Identification and characterization of long non-coding RNAs involved in embryo development of Ginkgo biloba

Abstract
Long non-coding RNAs (lncRNAs) are important regulatory factors for plant growth and development. Despite this, little is known about the regulatory interactions of lncRNAs with mRNA during embryo development. Here, we used a bioinformatics genome-wide approach to identify lncRNAs involved in embryo development of Ginkgo biloba, based on RNA sequencing datasets from G. biloba embryos during early, middle, late developmental stages. In total, 2326 lncRNAs were identified in the G. biloba embryos, of which 1307 and 1019 could be classified as long intergenic non-coding RNAs and antisense lncRNAs, respectively. Among them, a total of 657 differentially expressed lncRNAs were identified in the different developmental stages of the G. biloba embryos. Based on the functional annotation of potential target genes of lncRNAs, 50, 33, and 76 lncRNAs were predicted to target genes involved in plant hormone signal transduction, plant hormone biosynthesis, and circadian rhythm regulation, respectively. A lncRNA (17)-miRNA (25)-PCgene (52) network was constructed for the G. biloba embryo. Three lncRNAs (lnc000823, lnc002072, lnc000866) were predicted as target mimics of miR159, which targeted two transcription factors with variety of functions, Gb_11536 (MYB33) and Gb_23921 (MYB101). The data generated in this study provide a better understanding of the roles of lncRNAs in embryo development of G. biloba and plants in general.