title: Chilling stress and hydrogen peroxide accumulation in Chrysanthemum morifolium and Spathiphyllum lanceifolium. Involvement of chlororespiration.
abstract: Plants of Chrysanthemum morifolium (sun species) and Spathiphyllum lanceifolium (shade species) were used to study the effects of chilling stems under high illumination. The stress conditions resulted in a greater accumulation of H2O2in C. morifolium than in S. lanceifolium, and in the down-regulation of photosynthetic linear electron transport in both species. However, only a slight decrease in the maximal quantum yield of PSII was observed under unfavorable conditions in both species, suggesting that mechanisms exist in the chloroplasts that dissipate excess excitation energy and prevent damage to the photosynthetic apparatus. Additionally, changes were observed in the PGR5 polypeptide involved in cyclic electron flow around PSI and in chlororespiratory enzymes (plastidial NDH complex and PTOX). The level of PGR5 increased significantly only in chilled plants of C. morifolium, whereas the levels of the PTOX and NDH-H polypeptide of the plastidial NDH complex and the NDH activity increased significantly only in chilled plants of S. lanceifolium. These findings suggest that the cyclic electron flow involving PGR5 is more active in C. morifolium, while in S. lanceifolium, other mechanisms involving chlororespiratory enzymes are stimulated in response to chilling and high light, resulting in less H2O2being accumulated in leaves.
authors.affiliation: Departamento de Biología Vegetal, Facultad de Biología, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain.
authors.forename: Miriam
authors.initials: M
authors.lastname: Paredes
authors.affiliation: Departamento de Biología Vegetal, Facultad de Biología, Universidad de Murcia, Campus de Espinardo, E-30100 Murcia, Spain. Electronic address: mjquiles@um.es.
authors.forename: María José
authors.initials: MJ
authors.lastname: Quiles
mesh_terms: D029064:Araceae / Q000378:metabolism*; D019069:Cell Respiration; D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D031202:Chrysanthemum / Q000378:metabolism*; D003080:Cold Temperature; D004583:Electrons; D005453:Fluorescence; D006861:Hydrogen Peroxide / Q000378:metabolism*; D015151:Immunoblotting; D009243:NAD / Q000378:metabolism; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D010971:Plastoquinone / Q000378:metabolism; D011789:Quantum Theory; D011808:Quinone Reductases / Q000378:metabolism; D013312:Stress, Physiological; D020524:Thylakoids / Q000201:enzymology
chemical_list: D010455:Peptides; D045332:Photosystem II Protein Complex; D009243:NAD; D002734:Chlorophyll; D006861:Hydrogen Peroxide; D011808:Quinone Reductases; C073412:sulfide quinone reductase; D010971:Plastoquinone
keywords: Chrysanthemum morifolium; NDH complex; PGR5; PTOX; Photosynthesis; Spathiphyllum lanceifolium