title: Knockdown of the partner protein OsNAR2.1 for high-affinity nitrate transport represses lateral root formation in a nitrate-dependent manner.
abstract: The morphological plasticity of root systems is critical for plant survival, and understanding the mechanisms underlying root adaptation to nitrogen (N) fluctuation is critical for sustainable agriculture; however, the molecular mechanism of N-dependent root growth in rice remains unclear. This study aimed to identify the role of the complementary high-affinity NO3(-) transport protein OsNAR2.1 in NO3(-)-regulated rice root growth. Comparisons with wild-type (WT) plants showed that knockdown of OsNAR2.1 inhibited lateral root (LR) formation under low NO3(-) concentrations, but not under low NH4(+) concentrations. (15)N-labelling NO3(-) supplies (provided at concentrations of 0-10 mM) demonstrated that (i) defects in LR formation in mutants subjected to low external NO3(-) concentrations resulted from impaired NO3(-) uptake, and (ii) the mutants had significantly fewer LRs than the WT plants when root N contents were similar between genotypes. LR formation in osnar2.1 mutants was less sensitive to localised NO3(-) supply than LR formation in WT plants, suggesting that OsNAR2.1 may be involved in a NO3(-)-signalling pathway that controls LR formation. Knockdown of OsNAR2.1 inhibited LR formation by decreasing auxin transport from shoots to roots. Thus, OsNAR2.1 probably functions in both NO3(-) uptake and NO3(-)-signalling.
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Shuangjie
authors.initials: S
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Si
authors.initials: S
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Chenming
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Jingguang
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics*; D001692:Biological Transport; D055785:Gene Knockdown Techniques; D009154:Mutation; D009566:Nitrates / Q000378:metabolism*; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified
chemical_list: D027321:Anion Transport Proteins; D009566:Nitrates