B 2012 RIV DK eng J - Článek v odborném periodiku
    Hakala-Yatkin, M. - Sarvikas, P. - Paturi, P. - Mattila, H. - Tyystjärvi, T. - Nedbal, Ladislav - Tyystjärvi, E.
    Magnetic field protects plants against high light by slowing down production of singlet oxygen.
    Physiologia Plantarum. Roč. 142, č. 1 (2011), s. 26-34 ISSN 0031-9317
    Výzkumný záměr: CEZ:AV0Z60870520
    Klíčová slova: photosynthetic reaction-center * Photosystem-II * alpha-tocopherol * environmental-stress * manganese complex * evolving complex * oxidative stress
    Kód oboru RIV: EH - Ekologie - společenstva
    Impakt faktor: 3.112, rok: 2011

    Recombination of the primary radical pair of photosystem II (PSII) of photosynthesis may produce the triplet state of the primary donor of PSII. Triplet formation is potentially harmful because chlorophyll triplets can react with molecular oxygen to produce the reactive singlet oxygen (1O(2)). The yield of 1O(2) is expected to be directly proportional to the triplet yield and the triplet yield of charge recombination can be lowered with a magnetic field of 100-300 mT. In this study, we illuminated intact pumpkin leaves with strong light in the presence and absence of a magnetic field and found that the magnetic field protects against photoinhibition of PSII. The result suggests that radical pair recombination is responsible for significant part of 1O(2) production in the chloroplast. The magnetic field effect vanished if leaves were illuminated in the presence of lincomycin, an inhibitor of chloroplast protein synthesis, or if isolated thylakoid membranes were exposed to light. These data, in turn, indicate that 1O(2) produced by the recombination of the primary charge pair is not directly involved in photoinactivation of PSII but instead damages PSII by inhibiting the repair of photoinhibited PSII. We also found that an Arabidopsis thaliana mutant lacking alpha-tocopherol, a scavenger of 1O(2), is more sensitive to photoinhibition than the wild-type in the absence but not in the presence of lincomycin, confirming that the target of 1O(2) is the repair mechanism.
    Trvalý link: http://hdl.handle.net/11104/0197260