Cloning and Expression of Mannose-1-phosphate Guanyltransferase Gene in Anoectochilus roxburghii

  Objective  Cloning and expression of mannose-1-phosphate guanyltransferase (GMP) gene that regulates the polysaccharide synthesis in Anoectochilus roxburghii were studied.

  Method  ArGMP cDNA and genome sequences were cloned, and bioinformatics analyzed using online software. Gene expression pattern was then determined by qRT-PCR.

  Result  The ORF of ArGMP was 1 086 bp encoded 361 amino acids with a length of 1 760 bp that contained 3 introns. It has an accession number of OQ030271 in GenBank. A stable hydrophilic protein free of a transmembrane structure, it was closely related to those of Dendrobium officinale, Apostasia shenzhenica, and Phalaenopsis equestris. Expressed differently in different tissues, the highest level was found in the flowers. The expression varied under different temperatures that peaked at 25 ℃, decreased significantly after 3 h at 35 ℃, and was severely inhibited beyond that. However, it was not affected by the stress exerted by NaCl in different concentrations.

  Conclusion  The cDNA and sequence of GMP gene from A. roburghii were successfully cloned to display a tissue-specific expression pattern that could be significantly affected by temperature but not salt stress.