ABCG9, ABCG11 and ABCG14 ABC transporters are required for vascular development in Arabidopsis

Plant J. 2013 Dec;76(5):811-24. doi: 10.1111/tpj.12334.

Abstract

In order to obtain insights into the regulatory pathways controlling phloem development, we characterized three genes encoding membrane proteins from the G sub-family of ABC transporters (ABCG9, ABCG11 and ABCG14), whose expression in the phloem has been confirmed. Mutations in the genes encoding these dimerizing 'half transporters' are semi-dominant and result in vascular patterning defects in cotyledons and the floral stem. Co-immunoprecipitation and bimolecular fluorescence complementation experiments demonstrated that these proteins dimerize, either by flexible pairing (ABCG11 and ABCG9) or by forming strict heterodimers (ABCG14). In addition, metabolome analyses and measurement of sterol ester contents in the mutants suggested that ABCG9, ABCG11 and ABCG14 are involved in lipid/sterol homeostasis regulation. Our results show that these three ABCG genes are required for proper vascular development in Arabidopsis thaliana.

Keywords: ABC transporters; ABCG dimer; Arabidopsis thaliana; lipid/sterol homeostasis; vascular development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily G
  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism*
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cotyledon / genetics
  • Cotyledon / growth & development
  • Homeostasis
  • Metabolome
  • Mutation
  • Phloem / genetics
  • Phloem / growth & development*
  • Phytosterols / chemistry
  • Plant Stems / genetics
  • Plant Stems / growth & development
  • Protein Multimerization

Substances

  • ABCG11 protein, Arabidopsis
  • ABCG14 protein, Arabidopsis
  • ABCG9 protein, Arabidopsis
  • ATP Binding Cassette Transporter, Subfamily G
  • ATP-Binding Cassette Transporters
  • Arabidopsis Proteins
  • Phytosterols