Poster: Respiratory Pathways

Abs # 267: Promoter analysis of alternative oxidase from Catharanthus roseus

Presenter:	Kiyota, Seiichiro , skiyota@nias.affrc.go.jp
Authors	Kiyota, Seiichiro  (A)   Yazaki, Yoshiaki  (A)
Affiliations:	(A): Natinal Institute of Agrobiological Sciences

Alternative oxidase (AOX) is the terminal oxidase of cyanide-resistance respiration. We have found that treatments of Catharanthus roseus (C. roseus) cells with salicylic acid, propionic acid and sodium vanadate induced immediate cytoplasmic acidification and successive AOX expression. However, induction mechanism for AOX is not fully understood.
We isolated genomic clone (12kb) of AOX from C. roseus. The AOX gene had 3 introns, which is a common feature of plant AOXs. DNA blotting revealed that AOX was coded as a single gene in C. roseus. This is in contrast to other plants such as rice, Arabidopsis and potato, which have several AOX genes with differential expression profiles. The transcription initiation site, determined by oligo-CAP method, was 122bps upstream from the translation starting point.
AOX promoter-candidates had various lengths (2.31-0.48kb upward from the transcription starting site) were ligated to the GUS reporter gene of the pBI221 vector. All constructs showed promoter activity in transiently transformed C. roseus cells by particle bombardment. The longest one (2.31kb) showed the strongest activity. We will also report analysis of stable transformants to indentify cis elements involved in AOX induction.