title: Gene characterization and transcription analysis of two new ammonium transporters in pear rootstock (Pyrus betulaefolia).
abstract: Ammonium is the primarily nitrogen source for plant growth, but the molecular basis of ammonium acquisition in fruit species remains poorly understood. In this study, we report on the characterization of two new ammonium transporters (AMT) in the perennial tree Pyrus betulaefolia. In silico analyses and yeast complementation assays revealed that both PbAMT1;3 and PbAMT1;5 can be classified in the AMT1 sub-family. The specific expression of PbAMT1;3 in roots and of PbAMT1;5 in leaves indicates that they have diverse functions in ammonium uptake or transport in P. betulaefolia. Their expression was strongly influenced by ammonium availability. In addition, the transcript level of PbAMT1;5 was significantly affected by the diurnal cycle and senescence hormones. They conferred the ability to uptake nitrogen to the yeast strain 31019b; however, the (15)NH4 (+) uptake kinetics of PbAMT1;3 were different from those of PbAMT1;5. Indeed, PbAMT1;3 had a higher affinity for (15)NH4 (+), and pH changes were associated with this substrates' transport in yeast. The present study provides basic gene features and transcriptional information for the two new members of the AMT1 sub-family in P. betulaefolia and will aid in decoding the precise roles of AMTs in P. betulaefolia physiology.
authors.affiliation: Institute of Horticulture, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, No. 50 Zhongling Street, Nanjing, 210014, Jiangsu, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Institute of Horticulture, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, No. 50 Zhongling Street, Nanjing, 210014, Jiangsu, China.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Han
authors.affiliation: Institute of Horticulture, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, No. 50 Zhongling Street, Nanjing, 210014, Jiangsu, China. jaaschang@163.com.
authors.forename: You-Hong
authors.initials: YH
authors.lastname: Chang
authors.affiliation: Institute of Horticulture, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, No. 50 Zhongling Street, Nanjing, 210014, Jiangsu, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.affiliation: Institute of Horticulture, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, No. 50 Zhongling Street, Nanjing, 210014, Jiangsu, China.
authors.forename: Qing-Song
authors.initials: QS
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D064751:Ammonium Compounds / Q000378:metabolism*; D001483:Base Sequence; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D007700:Kinetics; D009584:Nitrogen / Q000494:pharmacology; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D017440:Photoperiod; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D031989:Pyrus / Q000187:drug effects / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D016415:Sequence Alignment; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D064751:Ammonium Compounds; D027682:Cation Transport Proteins; D018076:DNA, Complementary; D010940:Plant Proteins; D009584:Nitrogen
keywords: Ammonium transporter; Expression pattern; Functional complementation; Gene characterization; Pyrus betulaefolia