Identification, expression analyses of APETALA1 gene homologs in Bambusa tulda and heterologous validation of BtMADS14 in Arabidopsis thaliana.

Bamboos belong to the grass family Poaceae, sub-family Bambusoideae and possess many interesting developmental features including a long vegetative period before flowering. Previously, transcriptome based analyses have identified differentially expressed transcripts in flowering and vegetative tissues to predict gene clusters of functional relevance. In contrast, limited studies were conducted to characterize individual genes to decipher their precise role to induce flowering. This was primarily due to the unavailability of sufficient genomic resources, which has lately been overcome by the release of additional bamboo genomes. In this study, the APETALA1 gene homologs (MADS14, MADS15, MADS18 and MADS20) have been identified from five sequenced bamboo species (Bonia amplexicaulis, Guadua angustifolia, Raddia guianensis, Olyra latifolia, Phyllostachys edulis). In addition, APETALA1 homologs from a tropical bamboo (Bambusa tulda) have been PCR amplified, sequenced and included in the analyses to widen spectrum of sampling. Assessment of their phylogenetic and syntenic relationship with related Poaceae neighbours revealed closer relationship between MADS14 and MADS15 members than MADS18 and MADS20. Transcriptional expression patterns of B. tulda BtMADS14, BtMADS15, BtMADS18 and BtMADS20 in vegetative and floral tissues indicated a possible role of BtMADS14 and BtMADS15 in flower induction and differentiation, while BtMADS18 might be associated with seed development. Total 24 proteins were predicted to interact with the Phyllostachys edulis homolog of BtMADS14 protein and 8 of them were members of the MADS-box family. The p35S::BtMADS14 overexpressing Arabidopsis plants flowered 8-10 days earlier than the wild type plants suggesting its possible involvement in the floral induction of B. tulda. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-025-01569-3.