Screening and identification of miRNAs related to sexual differentiation of strobili in Ginkgo biloba by integration analysis of small RNA, RNA, and degradome sequencing

Abstract

Background: Ginkgo biloba, a typical dioecious plant, is a traditional medicinal plant widely planted. However, it has a long juvenile period, which severely affected the breeding and cultivation of superior ginkgo varieties. Results: In order to clarify the complex mechanism of sexual differentiation in G. biloba strobili. Here, a total of 3293 miRNAs were identified in buds and strobili of G. biloba, including 1085 known miRNAs and 2208 novel miRNAs using the three sequencing approaches of transcriptome, small RNA, and degradome. Comparative transcriptome analysis screened 4346 and 7087 differentially expressed genes (DEGs) in male buds (MB) vs female buds (FB) and microstrobilus (MS) vs ovulate strobilus (OS), respectively. A total of 6032 target genes were predicted for differentially expressed miRNA. The combined analysis of both small RNA and transcriptome datasets identified 51 miRNA-mRNA interaction pairs that may be involved in the process of G. biloba strobili sexual differentiation, of which 15 pairs were verified in the analysis of degradome sequencing. Conclusions: The comprehensive analysis of the small RNA, RNA and degradome sequencing data in this study provided candidate genes and clarified the regulatory mechanism of sexual differentiation of G. biloba strobili from multiple perspectives.