title: Two short sequences in OsNAR2.1 promoter are necessary for fully activating the nitrate induced gene expression in rice roots.
abstract: Nitrate is an essential nitrogen source and serves as a signal to control growth and gene expression in plants. In rice, OsNAR2.1 is an essential partner of multiple OsNRT2 nitrate transporters for nitrate uptake over low and high concentration range. Previously, we have reported that -311 bp upstream fragment from the translational start site in the promoter of OsNAR2.1 gene is the nitrate responsive region. To identify the cis-acting DNA elements necessary for nitrate induced gene expression, we detected the expression of beta-glucuronidase (GUS) reporter in the transgenic rice driven by the OsNAR2.1 promoter with different lengths and site mutations of the 311 bp region. We found that -129 to -1 bp region is necessary for the nitrate-induced full activation of OsNAR2.1. Besides, the site mutations showed that the 20 bp fragment between -191 and -172 bp contains an enhancer binding site necessary to fully drive the OsNAR2.1 expression. Part of the 20 bp fragment is commonly presented in the sequences of different promoters of both the nitrate induced NAR2 genes and nitrite reductase NIR1 genes from various higher plants. These findings thus reveal the presence of conserved cis-acting element for mediating nitrate responses in plants.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement.|MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement.|MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement.|MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Daimin
authors.initials: D
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement.|MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Miaoquan
authors.initials: M
authors.lastname: Song
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement.|MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement.|MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xu
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D000091285:Nitrate Transporters; D009566:Nitrates / Q000378:metabolism*; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics
chemical_list: D027321:Anion Transport Proteins; D000091285:Nitrate Transporters; D009566:Nitrates; D010940:Plant Proteins