title: Reduced Dormancy5 encodes a protein phosphatase 2C that is required for seed dormancy in Arabidopsis.
abstract: Seed dormancy determines germination timing and contributes to crop production and the adaptation of natural populations to their environment. Our knowledge about its regulation is limited. In a mutagenesis screen of a highly dormant Arabidopsis thaliana line, the reduced dormancy5 (rdo5) mutant was isolated based on its strongly reduced seed dormancy. Cloning of RDO5 showed that it encodes a PP2C phosphatase. Several PP2C phosphatases belonging to clade A are involved in abscisic acid signaling and control seed dormancy. However, RDO5 does not cluster with clade A phosphatases, and abscisic acid levels and sensitivity are unaltered in the rdo5 mutant. RDO5 transcript could only be detected in seeds and was most abundant in dry seeds. RDO5 was found in cells throughout the embryo and is located in the nucleus. A transcriptome analysis revealed that several genes belonging to the conserved PUF family of RNA binding proteins, in particular Arabidopsis PUMILIO9 (APUM9) and APUM11, showed strongly enhanced transcript levels in rdo5 during seed imbibition. Further transgenic analyses indicated that APUM9 reduces seed dormancy. Interestingly, reduction of APUM transcripts by RNA interference complemented the reduced dormancy phenotype of rdo5, indicating that RDO5 functions by suppressing APUM transcript levels.
authors.affiliation: Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xiang
authors.affiliation: Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Nakabayashi
authors.affiliation: Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
authors.forename: Jia
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany.
authors.forename: Fei
authors.initials: F
authors.lastname: He
authors.affiliation: Wageningen Seed Laboratory, Laboratory of Plant Physiology, Wageningen University, 6708 PB Wageningen, The Netherlands.
authors.forename: Leónie
authors.initials: L
authors.lastname: Bentsink
authors.affiliation: Department of Plant Breeding and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany soppe@mpipz.mpg.de.
authors.forename: Wim J J
authors.initials: WJ
authors.lastname: Soppe
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018525:Germination; D009154:Mutation; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D057445:Plant Dormancy; D010937:Plant Growth Regulators / Q000378:metabolism*; D030821:Plants, Genetically Modified; D000071636:Protein Phosphatase 2C; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012639:Seeds / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction
chemical_list: C000602071:APUM9 protein, Arabidopsis; D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D016601:RNA-Binding Proteins; D000040:Abscisic Acid; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C; C000602072:RDO5 protein, Arabidopsis