Isolation and functional analysis of a pepper lipid transfer protein III (CALTPIII) gene promoter during signaling to pathogen, abiotic and environmental stresses

The promoter fragment of 1065 bp upstream from the translation initiation site of the CALTPIII gene encoding a basic lipid transfer protein was isolated from the genomic DNA of Capsicum annuum. Some putative cis-acting elements, including an ERE-box, a W-box, and MYB-core elements were found in the promoter region of the CALTPIII gene. In Agrobacterium-mediated transient expression assay, strong activation of the CALTPIII full promoter region (1065 bp long) occurred in tobacco leaves after infection with Pseudomonas syringae pv. tabaci, and treatments with ethylene, salicylic acid, methyl jasmonate and H2O2. However, the full promoter did not respond to abscisic acid while previous studies have shown that the CALTPIII mRNA is indeed induced by ABA. Pathogen and ethylene responses were mostly affected by the deletion between −830 and −422 bp. Salicylic acid response was lost in any deleted construct. A fine analysis showed that the crucial elements for pathogen response are located between −626 and −552 bp.