Statistical summary of <i>Rafflesia cantleyi</i> sequence data.

<p>Statistical summary of <i>Rafflesia cantleyi</i> sequence data.</p

Species distribution of annotated <i>Rafflesia cantleyi</i> flower transcripts.

<p>Species distribution of annotated <i>Rafflesia cantleyi</i> flower transcripts.</p

Comparison of <i>de novo</i> assembly data using Oases, Trinity and CLC Genomics Workbench.

<p>Comparison of <i>de novo</i> assembly data using Oases, Trinity and CLC Genomics Workbench.</p

The pathways and products involved in plant hormone signal transduction.

<p>The pathways and products involved in plant hormone signal transduction.</p

Heat map of selected genes that are differentially expressed between the developing flower and the floral bud of <i>Rafflesia cantleyi</i>.

<p>Heat map of selected genes that are differentially expressed between the developing flower and the floral bud of <i>Rafflesia cantleyi</i>.</p

Top KEGG pathways represented in the <i>Rafflesia cantleyi</i> flower transcriptome.

<p>Top KEGG pathways represented in the <i>Rafflesia cantleyi</i> flower transcriptome.</p

Perigone Lobe Transcriptome Analysis Provides Insights into <i>Rafflesia cantleyi</i> Flower Development

<div><p><i>Rafflesia</i> is a biologically enigmatic species that is very rare in occurrence and possesses an extraordinary morphology. This parasitic plant produces a gigantic flower up to one metre in diameter with no leaves, stem or roots. However, little is known about the floral biology of this species especially at the molecular level. In an effort to address this issue, we have generated and characterised the transcriptome of the <i>Rafflesia cantleyi</i> flower, and performed a comparison with the transcriptome of its floral bud to predict genes that are expressed and regulated during flower development. Approximately 40 million sequencing reads were generated and assembled <i>de novo</i> into 18,053 transcripts with an average length of 641 bp. Of these, more than 79% of the transcripts had significant matches to annotated sequences in the public protein database. A total of 11,756 and 7,891 transcripts were assigned to Gene Ontology categories and clusters of orthologous groups respectively. In addition, 6,019 transcripts could be mapped to 129 pathways in Kyoto Encyclopaedia of Genes and Genomes Pathway database. Digital abundance analysis identified 52 transcripts with very high expression in the flower transcriptome of <i>R</i>. <i>cantleyi</i>. Subsequently, analysis of differential expression between developing flower and the floral bud revealed a set of 105 transcripts with potential role in flower development. Our work presents a deep transcriptome resource analysis for the developing flower of <i>R</i>. <i>cantleyi</i>. Genes potentially involved in the growth and development of the <i>R</i>. <i>cantleyi</i> flower were identified and provide insights into biological processes that occur during flower development.</p></div

RT-qPCR validation of transcript abundance from RNA-seq analysis.

<p>(A) Relative expression of eight genes based on actin as the reference housekeeping gene. Y-axis is shown in log base 2 scale for clearer representation of genes with low expression values. (B) Correlation analysis of relative gene expression values from RT-qPCR and RNA-seq analysis. Genes studied include adenosylhomocysteinase (AHCY), chitinase (CHI), ethylene responsive transcription factor (ERF), MYB transcription factor (MYB), selenium binding protein (SBP), thaumatin-like protein (TLP), glutamate dehydrogenase (GDH) and sucrose synthase (SUS). The relative expression for RT-qPCR was calculated by using the 2^-ΔCt method based on the reference gene, actin; whereas the relative expression values for RNA-seq are FPKM ratios of individual genes relative to that of actin.</p

Length distribution of <i>Rafflesia cantleyi</i> flower transcripts obtained from <i>de novo</i> assembly.

<p>Length distribution of <i>Rafflesia cantleyi</i> flower transcripts obtained from <i>de novo</i> assembly.</p

The <i>Rafflesia cantleyi</i> flower collected from Lata Jarum, Pahang, Malaysia.

<p>The <i>Rafflesia cantleyi</i> flower collected from Lata Jarum, Pahang, Malaysia.</p