Identification and characterization of MADS box gene family in pigeonpea for their role during floral transition.

Unlabelled: MADS box genes are class of transcription factors involved in various physiological and developmental processes in plants. To understand their role in floral transition-related pathways, a genome-wide identification was done in , identifying 102 members which were classified into two different groups based on their gene structure. The status of all these genes was further analyzed in three wild species i.e. , and which revealed absence of 31-34 MADS box genes in them hinting towards their role in domestication and evolution. We could locate only a single copy of both FLOWERING LOCUS C () and SHORT VEGETATIVE PHASE () genes, while three paralogs of SUPPRESSOR OF ACTIVATION OF CONSTANS 1 () were found in genome. One of those paralogs i.e. CcMADS1.5 was found to be missing in all three wild relatives, also forming separate clade in phylogeny. This gene was also lacking the characteristic MADS box domain in it. Expression profiling of major MADS box genes involved in flowering was done in different tissues viz shoot apical meristem, vegetative leaf, reproductive meristem, and reproductive bud. Gene-based time tree of and gene dictates their divergence from before 71 and 23 million year ago (mya), respectively. This study provides valuable insights into the functional characteristics, expression pattern, and evolution of MADS box proteins in grain legumes with emphasis on , which may help in further characterizing these genes.

Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-020-02605-7.