Genome-Wide Identification of MIKCc-Type MADS-Box Family Gene and Floral Organ Transcriptome Characterization in Ma Bamboo (Dendrocalamus latiflorus Munro)

Most bamboos die after flowering, and the molecular mechanisms responsible for flowering is poorly understood. The MIKCc-type MADS-box family gene is involved in the flowering process. To explore the mechanism of the MIKCc-type MADS-box gene and phytohormone regulation in the flowering of Dendrocalamus latiflorus Munro (D. latiflorus), characterized by extremely rapid growth and widely cultivated woody bamboo, we initially did a genome-wide analysis of the MIKCc-type MADS-box gene in D. latiflorus. In the meantime, transcriptome analysis was performed using the floral organs. A total of 170 MIKCc-Type MADS-Box genes were identified and divided into 15 categories. The cis-acting element analysis in promoters regions revealed that MIKC-type MADS-box family genes were associated with hormones, including auxin, abscisic acid (ABA), gibberellin (GA) and jasmonic acid (JA), which was found at 79, 476, 96, 486 sites and cover 61, 103, 73, 128 genes. Genome synteny analysis showed subgenome AA and BB were better than CC and obtained 49, 40, 39 synteny genes compared with Oryza sativa (O. sativa). In transcriptome analysis of floral organs, the enriched pathway from DEGs included circadian, vernalization and gibberellin pathways associated with the flowering process. We found that the jasmonic acid synthesis gene is highly expressed in the pistil, which may be the cause of Ma bamboo pollen abortion. The expression profile showed that most MIKC-type MADS-box genes exhibited high expression in flower organs. The consequences of this study will provide insight into the irregular flowering and low pollen counts of Ma bamboo.