De novo transcriptome assembly reveals characteristics of flower sex determination of Excoecaria agallocha

Abstract

Key message: MADS-box genes family may play important roles in the flower sex determination in Excoecaria agallocha. A total of 73 MADS-box genes were identified in E. agallocha. De novo transcriptome assembly analysis suggested that AP1/FUL, AP3/PI, AGL104, and SOC1 plays potential roles in E. agallocha flower sex determination. Context: Excoecaria agallocha is a dioecious species containing both male and female individuals producing unisexual flowers. The underlying mechanisms regulating inflorescence differentiation in these species remains poorly understood. Aims: Flower development influences reproduction and breeding in E.agallocha, which contributes to ecological restoration in the intertidal zone. Methods: We performed de novo transcriptome assembly analysis on male and female flowers and leaves from E. agallocha. Results: We identified a total of 73 MADS-box genes in the E. agallocha genome, which we grouped into five distinct classes (MIKCc, Mα, Mβ, Mγ, MIKC*) after phylogenetic comparisons with J. curcas homologs. We analyzed expression profiles and suggested AP1/FUL, AP3/PI, AGL104, and SOC1 as candidate regulators of sex determination. In addition, several EaMADS genes were significantly upregulated in flowers compared to leaves. Conclusion: Our study represents the first detailed, comprehensive evaluation of the regulation of MADS-box genes associated with sex determination in E. agallocha. The assembled transcriptomic profiles increase the genetic information available for this species and constitute an important contribution to functional studies of inflorescence genes. In turn, this will help exploring the molecular mechanisms underlying the evolution of E. agallocha.