MADS-box genes are a family of regulatory transcription factors found in all eukaryotes and play a crucial role in controlling various aspects of plant growth and development, including flowering, fruit ripening, and seed formation. Plantago ovata is a medicinal plant, and its draft genome has been recently published. Here we focused on MADS-box gene family and identified 126 MADSbox genes in P. ovata genome. We further analyzed their phylogenetic relationships, gene structures, motif composition, promoter characteristics and expression patterns. Based on the phylogenetic relationship, P. ovata contain 57 MIKC type MADS-box genes which is significantly higher than the number of MIKC-type genes in Arabidopsis. Furthermore, our finding indicates that tandem duplication has played a key role in the expansion of type I genes. Most type I genes were single exon genes. The analysis of cis-regulatory elements showed that PoMADS-box family generally respond to light and further could play a role in abiotic stress and hormone responses. Based on publicly-available RNA-seq data, Most of the identified MADS-box genes, expressed in at least two out of eight (4 time-intervals post anthesis and two genotypes) treatments. The expression heatmap of the 94 remaining genes indicates that three highly, moderately and low expressed groups of MADS-box genes exist. In conclusion, this study may facilitate further functional studies of MADS-box genes in P. ovata.
