title: LjMOT1, a high-affinity molybdate transporter from Lotus japonicus, is essential for molybdate uptake, but not for the delivery to nodules.
abstract: Molybdenum (Mo) is an essential nutrient for plants, and is required for nitrogenase activity of legumes. However, the pathways of Mo uptake from soils and then delivery to the nodules have not been characterized in legumes. In this study, we characterized a high-affinity Mo transporter (LjMOT1) from Lotus japonicus. Mo concentrations in an ethyl methanesulfonate-mutagenized line (ljmot1) decreased by 70-95% compared with wild-type (WT). By comparing the DNA sequences of four AtMOT1 homologs between mutant and WT lines, one point mutation was found in LjMOT1, which altered Trp292to a stop codon; no mutation was found in the other homologous genes. The phenotype of Mo concentrations in F2progeny from ljmot1 and WT crosses were associated with genotypes of LjMOT1. Introduction of endogenous LjMOT1 to ljmot1 restored Mo accumulation to approximately 60-70% of the WT. Yeast expressing LjMOT1 exhibited high Mo uptake activity, and the Kmwas 182 nm. LjMOT1 was expressed mainly in roots, and its expression was not affected by Mo supply or rhizobium inoculation. Although Mo accumulation in the nodules of ljmot1 was significantly lower than that of WT, it was still high enough for normal nodulation and nitrogenase activity, even for cotyledons-removed ljmot1 plants grown under low Mo conditions, in this case the plant growth was significantly inhibited by Mo deficiency. Our results suggest that LjMOT1 is an essential Mo transporter in L. japonicus for Mo uptake from the soil and growth, but is not for Mo delivery to the nodules.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.|Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Guilan
authors.identifier: http://orcid.org/0000-0002-2880-5017
authors.initials: G
authors.lastname: Duan
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Hakoyama
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kamiya
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Miwa
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.|National Agriculture and Food Research Organization (NARO) Institute of Crop Science, Ibaraki, 305-8518, Japan.
authors.forename: Fabien
authors.initials: F
authors.lastname: Lombardo
authors.affiliation: Kazusa DNA Research Institute, Kisarazu, Chiba, 292-0812, Japan.|Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai, 980-8577, Japan.
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.affiliation: Kazusa DNA Research Institute, Kisarazu, Chiba, 292-0812, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 010-8589, Japan.|Department of Environmental Science, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, 215123, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 010-8589, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 010-8589, Japan.|NARO Tohoku Agricultural Research Center, Arai, Fukushima, 960-2156, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Shinano
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D001692:Biological Transport / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D000070116:Lotus / Q000235:genetics / Q000378:metabolism*; D008982:Molybdenum / Q000378:metabolism*; D009586:Nitrogen Fixation / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D053204:Root Nodules, Plant / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; C044659:molybdate; D008982:Molybdenum
keywords: 
  Lotus japonicus
  ; molybdate transporter; molybdenum; nitrogen fixation; nodule