Rice calcium‐dependent protein kinase OsCPK17 targets plasma membrane intrinsic protein and sucrose‐phosphate synthase and is required for a proper cold stress response |
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| Authors: | M Cecília Almadanim Bruno M Alexandre Margarida TG Rosa Helena Sapeta António E Leitão José C Ramalho TuKiet T Lam Sónia Negrão Isabel A Abreu M Margarida Oliveira |
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| Institution: | 1. Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal;2. Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal;3. Plant Stress and Biodiversity, Linking Landscape, Environment, Agriculture and Food (LEAF), Dept. Recursos Naturais, Ambiente e Território (DRAT), Instituto Superior de Agronomia, Universidade de Lisboa, Oeiras, Portugal;4. Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA;5. MS and Proteomics Resource, WM Keck Foundation Biotechnology Resource Laboratory, Yale University, New Haven, CT, USA;6. Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia |
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| Abstract: | Calcium‐dependent protein kinases (CDPKs) are involved in plant tolerance mechanisms to abiotic stresses. Although CDPKs are recognized as key messengers in signal transduction, the specific role of most members of this family remains unknown. Here, we test the hypothesis that OsCPK17 plays a role in rice cold stress response by analysing OsCPK17 knockout, silencing and overexpressing rice lines under low temperature. Altered OsCPK17 gene expression compromises cold tolerance performance, without affecting the expression of key cold stress‐inducible genes. A comparative phosphoproteomic approach led to the identification of six potential in vivo OsCPK17 targets, which are associated with sugar and nitrogen metabolism, and with osmotic regulation. To test direct interaction, in vitro kinase assays were performed, showing that the sucrose‐phosphate synthase OsSPS4 and the aquaporin OsPIP2;1/OsPIP2;6 are phosphorylated by OsCPK17 in a calcium‐dependent manner. Altogether, our data indicates that OsCPK17 is required for a proper cold stress response in rice, likely affecting the activity of membrane channels and sugar metabolism. |
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| Keywords: | abiotic stress CDPK phosphoproteomics phosphorylation signal transduction |
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