title: High light-dependent phosphorylation of photosystem II inner antenna CP29 in monocots is STN7 independent and enhances nonphotochemical quenching.
abstract: Phosphorylation of the photosystem II antenna protein CP29 has been reported to be induced by excess light and further enhanced by low temperature, increasing resistance to these stressing factors. Moreover, high light-induced CP29 phosphorylation was specifically found in monocots, both C3 and C4, which include the large majority of food crops. Recently, knockout collections have become available in rice (Oryza sativa), a model organism for monocots. In this work, we have used reverse genetics coupled to biochemical and physiological analysis to elucidate the molecular basis of high light-induced phosphorylation of CP29 and the mechanisms by which it exerts a photoprotective effect. We found that kinases and phosphatases involved in CP29 phosphorylation are distinct from those reported to act in State 1-State 2 transitions. In addition, we elucidated the photoprotective role of CP29 phosphorylation in reducing singlet oxygen production and enhancing excess energy dissipation. We thus established, in monocots, a mechanistic connection between phosphorylation of CP29 and nonphotochemical quenching, two processes so far considered independent from one another.
authors.affiliation: Dipartimento di Biotecnologie, Università di Verona, 37134 Verona, Italy (N.B., M.B., R.B.); andInstitute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany (S.B.).
authors.forename: Nico
authors.initials: N
authors.lastname: Betterle
authors.affiliation: Dipartimento di Biotecnologie, Università di Verona, 37134 Verona, Italy (N.B., M.B., R.B.); andInstitute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany (S.B.).
authors.forename: Matteo
authors.initials: M
authors.lastname: Ballottari
authors.affiliation: Dipartimento di Biotecnologie, Università di Verona, 37134 Verona, Italy (N.B., M.B., R.B.); andInstitute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany (S.B.).
authors.forename: Sacha
authors.initials: S
authors.lastname: Baginsky
authors.affiliation: Dipartimento di Biotecnologie, Università di Verona, 37134 Verona, Italy (N.B., M.B., R.B.); andInstitute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany (S.B.) roberto.bassi@univr.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bassi
mesh_terms: D001681:Biological Assay; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D007700:Kinetics; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D012275:Oryza / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects*; D010766:Phosphorylation / Q000187:drug effects / Q000528:radiation effects; D055668:Photochemical Processes / Q000528:radiation effects*; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D020524:Thylakoids / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D065146:Zeaxanthins / Q000378:metabolism
chemical_list: C069660:CP29 light harvesting complex; D045342:Light-Harvesting Protein Complexes; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D047428:Protein Kinase Inhibitors; D065146:Zeaxanthins