Abstract: The thioredoxin-like 2 gene (DoTrxL2) in Dendrobium officinale Kimura et Migo was cloned by RACE and nest PCR technologies. The full length of DoTrxL2 contained an open reading frame (ORF) of 639 bp encoding 213 amino acid residues, whose product contained a conserved CXXC domain. Phylogenetic analysis showed that the DoTrxL2 had the closest relationship with monocotyledons, such as Phalaenopsis equestris and Asparagus officinalis. qRT-PCR analysis showed that the expression levels of DoTrxL2 were significantly varied in different developmental stages of protocorm and different tissues, which indicated that the DoTrxL2 plays an important role in the development of protocorm and the morphogical establishment of tissues in plant.

Key words: Dendrobium officinale Kimura et Migo, thioredoxin 2 gene, RACE, qRT-PCR