Phylogenetic analysis and expression profiling of Nuclear Factor-Y gene family in Dendrobium catenatum Lindl. (Orchidaceae)

Abstract

Nuclear factor-Y (NF-Y) are transcription factors that play vital role in various developmental processes such as flowering, embryogenesis, root formation, nodulation and stress tolerance. In the present study, 27 NF-Y genes were identified in Dendrobium catenatum which were grouped into three sub-families: DcNF-YA (5), DcNF-YB (10) and DcNF-YC (12), on the basis of presence of specific conserved domains. The phylogenetic relationship between DcNF-Y protein sequences with their orthologs in Vanilla planifolia and Arabidopsis thaliana confirmed the classification of these proteins into the specified three groups. Physico-chemical characterization reported a wide range in the protein length (111 to 433 amino acids), with DcNF-YAs being longer than the others. Strong interaction between most of the DcNF-Y proteins suggests towards the formation of complexes which might be playing a role in different developmental processes. Gene architectural studies predicted the presence of multiple (3–6) introns in DcNF-YA in contrast with the intron-less status of majority of DcNF-YB and DcNF-YC genes. The abundance of stress related cis-regulatory elements in the promoter regions of DcNF-Y genes indicate the potential of these genes in stress tolerance. Additionally, variable expression of these genes in diverse tissues point towards their widespread role in growth and development. This work can act as a harbinger for functional characterization of NF-Y genes with a view for genetic improvement in Dendrobium catenatum Lindl.