Induced gene expression of 1-aminocyclopropane-1-carboxylic acid (ACC oxidase) in pepper (Capsicum annuum L.) by arachidonic acid

Elicitation of pepper ( Capsicum annuum ) seedlings with arachidonic acid (AA) resulted in different defense responses. The transcriptional stimulation of the pepper phytoalexin biosynthesis related gene 5- epi -aristolochene synthase (PEAS) was demonstrated and a partial cDNA of the 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene (CA-ACCO) was also isolated. Ethylene accumulation was subsequent to the CA-ACCO gene expression in AA treated fruits. The level of CA-ACCO transcript was assayed in pepper seedlings after treatment with salicylic acid (SA), methyl jasmonate (MeJa), cellulase, and Phytophthora capsici infection, as well as in wounded and different ripening stage fruits. The CA-ACCO gene was strongly expressed under stress conditions but hardly detected in breaker stage pepper fruits in contrast with tomato ripening fruits. Southern blot analysis revealed 3–4 members of the CA-ACCO gene family according to similar genes as reported in other plants.