Identification and functional expression of the pepper pathogen-induced gene, CAPIP2, involved in disease resistance and drought and salt stress tolerance.

A novel pathogen-induced gene, designated CAPIP2, was isolated from pepper leaves infected with Xanthomonas campestris pv. vesicatoria. CAPIP2:GFP fusion proteins were primarily localized in the cytoplasm. The CAPIP2 transcripts were constitutively expressed in the pepper leaves, flowers, and fruits, but were not detected in the stems and roots. CAPIP2 gene expression was induced strongly in the pepper leaves during pathogen infection, and also after exposure to abiotic elicitors and environmental stresses. Ectopic CAPIP2 expression in Arabidopsis was accompanied by the expression of Arabidopsis PR-1 and PDF1.2 genes. Overexpression of the CAPIP2 gene in Arabidopsis transgenic plants conferred enhanced resistance to Pseudomonas syringae pv. tomato DC3000. The CAPIP2 transgenic Arabidopsis also manifested increased tolerance to high salt, drought and oxidative stress during seed germination and seedling state. These results suggest that pepper CAPIP2 gene may function as a defense-related gene against both biotic and abiotic stresses.