Comparative Transcriptomic Analysis of Vernalization- and Cytokinin-Induced Floral Transition in Dendrobium nobile

• Published in: Scientific reports Vol. 7; no. 1; p. 45748
• Main Authors: Wen, Zhenzhen, Guo, Wenzhong, Li, Jinchi, Lin, Haisheng, He, Chunmei, Liu, Yunquan, Zhang, Qunyu, Liu, Wei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.03.2017; Nature Publishing Group
• Subjects: 38/91; 631/337/2019; 631/449/2679/2681; Annotations; Biosynthesis; Cold; Data processing; Flowering; Gene expression; Greenhouses; Humanities and Social Sciences; multidisciplinary; Proteins; Ribonucleic acid; RNA; Science; Signal transduction; Temperature; Temperature effects; Thidiazuron; Transcription factors; Vernalization
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep45748

Vernalization is required for floral initiation in Dendrobium . Interestingly, those beneficial effects can also be achieved by exogenous cytokinin application in greenhouses. Thus, an as yet unknown crosstalk/interaction may exist between vernalization and cytokinin signaling pathways. In this study, we showed, by de novo transcriptome assembly using RNA-seq data from both vegetative and reproductive tissue samples, that some floral transition-related genes— DnVRN1, FT, SOC1, LFY and AP1 —were differentially expressed in low-temperature-challenged (LT) or thidiazuron (TDZ)-treated plants, compared to those mock-treated (CK). Both LT and TDZ upregulated SOC1, LFY and AP1 , while the upregulation of DnVRN1 and FT was only LT-induced. We further found that LT promoted the upregulation of some key cytokinin signaling regulators, including several cytokinin biosynthesis-related genes and type-B response regulator (RR)-encoding genes, and that both LT and TDZ triggered the significant upregulation of some marker genes in the gibberellin (GA) signaling pathway, indicating an important low temperature-cytokinin-GA axis in flowering. Our data thus have revealed a cytokinin-GA signal network underlying vernalization, providing a novel insight into further investigation of the molecular mechanism of floral initiation in Dendrobium .