Background: Dendrobium catenatum, which grows on the semi humid rocks in the mountains, has been at the top of the "Nine Immortals of China" since ancient times. It is a kind of yin tonic medicine and its main active component is polysaccharide. Cellulose synthase-like D(CslD) genes were predicted to catalyse the biosynthesis of 1,4-β-d-glycan backbone of hemicelluloses, which plays fundamental roles in plant development.
Results: To investigate the role of CslD in the development of Dendrobium catenatum, eight CslD genes (DcCslD1,2a,2b,3a,3b,4a,4b,5) were identified. The results of protein prediction and analysis showed that CslD2a/2b/4a/4b proteins were acidic proteins, the rest were basic proteins; Leu, Ser, Ala, Gly, Arg, Pro and Asp were the main amino acids. All the proteins had obvious hydrophobic or hydrophilic regions, and had transmembrane structure. The main elements of protein secondary structure were α-helix, random coil and extended chain. Phylogenetic analysis revealed that the DcCslD family could be divided into Ⅰ, Ⅱ, Ⅲ and Ⅳ groups. DcCslD proteins had typical Cellulose synthase domain and similar protein structures to the CslDs of other plants. Their promoter regions contain cis regulatory elements related to stress and hormone. The results of qRT-PCR showed that the identified DcCslDs were differentially expressed in roots, stems and leaves. Most of them hightly expressed in stems and leaves. What’s more, the environmental stress1es examination showed that the expressions of DcCslD5 were closely associated with drought-recovery treatment, the expression of DcCslD1, DcCslD2a, DcCslD2b, DcCslD3a, and DcCslD5 were significantly influenced by low temperature.
Conclusions: This study systematically analyzed the sequence characteristics of CslD protein of D. catenatum, which can provide reference for further study on the function of CslD protein in polysaccharide metabolism of D. catenatum.