title: Amino acid carriers of Ricinus communis expressed during seedling development: molecular cloning and expression analysis of two putative amino acid transporters, RcAAP1 and RcAAP2.
abstract: This study reports on the isolation of two putative amino acid carrier cDNAs, RcAAP1 and RcAAP2, from Ricinus communis. Northern analysis shows that RcAAP1 and RcAAP2 are expressed abundantly in the cotyledon and root tissues of developing seedlings and at lower levels in the endosperm and hypocotyl. In the mature plant low expression was observed in the source and sink leaves. We have further characterized the expression of RcAAP1 in Ricinus roots by in situ hybridization. The transcripts are localized in many cell types of the root tip region, including the epidermal and cortical cells, but the highest expression was observed in the cells of the stele situated adjacent to the xylem poles. This is the first report describing the cellular expression of an amino acid transporter in roots, and the results are discussed in relation to the physiological role of this transporter.
authors.affiliation: School of Biological Sciences, University of Southampton, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Bick
authors.forename: A
authors.initials: A
authors.lastname: Neelam
authors.forename: J L
authors.initials: JL
authors.lastname: Hall
authors.forename: L E
authors.initials: LE
authors.lastname: Williams
mesh_terms: D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems; D002367:Ricinus communis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D003001:Cloning, Molecular; D018548:Cotyledon; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017403:In Situ Hybridization; D026901:Membrane Transport Proteins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D018517:Plant Roots; D010947:Plants, Toxic; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D026905:Amino Acid Transport Systems; D026901:Membrane Transport Proteins; D012333:RNA, Messenger