Photosystem I is an early target of photoinhibition in barley illuminated at chilling temperatures

• Published in: Plant physiology (Bethesda) 1998-02, Vol.116 (2), p.755-764
• Main Authors: Tjus, S.E. (Royal Veterinary and Agricultural University, Fredriksberg, C, Copenhagen, Denmark.), Moller, B.L, Scheller, H.V
• Format: Article
• Language: English
• Subjects: ACIDE ASCORBIQUE; ACIDO ASCORBICO; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; AGENTES NOCIVOS; Agronomy. Soil science and plant productions; ASCORBIC ACID; AZUFRE; Barley; Biological and medical sciences; CHLOROPHYLLE; CHLOROPHYLLS; Chloroplasts; CIANUROS; CINC; CLOROFILAS; COBRE; COLD; Cold Temperature; COOLING; COPPER; CUIVRE; CYANIDES; CYANURE; DARKNESS; DEGRADACION; DEGRADATION; Economic plant physiology; ELECTRON TRANSFER; ENFRIAMIENTO; ENZYME INHIBITORS; ENZYMIC ACTIVITY; FACTEUR NUISIBLE; FER; FEUILLE; FOTOINHIBICION; FOTOSISTEMAS; FRIO; FROID; Fundamental and applied biological sciences. Psychology; HIERRO; HOJAS; Hordeum - radiation effects; HORDEUM VULGARE; INHIBIDORES DE ENZIMAS; INHIBITEUR D'ENZYME; INJURIOUS FACTORS; IRON; LEAVES; LIGHT; LIGHT INTENSITY; Light-Harvesting Protein Complexes; LUMIERE; LUZ; Metabolism; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; OBSCURIDAD; OBSCURITE; OXIDOREDUCTIONS; OXIRREDUCION; OXYDOREDUCTION; PEROXIDASAS; PEROXIDASES; PEROXYDASE; PHOTOINHIBITION; Photosynthesis, respiration. Anabolism, catabolism; Photosynthetic Reaction Center Complex Proteins - chemistry; Photosynthetic Reaction Center Complex Proteins - radiation effects; Photosystem I; Photosystem I Protein Complex; PHOTOSYSTEME; PHOTOSYSTEMS; PHYLLOQUINONE; Plant physiology and development; Plants; POTASIO; POTASSIUM; Potassium Chloride - chemistry; PROTEINAS; PROTEINE; PROTEINS; Reactive oxygen species; REFROIDISSEMENT; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; SOUFRE; STRESS RESPONSE; SULPHUR; SUPEROXIDE DISMUTASE; Superoxides; SUPEROXIDO DISMUTASA; SUPEROXYDE DISMUTASE; TEMPERATURE RESISTANCE; Thylakoids; VITAMIN K; VITAMINA K; VITAMINE K; Whole Plant, Environmental, and Stress Physiology; ZINC
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.116.2.755

Light-induced damage to photosystem I (PSI) was studied during low-light illumination of barley (Hordeum vulgare L.) at chilling temperatures. A 4-h illumination period induced a significant inactivation of PSI electron transport activity. Flash-induced P700 absorption decay measurements revealed progressive damage to (a) the iron-sulfur clusters FA and FB, (b) the iron-sulfur clusters FA, FB, and FX, and (c) the phylloquinone A1 and the chlorophyll A0 or P700 of the PSI electron acceptor chain. Light-induced PSI damage was also evidenced by partial degradation of the PSI-A and PSI-B proteins and was correlated with the appearance of smaller proteins. Aggravated photodamage was observed upon illumination of barley leaves infiltrated with KCN, which inhibits Cu,Zn-superoxide dismutase and ascorbate peroxidase. This indicates that the photodamage of PSI in barley observed during low-light illumination at chilling temperatures arises because the defense against active oxygen species by active oxygen-scavenging enzymes is insufficient at these specific conditions. The data obtained demonstrate that photoinhibition of PSI at chilling temperatures is an important phenomenon in a cold-tolerant plant species