title: DNA-binding protein phosphatase AtDBP1 acts as a promoter of flowering in Arabidopsis.
abstract: We provide evidence that AtDBP1 promotes flowering by regulating the transcript levels of several important integrators and floral meristem identity genes, including FLC, CO, SOC1, LFY, FT and FD. DNA-binding protein phosphatases (DBP) which exhibit both sequence specific DNA-binding and protein phosphatase 2C activities are important regulators that are involved in both the transcriptional and post-translational regulations. DBP factors are known to mediate susceptibility to potyviruses; however, whether they are involved in other processes is still unclear. In this study, under both long day (LD) and short day conditions, AtDBP1 overexpressing plants displayed early flowering, while the knock out mutants, atdbp1, exhibited a delay in flowering relative to the wild-type plants; both the overexpressing lines and atdbp1 mutants remained photoperiodic sensitive, indicating that AtDBP1 was involved in the autonomous pathway. AtDBP1 does not respond to vernalization at transcript level, and both AtDBP1 overexpressing plants and atdbp1 mutants remain responsive to vernalization, indicating that AtDBP1 may not be directly involved in vernalization. Real-time PCR analysis showed that AtDBP1 can suppress FLOWERING LOCUC C (FLC) expression, a key integrator of the autonomous and vernalization pathways, and enhance the expression levels of CONSTANS and FLOWERING LOCUC T, key regulators of the LD pathway. Furthermore, expression of floral meristem identity genes including SUPPRESSOR OF OVEREXPRESSION OF CO 1, LEAFY and FD was also promoted in AtDBP1 overexpressing plants. AtDBP1 transcription can be detected in root, leaf, stem, flower and silique. AtDBP1-GFP and YFP-AtDBP1 fusion protein were localized in the cytosol and nucleus. Our results provide the evidence demonstrating the effective role of AtDBP1 for flowering time regulation and report a novel function of DBP factors in planta besides in plant defense.
authors.affiliation: Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.|College of Life Science, Northeast Agricultural University, Harbin, 150030, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhai
authors.affiliation: College of Life Science, Northeast Agricultural University, Harbin, 150030, China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Ning
authors.affiliation: Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Wu
authors.affiliation: Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
authors.forename: Xingzheng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
authors.forename: Shixiang
authors.initials: S
authors.lastname: Lü
authors.affiliation: Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China. Xiazhj@neigaehrb.ac.cn.
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Xia
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D017440:Photoperiod; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C000592774:DBP1 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases
keywords: Autonomous pathway; DBP factors; FLOWERING LOCUC C; Protein phosphatase 2C; Vernalization pathway