title: The calcium sensor CBL7 modulates plant responses to low nitrate in Arabidopsis.
abstract: Calcium (Ca(2+)) serves as a critical messenger in a number of adaptation and developmental processes. In plants, CBL family represents a unique group of calcium sensors that decodes calcium signals. Several CBL members have been functionally characterized in the model plant Arabidopsis thaliana, but the role of CBL7 remains unknown. Here, we report that CBL7 is involved in the regulation of low-nitrate response in Arabidopsis. Expression of CBL7 was predominant in the root of young seedlings and substantially induced by nitrate starvation. Cbl7 mutant was more inhibited in root growth upon nitrate starvation compared to the wild-type. Interestingly, the growth arrest of cbl7 under low-nitrate conditions relied on acidic pH. Further analyses revealed that expression of two high-affinity nitrate transporter genes, NRT2.4 and NRT2.5, was down-regulated in cbl7 under nitrogen-starvation condition. Accordingly, the cbl7 mutant plants retained lower nitrate content than wild-type plants under low-nitrate condition. Taken together, our results uncover a novel role of CBL7 in the response to nitrate deficiency in Arabidopsis.
authors.affiliation: State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, PR China; Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, 73072, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ma
authors.affiliation: Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, 73072, USA.
authors.forename: Ren-Jie
authors.initials: RJ
authors.lastname: Tang
authors.affiliation: Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, 73072, USA; NJU-NJFU Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing, 210093, PR China.
authors.forename: Xiao-Jiang
authors.initials: XJ
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, PR China. Electronic address: smwang@lzu.edu.cn.
authors.forename: Suo-Min
authors.initials: SM
authors.lastname: Wang
authors.affiliation: Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, 73072, USA; NJU-NJFU Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing, 210093, PR China. Electronic address: sluan@berkeley.edu.
authors.forename: Sheng
authors.initials: S
authors.lastname: Luan
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C000605947:CBL7 protein, Arabidopsis; D002135:Calcium-Binding Proteins; D009566:Nitrates; D009584:Nitrogen; D002118:Calcium
keywords: CBL7; Low nitrate; NRT2.4; NRT2.5