Characterisation and functional analysis of two barley caleosins expressed during barley caryopsis development

Planta. 2005 Jun;221(4):513-22. doi: 10.1007/s00425-004-1465-5. Epub 2005 Feb 9.

Abstract

Two full-length cDNA sequences homologous to caleosin, a seed-storage oil-body protein from sesame, were identified from a series of barley grain development cDNA libraries and further characterised. The cDNAs, subsequently termed HvClo1 and HvClo2, encode proteins of 34 kDa and 28 kDa, respectively. Real-time RT-PCR indicated that HvClo1 is expressed abundantly during the later stages of embryogenesis and is seed-specific, accumulating in the scutellum of mature embryos. HvClo2 is expressed mainly in the endosperm tissues of the developing grain. We show that HvClo1 and HvClo2 are paralogs that co-segregate on barley chromosome 2HL. Transient expression of HvClo1 in lipid storage and non-storage cells of barley using biolistic particle bombardment indicates that caleosins have different subcellular locations from the structural oil-body protein oleosin, and by inference participate in different sorting pathways. We observe that caleosin sorts via small vesicles, suggesting a likely association with lipid trafficking, membrane expansion and oil-body biogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium-Binding Proteins / biosynthesis*
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant
  • Hordeum / growth & development
  • Hordeum / metabolism*
  • Lipid Metabolism
  • Plant Proteins / biosynthesis*
  • Seeds / metabolism

Substances

  • Calcium-Binding Proteins
  • Plant Proteins
  • caleosin protein, Sesamum indicum