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 syn thase (PEAS) was demonstrated and a partial cDNA of the 1-aminocyclopropane -1-carboxylate (ACC) oxidase gene (CA-ACCO) was also isolated. Ethylene acc umulation was subsequent to the CA-ACCO gene expression in AA treated fruit s. The level of CA-ACCO transcript was assayed in pepper seedlings after tr eatment with salicylic acid (SA), methyl jasmonate (MeJa), cellulase, and P hytophthora capsici infection, as well as in wounded and different ripening stage fruits. The CA-ACCO gene was strongly expressed under stress conditi ons but hardly detected in breaker stage pepper fruits in contrast with tom ato ripening fruits. Southern blot analysis revealed 3-4 members of the CA- ACCO gene family according to similar genes as reported in other plants. (C ) 1999 Elsevier Science Ireland Ltd. All rights reserved.