| Class III peroxidases have been identified as secreted proteins involved in plant defense, auxin metabolism, cell wall modification, and regulation of reactive oxygen species. Transcriptome analysis of Arabidopsis has identified many class III peroxidases that respond to aluminum stress. The large number and versatile function of peroxidases make functional characterization of individual peroxidases a challenging task. However, the use of promoter::GUS reporter fusions can help to elucidate the expression pattern of individual peroxidases. To investigate the expression of PER22 and PER73 under aluminum stress in Arabidopsis, single-copy, homozygous, transgenic plants harbouring promoter::GUS reporter fusions were generated through self-pollination and southern blot analyses. Histochemical GUS staining of transgenic lines revealed trichome-specific and vascular-specific expression patterns for PER22 and PER73, respectively. The temporal and spatial expression of PER22 and PER73 suggest that they might be involved in pathogen defense and/or lignification. Further experiments will help define these peroxidase functions under aluminum stress. |
