title: Impairment of the photorespiratory pathway accelerates photoinhibition of photosystem II by suppression of repair but not acceleration of damage processes in Arabidopsis.
abstract: Oxygenation of ribulose-1,5-bisphosphate catalyzed by Rubisco produces glycolate-2-P. The photorespiratory pathway, which consists of photorespiratory carbon and nitrogen cycles, metabolizes glycolate-2-P to the Calvin cycle intermediate glycerate-3-P and is proposed to be important for avoiding photoinhibition of photosystem II (PSII), especially in C3 plants. We show here that mutants of Arabidopsis (Arabidopsis thaliana) with impairment of ferredoxin-dependent glutamate synthase, serine hydroxymethyltransferase, glutamate/malate transporter, and glycerate kinase had accelerated photoinhibition of PSII by suppression of the repair of photodamaged PSII and not acceleration of the photodamage to PSII. We found that suppression of the repair process was attributable to inhibition of the synthesis of the D1 protein at the level of translation. Our results suggest that the photorespiratory pathway helps avoid inhibition of the synthesis of the D1 protein, which is important for the repair of photodamaged PSII upon interruption of the Calvin cycle.
authors.affiliation: Molecular Plant Physiology Group and Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biological Sciences, Australian National University, Canberra, ACT 2601, Australia. shunichi.takahashi@anu.edu.tr
authors.forename: Shunichi
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hermann
authors.initials: H
authors.lastname: Bauwe
authors.forename: Murray
authors.initials: M
authors.lastname: Badger
mesh_terms: D017360:Arabidopsis / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002245:Carbon Dioxide / Q000378:metabolism; D008027:Light; D008954:Models, Biological; D010788:Photosynthesis / Q000502:physiology*; D045332:Photosystem II Protein Complex / Q000037:antagonists & inhibitors*; D014176:Protein Biosynthesis / Q000502:physiology; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D045332:Photosystem II Protein Complex; D002245:Carbon Dioxide; D012273:Ribulose-Bisphosphate Carboxylase