Research on genes associated with female flower development of Phellodendron amurense Rupr. based on transcriptome data

Abstract: Phellodendron amurense Rupr., a species of Rutaceae, is a national protected and valuable medicinal plant. It is generally considered to be dioecious. With the discovery of monoecious P. amurense, the phenomenon that its sex development is regulated by epigenetics has been revealed, but the way epigenetics affects the sex differentiation of P. amurense is still unclear. In this study, we investigated the effect of DNA methylation on sexual development. The young inflorescences of male plants were treated with the demethylation agent 5-azaC and the induced female flowers were obtained. The morphological function and transcriptome levels of the induced female flowers were close to those of normally developed plants. Genes associated with the development of female flowers were studied by comparing the differences in transcriptome level between the male and female flowers. Referring to sex-related genes reported in other plants, 188 candidate genes related to the development of female flowers were obtained, including sex-regulating genes, genes related to the formation and development of sexual organs, genes related to biochemical pathways, and hormone-related genes. RPP0W, PAL3, MCM2, MCM6, SUP, PIN1, ANT, AIL6, AGL11, SEUSS, SRS5 and ESR2 were preliminarily considered to be the key genes for female flower development. This study demonstrated that epigenetics was involved in the sex regulation of P. amurense, with DNA methylation as one of its regulatory modes. Moreover, some candidate genes related to the sexual differentiation of P. amurense were obtained through analysis. The results are of great significance for further exploring the mechanism of sex differentiation of P. amurense and studying of sex differentiation of plants.