Cloning and Expression Analysis of Chlorogenic Acid Biosynthetic Gene Nt HQT1 from Nicotiana tabacum

Chlorogenic acid is the dominant polyphenol in leaf tobacco. Hydroxycinnamoyl-Co A quinate hydroxycinnamoyl transferase(HQT) is the key enzyme in the metabolic pathway of chlorogenic acid in plant. In order to study the function mechanism of HQT gene in the synthesis of chlorogenic acid in tobacco, a new HQT gene was cloned from Nicotiana tabacum by homologous cloning technology and named as Nt HQT1. The results of bioinformatics analysis and expression pattern analysis of genes treated by different hormones showed that Nt HQT1 c DNA was 1 305 bp in length and encoded 435 amino acids; it was a hydrophobic protein and located in cytoplasm, its secondary structure was mainly of helix and random coil. The expression of Nt HQT1 gene was obviously up-regulated by methyl jasmonate(Me JA),auxin(3-Indoleacetic acid, IAA), strigolactone(GR24), cytokinin(6-BA) and gibberellin acid(GA),while not obviously affected by abscisic acid(ABA). It suggested that Nt HQT1 might play an important role in the course of growth, development and disease resistance of tobacco.