Fig 1.
Morphology of Rafflesia cantleyi floral bud developmental stages.
Longitudinal section of (A) floral bud stage 1 with the initiation of reproductive development, (B) floral bud stage 2 of with organ differentiation and outgrowth, and (C) floral bud stage 3 with fully developed floral organs for blooming. Structures identified are perianth lobes (1), diaphragm (2), floral chamber (3), reproductive column (4) and ramenta (5).
Fig 2.
COG classification of Rafflesia cantleyi floral bud transcripts.
A total of 7,172 transcripts were assigned to 25 COG categories. The y-axis indicates the number of transcripts in each category.
Fig 3.
Gene Ontology functional classification of Rafflesia cantleyi floral bud transcriptome.
The results are summarised in three GO categories: biological process, molecular function and cellular component. The y-axis indicates the number of transcripts in each category.
Fig 4.
Number of DEGs in different comparisons, including FBS1 vs. FBS2, FBS2 vs. FBS3, and FBS1 vs. FBS3.
Significant DEGs were defined by P-value ≤ 0.001 with FDR ≤ 0.05 and |Log2 fold change| > 2. Left bar represents up-regulated transcripts and right bar represents down-regulated transcripts.
Fig 5.
Expression profile analysis of DEGs in Rafflesia cantleyi floral bud development.
(A) MeV cluster analysis of DEGs from the expression profiles across three floral bud stages (FBS1, FBS2 and FBS3). Main line in each of the 12 cluster graphs indicates the average expression level of transcripts grouped into the same cluster under different floral bud stages. (B) Heatmap for cluster analysis of the DEGs by the K-means method with reference to the scale bar at the top of the figure.
Fig 6.
Analysis of transcription factors associated with flower development in Rafflesia cantleyi.
A heat map depicting the overall trend of the differential expression profiles of the transcription factor during flower development with reference to the scale bar at the top of the figure. The number of DEGs in each transcription factor family is shown in parentheses.
Fig 7.
Heat map analysis of various hormones involved in the regulation of flowering process.
Log2-transcription FPKM values of each gene correspond to the scale bar at the bottom of the figure. Crosstalk between different hormones during flower development is shown as overlapping borders.
Fig 8.
RT-qPCR validation of RNA-seq analysis.
(A) Expression of twelve genes related to flower development in different stages of R. cantleyi floral bud development based on three independent biological replicates. Error bars show ± SD of three technical replicates of the three biological replicates. (B) Scatter plot of fold change (FC) of 12 selected gene expression ratios from RT-qPCR and RNA-Seq data. Squares correspond to FBS1-FBS2 and triangles correspond to FBS1-FBS3 comparison.
Fig 9.
Pathway connection of hormonal signal transduction obtained from GO enrichment analysis of DEGs in Rafflesia cantleyi.
GO enrichment analysis revealed DEGs involved in various phytohormones metabolism and signal transduction processes.