title: Molecular cloning and expression analysis of an 1-aminocyclopropane-1-carboxylate synthase gene from Oncidium Gower Ramsey.
abstract: 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) is a rate-limiting enzyme in the biosynthesis of ethylene which regulates many aspects of the plant development and responses to biotic and abiotic stresses. In this study, a full-length cDNA of ACC synthase, OnACS2, was cloned from the senescing flower of Oncidium Gower Ramsey by RACE. The full-length cDNA of OnACS2 (GenBank accession no. JQ822087) was 1557 bp in length with an open reading frame (ORF) of 1308 bp encoding for a protein of 435 amino acid residues. The predicted OnACS2 protein had a molecular mass of 49.1 kDa with pI value of 7.51. Phylogenetic analysis indicated its evolutionary relationships with corresponding orthologous sequences in orchids, Hosta ventricosa and monocots. Real-time PCR assay demonstrated that OnACS2 was constitutively expressed in all tested organs with the highest transcript level in the gynandria. Differential expression pattern of OnACS2 gene correlated to the ethylene production and the subsequent occurrence of senescent symptoms in flower suggested that OnACS2 probably played an important role in the initiation of flower senescence.
authors.affiliation: Key Laboratory of Protection and Development Utilization of Tropical Crop Germplasm Resources (Hainan University), Ministry of Education, College of Agronomy, Hainan University, Haikou, Hainan Province, 570228, China.
authors.forename: Le-Song
authors.initials: LS
authors.lastname: Shi
authors.affiliation: Key Laboratory of Protection and Development Utilization of Tropical Crop Germplasm Resources (Hainan University), Ministry of Education, College of Agronomy, Hainan University, Haikou, Hainan Province, 570228, China. Electronic address: liu3305602@163.com.
authors.forename: Jin-Ping
authors.initials: JP
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D016922:Cellular Senescence / Q000502:physiology; D003001:Cloning, Molecular / Q000379:methods; D004789:Enzyme Activation; D004926:Escherichia coli / Q000166:cytology / Q000502:physiology*; D005030:Ethylenes / Q000096:biosynthesis*; D035264:Flowers / Q000201:enzymology / Q000235:genetics; D008190:Lyases / Q000737:chemistry* / Q000502:physiology*; D008969:Molecular Sequence Data; D029595:Orchidaceae / Q000201:enzymology* / Q000235:genetics*; D010937:Plant Growth Regulators / Q000096:biosynthesis
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase
keywords: ACC synthase; Ethylene biosynthesis; Expression analysis; Flower senescence; Gene cloning; Oncidium Gower Ramsey