Transcriptomic analysis of differentially expressed genes in the floral transition of the summer flowering chrysanthemum

Abstract

BackgroundChrysanthemum is a leading cut flower species. Most conventional cultivars flower during the fall, but the Chrysanthemum morifolium ‘Yuuka’ flowers during the summer, thereby filling a gap in the market. To date, investigations of flowering time determination have largely focused on fall-flowering types. Little is known about molecular basis of flowering time in the summer-flowering chrysanthemum. Here, the genome-wide transcriptome of ‘Yuuka’ was acquired using RNA-Seq technology, with a view to shedding light on the molecular basis of the shift to reproductive growth as induced by variation in the photoperiod.ResultsTwo sequencing libraries were prepared from the apical meristem and leaves of plants exposed to short days, three from plants exposed to long days and one from plants sampled before any photoperiod treatment was imposed. From the ~316 million clean reads obtained, 115,300 Unigenes were assembled. In total 70,860 annotated sequences were identified by reference to various databases. A number of transcription factors and genes involved in flowering pathways were found to be differentially transcribed. Under short days, genes acting in the photoperiod and gibberellin pathways might accelerate flowering, while under long days, the trehalose-6-phosphate and sugar signaling pathways might be promoted, while the phytochrome B pathway might block flowering. The differential transcription of eight of the differentially transcribed genes was successfully validated using quantitative real time PCR.ConclusionsA transcriptome analysis of the summer-flowering cultivar ‘Yuuka’ has been described, along with a global analysis of floral transition under various daylengths. The large number of differentially transcribed genes identified confirmed the complexity of the regulatory machinery underlying floral transition.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3024-4) contains supplementary material, which is available to authorized users.

Transcriptome analysis of differentially expressed unigenes involved in flavonoid biosynthesis during flower development of Chrysanthemum morifolium ‘Chuju’

“…Among them, 34,605 unigenes were assigned a specific or general function on the basis of comparison against sequences in the nr, Swiss-Prot, KEGG, COG and GO databases, corresponding to approximately 54.19% of the total unigenes. This value is similar to that in C. morifolium ‘Fenditan’ (47%) 16 , C. morifolium ‘Yuuka’ (60%) 17 and C. lavandulifolium (53%) 28 based on an equivalent strategy of transcriptome analysis.…”

“…In C. morifolium ‘Fenditan’, a large number of transcription factors and structural genes involved in the photoperiod pathway as well as flower organ determination have been identified from whole transcriptome data by using the RNA-Seq technology 16 . Meanwhile, a transcriptome analysis of another cultivar C. morifolium ‘Yuuka’ succeeded in identifying many differentially expressed genes under the treatment of various daylengths 17 . While this technology has been intensively applied for studying flowering-time regulation in ornamental C. morifolium cultivars, but to our knowledge, no transcriptomic analysis regarding the flavonoid biosynthesis has been reported in medicinal C. morifolium cultivars.…”

CmBBX8 accelerates flowering by targeting CmFTL1 directly in summer chrysanthemum

“…In autumn‐flowering, chrysanthemum flowering time is majorly regulated by the photoperiod pathway under SD, and the GA signalling pathway predominated for flowering under LD (Dong et al , ), while the antiflorigen function of AFT under LD obligates the flowering only under SD (Higuchi et al , ). In summer‐flowering chrysanthemum, flowering might be promoted by the photoperiod and GA pathways under SD, and by the T6P and sugar signalling pathways under LD, while the flowering time is delayed by PHYB under LD (Ren et al , ). In our study, it was revealed CmFTL1 regulated flowering time in cv.…”

Combined analysis and miRNA expression profiles of the flowering related genes in common wild rice (oryza rufipogon Griff.)

“…Using high-throughput sequencing, researchers have altered our view of the extent and complexity of eukaryotic transcriptomes, facilitated the discovery of novel genes (Qi et al 2012 ; Wang et al 2009 ). For example, several differentially-transcribed genes related to floral transition were identified in Chrysanthemum by Illumina sequencing (Ren et al 2016 ). Harrop et al ( 2016 ) used gene expression profiling to analyze genes that participated in reproductive meristem development in early rice inflorescences (Harrop et al 2016 ).…”