title: BcNRT1, a plasma membrane-localized nitrate transporter from non-heading Chinese cabbage.
abstract: A nitrate transporter, BcNRT1, was isolated from non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) cultivar 'Suzhouqing'. The full-length cDNA was obtained using the rapid amplification of cDNA ends technique and contains an open reading frame of 1,770 bp that predicts a protein of 589 acid residues that possesses 12 putative transmembrane domains. Using the GUS marker gene driven by the BcNRT1 promoter, we found BcNRT1 expression to be concentrated in primary and lateral root tips and in shoots of transgenic Arabidopsis plants. The YFP fused to BcNRT1 and transformed into cabbage protoplasts indicated that BcNRT1 was localized to the plasma membrane. The expression of BcNRT1 in roots was induced by exposure to 25 mM nitrate, and the BcNRT1 cRNA heterologously expressed in Xenopus laevis oocytes showed nitrate conductance when nitrate was included in the medium. Moreover, mutant chl1-5 plants harboring 35S::BcNRT1 showed sensitivity to chlorate treatment and exhibited restored nitrate uptake. In conclusion, the results indicate that BcNRT1 functions as a low affinity nitrate transporter in non-heading Chinese cabbage.
authors.affiliation: College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xuedong
authors.initials: X
authors.lastname: Yang
authors.forename: Feifei
authors.initials: F
authors.lastname: Sun
authors.forename: Aisheng
authors.initials: A
authors.lastname: Xiong
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Kong
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Jinyan
authors.initials: J
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Dai
authors.forename: Xiudong
authors.initials: X
authors.lastname: Xia
authors.forename: Xilin
authors.initials: X
authors.lastname: Hou
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D027321:Anion Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D001937:Brassica / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005816:Genetic Complementation Test; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D000091285:Nitrate Transporters; D009566:Nitrates / Q000378:metabolism / Q000494:pharmacology; D009865:Oocytes / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D021381:Protein Transport; D011523:Protoplasts / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014982:Xenopus laevis
chemical_list: D027321:Anion Transport Proteins; D000091285:Nitrate Transporters; D009566:Nitrates; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D005966:Glucuronidase