CLONING AND CHARACTERIZATION OF ETHYLENE RECEPTOR GENE FROM DENDROBIUM SONIA 'BOM 17'

Full length ethylene receptor gene from flower bud of Dendrobium Sonia 'BOM 17', Den-ERS1, was cloned and fully sequenced using reverse transcriptase-polymerase chain reaction (RT-PCR) and 3' and 5' rapid amplification of cDNA ends (3' and 5' RACE) techniques. Den-ERS1 is 1,866 bp in length, encodes a 69.8 kDa polypeptide of 621 amino acids. The sequence shares highly conserved between Orchidaceae counterparts, Phalaenopsis sp. 'KC Butterfly', with 92 and 91% identical at nucleotide and amino acid levels, respectively. The deduced polypeptide contains three transmembrane halices and a conserved signal transduction histidine kinase domain that is a characteristic to ethylene receptors. RT-PCR analysis has shown that Den-ERS1 transcripts could be amplified from the total RNA of unopened flower buds at specific stage and mature leaves, but not from RNA of opening flower buds, full bloom flowers, immature leaves, young shoot, pseudobulbs or roots. Southern blot analysis indicated that Den-ERS1 might exist as a single copy in the genome.