Temporal and spatial expression analysis of PRGL in Gerbera hybrida.

GASA-like genes form multigene families in diverse plant species and encode the proteins with a unique cysteine-rich domain (GASA domain). In our previously work, we cloned a GASA-like gene PRGL (Proline-rich GASA-like) from gerbera. Here we report the expression profiles of PRGL and the subcellular localization of PRGL protein. Multiple sequence alignment of the GASA domains indicates that PRGL shows the highest homology to AtPRGL (73.3% of amino acid identity) from Arabidopsis. Phylogenic analysis based on the full amino acid sequences indicates that PRGL and AtPRGL belong to a novel subfamily of GASA proteins. Northern blot assay showed that PRGL is highly expressed in young flower, young leaf and young root, whereas hardly detected when these organs became mature. Furthermore, in young inflorescence, PRGL transcript accumulation only occurred in the fast elongation organs such as scape, ray floret petal and disc floret petal. Western blot and immunolocalization assay revealed that PRGL protein is located in cell wall and high level accumulation of PRGL was found to correlate with the fast organ elongation in scape. Our results suggest that PRGL participates in the regulation of cell elongation during the development of Gerbera hybrida plant.