Objective AP3 plays an important role in the development of floral organs in many plants, However, there are no relevant reports on AP3 gene and its function in pineapple. This study can provide a theoretical basis for the functional identification of AcMADS41 in pineapple flower development.

Method An AP3 gene, AcMADS41, which may be involved in flower development, was cloned from pineapple flower bud. The physicochemical properties, protein domains, evolutionary relationships and cis-acting elements etc. were predicted by bioinformatics analysis.

Result The full-length DNA sequence of this gene was 5 098 bp, with a coding region of 458 bp, encoding 155 amino acids. It contained the MADS-BOX domain and K-BOX domain unique to the MIKC subfamily of the MADS-box family. Phylogenetic analysis showed that AcMADS41 clustered with date palm(Phoenix dactylifera)and oil palm(Elaeis guineensis), and it was speculated that AcMADS41 would play the same important function as AP3 in flower bud differentiation. Genomic data analysis showed that AcMADS41 was mainly expressed in flowers. RNA-Seq analysis showed that AcMADS41 was not expressed in early anthesis, but was highly expressed in late anthesis, and was mainly expressed in petals, stamens and styles. The relative expression of ACMADS41 gene was the highest in styles, which may be a key gene in style development.

Conclusion The results provides a theoretical basis for the identification of the function of AcMADS41 in pineapple flower development, which is of great significance to further explore the molecular mechanism of flower formation in pineapple.