Molecular cloning and expression of 1-deoxy-D-xylulose-5-phosphate synthase and 1-deoxy-D-xylulose-5-phosphate reductoisomerase in Dendrobium officinale

1-Deoxy-d-xylulose-5-phosphate synthase (DXS) and 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) are the important rate-determining procedure in the plastidial methylerythritol phosphate pathway. In the present experiment, both of DXS and DXR genes were isolated from Dendrobium officinale protocorms. The two full-length cDNA, designated as DoDXS and DoDXR, were predicted to encode the polypeptides of 727 and 470 amino acid residues, respectively. DoDXS and DoDXR were differentially expressed in roots, stems, leaves and protocorms, with higher transcript level in roots and stems compared with other organs. For further analysis of the regulation of both genes expression, abscisic acid (ABA), methyl jasmonate (MeJA), salicylic acid (SA) and brassinolide (BR) were applied to treat the protocorms. As a result, transcript levels of DoDXS and DoDXR were induced by ABA, MeJA and SA, whereas their transcript levels were not regulated by BR.