Raw Transcriptome sequence reads of male and female floral buds of the persimmons (Diospyros kaki Thunb.)

The lack of male flowers strongly restricts controlled pollination in persimmons (Diospyros kaki Thunb.). Thus, there is great interest in persimmon sex determination and differentiation, not only in terms of basic science but also from the perspective of breeding, which includes the cultivation of male flowers and the promotion of controlled pollination. Although the OGI / MeGI system was reported essential in the sex determination in persimmons, the detailed regulatory mechanism on sex differentiation still needs further investigation. In this study, RNA-Sequencing and comparative analysis between male and female floral buds collected from a same 'Zenjimaru' tree (Diospyros kaki) were conducted to gain insights into gene expression profiles. 154741 unigenes were obtained by Illumina Hiseq transcriptome sequencing, of which a total of 59570 (38.49%) were annotated with the basic local alignment search tool (BlAST) against seven databases. 1228 genes expressed differently between the male and female floral buds. According to the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and BLAST analysis, 25 differently expressed genes, with the function of phytohormone biosynthesis and signaling transduction, development of floral organs, transcription regulation, and programmed cell death (PCD) et al., were screened out as crucial genes for the regulation of sex differentiation. Among the 25 genes, 15 were up-regulated in the male floral buds compared with the female floral buds, while the other 10 were down-regulated. Subsequently, the expression patterns of six crucial genes respectively homologous to MeGI, GA20OX2, ACO, IAA32, Beta-amyrin 28-oxidase-like and HEC1 were determined in the male and female floral buds during development with the use of real-time quantitative PCR (RT-qPCR). The results revealed that the genes homologous to IAA32, Beta-amyrin 28-oxidase-like and HEC1 showed male promotion effects from early June to the next late March. The gene homologous to GA20OX2 may stimulate the development of male floral buds during April. In contrast, the genes homologous to MeGI and ACO showed female promotion effects from early April to early May. The transcriptome data provide comprehensive gene profiles for sex differentiation in Diospyros kaki, and give new directions and information for further studies in this field.