RNA-Seq Analysis Reveals Genetic Bases of the Flowering Process in Oriental Hybrid Lily cv. Sorbonne

Abstract

Flowering is a critical step in plant reproduction. Oriental lily (Lilium) characterized by showy flowers is increasingly used; however, the blossom period is an important limiting factor influencing the value of lily. Improving the flowering of lily by molecular breeding technology has limitless applications, but the mechanism of the regulation of lily flowering remains to be studied. Transcriptomes providing comprehensive sequence profiling data of transcription variation during flowering process in Oriental hybrids lily Sorbonne were assembled from RNA Seq data. Approximately 124.16 million 90 bp paired end clean reads were assembled into 66 327 unigenes and compared with the UniProt databases. There are 30 254 unigenes that have significant hits to the sequences in the UniProt database, 60 738, 16 601, and 12 494 unigenes have sim ilarity to the GO, KEGG, and COG databases, respectively. By analyzing dynamic changes in the transcrip tome of lily flowering based on our RNA sequencing (RNA Seq) data, some genes involved in floral induc tion were found, which revealed the complicated flower regulation network at the transcriptome level during lily flowering. Moreover, 12 DEGs related to flowering including LoLFY, LoMAF, LoFT, LoAG, LoCBF, LoAGL6a, LoSOC1, LoSEP1, LoNAC1, LoAPX, LoARF10, and LoICE were identified with real time quan titative RT PCR analysis. The results suggested that the flower of Oriental lily possessed a high proportion of flowering genes active at different stages of flowering. According to the results of the present study, we pre dicted that they would play an important role during flowering process; these data provided the foundation for future studies of metabolism during flowering of Oriental lily.