Molecular characterization and expression analysis of MADS box gene family in selected orchid species

Abstract

Orchids have an immense commercial potential because of their beautiful, variously colored and long-lasting flowers. The MADS-box gene family encodes the transcription factors that partake in the various developmental processes, especially florigenesis. In present study, a total of 48, 30 and 28 MADS-box members had identified in the Phalaenopsis equestris, Vanilla planifolia and Vanda cristata, respectively. The phylogenetic analysis of type I and type II MADS-box proteins segregated these proteins in various subclasses. Protein characterization, duplication events and their evolutionary analyses were also studied. Expression profiling of MADS-box genes in various developmental tissues depicted their roles in flower development. Moreover, the semi-quantitative RT-PCR and qRT-PCR approaches validated their participation in reproductive organ development. Furthermore, co-expression studies of PeMADS and VcMADS genes provides the clue about their interaction with various development and stress responsive genes. Thereafter, the VcMADS21 gene of Vanda cristata was cloned in the pDrive cloning vector. The present study helps in the better understanding of the MADS-box gene family in these three studied plants. Ultimately this paves the path for functional characterization of selected MADS-box genes in planta. newline