||Ethylene, a plant hormone, plays an essential role in many aspects about plant development, growth, ripening, and senescence. In addition, it also regulates several responses when plants suffer stress from drought, flood, herbivore bites, wound, etc. ACC synthase and ACC oxidase belong to two multigene families. In this study, PCR (polymerase chain reaction) and RACE (rapid amplification of cDNA ends) methods were used to amplify the ACC oxidase sequences in Cattleya bicolor orchid flower. The results show that there exists differences in the 3’-UTR (untranslated region) of orchid gene sequences. Compare the ACC oxidase sequences, including the cDNA ORF (open reading frame) sequences and the amino acid sequences, of several different species, the sequence similarity among the three Laeliinae orchids, namely C.bicolor, C. intermedia, and Laelia anceps, is the highest. The similarity of cDNA ORF sequences and amino acid sequences between orchids and the other plants, such as rice, apple and torenia, is comparatively lower. It was proposed that the protein located in cytoplasma (or in mitochondrial matrix space), agrees with the result from analysis of amino acid hydrophilicity prediction.|
The ultimate goal of this study is to postpone the flower senescence by the way of plant transfection. In the present findings, it only deals with the cloning and analysis of the ACC oxidase genes in C. bicolor.