Rafflesia tuanku-halimii (Rafflesiaceae), a new species from Peninsular Malaysia

Rafflesia tuanku-halimii, a new species from Peninsular Malaysia, is herewith described and illustrated. It is related to R. azlanii and R. sharifah-hapsahiae by coalesced warts on it lobes. Rafflesia tuanku-halimii is different from them in having window covered by almost united rings and these rings almost wholly covering the window

A new Nepenthes from Gunong Besar, Kalimantan Selatan, Borneo

Volume: 42Start Page: 25End Page: 2

RNA-seq data from different developmental stages of Rafflesia cantleyi floral buds

Rafflesia cantleyi, known as one of the world's largest flowers, is a specialised holoparasite due to dramatic morphological modifications. It possesses highly reduced vegetative structure and only appears as a flower for sexual reproduction. Moreover, it has an unusual life cycle in that its floral bud development takes up to nine months. In order to fully understand the highly modified floral organ structure and long life cycle of R. cantleyi, we used Illumina sequencing technology (HiSeq) for sequence generation followed by de novo assembly of sequence reads. We obtained the RNA-seq data from three different stages of floral bud, representing the early, mid and advanced developmental stages. These data are available via BioProject accession number PRJNA378435. More than 10.3 Gb raw sequence data were generated, corresponding to 102,203,042 raw reads. Following removal of low-quality reads and trimming of adapter sequences, a total of 91,638,836 reads were obtained. De novo assembly of these sequences using Trinity resulted in 89,690 unique transcripts with an N50 of 1653 bp. The obtained transcriptomic data will be useful for further study to understand the molecular interactions that result in R. cantleyi floral development

Transcriptome landscape of Rafflesia cantleyi floral buds reveals insights into the roles of transcription factors and phytohormones in flower development.

Rafflesia possesses unique biological features and known primarily for producing the world's largest and existing as a single flower. However, to date, little is known about key regulators participating in Rafflesia flower development. In order to further understand the molecular mechanism that regulates Rafflesia cantleyi flower development, RNA-seq data from three developmental stages of floral bud, representing the floral organ primordia initiation, floral organ differentiation, and floral bud outgrowth, were analysed. A total of 89,890 transcripts were assembled of which up to 35% could be annotated based on homology search. Advanced transcriptome analysis using K-mean clustering on the differentially expressed genes (DEGs) was able to identify 12 expression clusters that reflect major trends and key transitional states, which correlate to specific developmental stages. Through this, comparative gene expression analysis of different floral bud stages identified various transcription factors related to flower development. The members of WRKY, NAC, bHLH, and MYB families are the most represented among the DEGs, suggesting their important function in flower development. Furthermore, pathway enrichment analysis also revealed DEGs that are involved in various phytohormone signal transduction events such as auxin and auxin transport, cytokinin and gibberellin biosynthesis. Results of this study imply that transcription factors and phytohormone signalling pathways play major role in Rafflesia floral bud development. This study provides an invaluable resource for molecular studies of the flower development process in Rafflesia and other plant species

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

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

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

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

The pathways and products involved in plant hormone signal transduction.

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