Abstract
Ovule development is pivotal to plant reproduction and seed development. Cymbidium sinense (Orchidaceae) has high ornamental value due to its pleasant aroma and elegant floral morphology. The regulatory mechanism underlying ovule development in orchids, especially C. sinense, is largely unknown and information on the C. sinense genome is very scarce. In this study, a combined analysis was performed on the transcriptome and non-targeted metabolomes of 18 C. sinense ‘Qi Jian Hei Mo’ ovule samples. Transcriptome analysis assembled gene-related information related to six growth stages of C. sinense ovules (S1-S6, equivalent to 30, 35, 42, 46, 53, and 60 days after pollination). Illumina sequencing technology was used to obtain the complete set of transcriptome sequences of the 18 samples. A total of 81,585 unigene sequences were obtained after assembly, 24,860 (30.47%) of which were functionally annotated. Using transcriptome sequencing technology, a total of 9845 differentially expressed unigenes (DEUs) were identified in C. sinense ovules that were assigned to specific metabolic pathways according to the Kyoto Encyclopedia of Genes and Genomes (KEGG). DEUs associated with transcription factors (TFs) and phytohormones were identified and analyzed. The TFs homeobox and MADS-box were associated with C. sinense ovule development. In particular, the phytohormones associated with DEUs such as indole-3-acetic acid (IAA), cytokinin (CK), gibberellin (GA), abscisic acid (ABA), brassinosteroid (BR), and jasmonate (JA), may have important regulatory effects on C. sinense ovule development. Metabolomic analysis showed an inconsistent number of KEGG annotations of differential metabolites across comparisons (S2_vs_S4, S2_vs_S5, and S4_vs_S5 contained 23, 26, and 3 annotations, respectively) in C. sinense ovules. This study provides a valuable foundation for further understanding the regulation of orchid ovule development and formation, and establishes a theoretical background for future practical applications during orchid cultivation.
Highlights
Cymbidium sinense (Orchidaceae) is an economically important flowering orchid with high ornamental value, elegant color, and delicate scent (Huang and Dai, 1998; Kim et al, 2016)
To study the system-wide changes in the C. sinense ovule during differential developmental stages (S1–S6), we obtained the transcriptomic data of 18 C. sinense ovule samples
We identified growth- and development-related transcription factors (TFs) such as homeobox and MADS-box TFs, as well as plant hormones such as auxin, CK and BR, which may be feasibly involved in C. sinense ovule development
Summary
Cymbidium sinense (Orchidaceae) is an economically important flowering orchid with high ornamental value, elegant color, and delicate scent (Huang and Dai, 1998; Kim et al, 2016). Members of the Orchidaceae account for a high proportion of all flowering plants, they have highly diversified and specialized flower morphology. The Orchidaceae has a unique flower type with a characteristic column (Rudall and Bateman, 2002). Pollinia are found at the top of the column while the ovary, which develops postpollination, is found at the bottom of it (Yu and Goh, 2001). The ovule develops into a seed after fertilization and ensures normal reproduction and the production of offspring (Schneitz, 1999), which is regarded as an important biological process during plant development
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
