title: Phloem-localizing sulfate transporter, Sultr1;3, mediates re-distribution of sulfur from source to sink organs in Arabidopsis.
abstract: For the effective recycling of nutrients, vascular plants transport pooled inorganic ions and metabolites through the sieve tube. A novel sulfate transporter gene, Sultr1;3, was identified as an essential member contributing to this process for redistribution of sulfur source in Arabidopsis. Sultr1;3 belonged to the family of high-affinity sulfate transporters, and was able to complement the yeast sulfate transporter mutant. The fusion protein of Sultr1;3 and green fluorescent protein was expressed by the Sultr1;3 promoter in transgenic plants, which revealed phloem-specific expression of Sultr1;3 in Arabidopsis. Sultr1;3-green fluorescent protein was found in the sieve element-companion cell complexes of the phloem in cotyledons and roots. Limitation of external sulfate caused accumulation of Sultr1;3 mRNA both in leaves and roots. Movement of (35)S-labeled sulfate from cotyledons to the sink organs was restricted in the T-DNA insertion mutant of Sultr1;3. These results provide evidence that Sultr1;3 transporter plays an important role in loading of sulfate to the sieve tube, initiating the source-to-sink translocation of sulfur nutrient in Arabidopsis.
authors.affiliation: RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Yoshimoto
authors.forename: Eri
authors.initials: E
authors.lastname: Inoue
authors.forename: Kazuki
authors.initials: K
authors.lastname: Saito
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamaya
authors.forename: Hideki
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000595:Amino Acid Sequence; D027321:Anion Transport Proteins; D017360:Arabidopsis / Q000033:anatomy & histology / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D001693:Biological Transport, Active / Q000502:physiology; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D018514:Plant Structures / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D013455:Sulfur / Q000378:metabolism*
chemical_list: D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C476107:Sultr1;3 protein, Arabidopsis; D013455:Sulfur