Tissue-specific expression of plant defensin genes PDF2.1 and PDF2.2 in Arabidopsis thaliana

Plant defensins are a family of cysteine-rich peptides, many members of which have been shown to exhibit antimicrobial activity. Sequence analysis of randomly expressed sequence tags has revealed the presence of five different plant defensin genes in Arabidopsis thaliana. Previous work has established the tissue-specific expression pattern of PDF1.1, PDF1.2 and PDF2.3. The present study reports on the expression patterns of PDF2.1 and PDF2.2. A compilation of all available data indicates that all Arabidopsis organs constitutively express one, and most of them two or more, plant defensin genes. Expression of PDF1.2 is upregulated upon infection of leaves by a fungal pathogen, while that of PDF2.2 is downregulated.