Size distribution of the unigenes and CDS.

<p>The blue and red bars indicate unigene and CDS, respectively.</p

The candidates on the relative capsaicinoids biosynthetic pathway.

<p>The blue and red bars represent new candidates and known candidates from Mazourek, 2009.</p

SNP statistical information based on mapping <i>C. frutescens</i> reads in reference to <i>C. annuum</i> contigs.

<p>SNP statistical information based on mapping <i>C. frutescens</i> reads in reference to <i>C. annuum</i> contigs.</p

<em>De Novo</em> Transcriptome Assembly in Chili Pepper (<em>Capsicum frutescens</em>) to Identify Genes Involved in the Biosynthesis of Capsaicinoids

<div><p>The capsaicinoids are a group of compounds produced by chili pepper fruits and are used widely in many fields, especially in medical purposes. The capsaicinoid biosynthetic pathway has not yet been established clearly. To understand more knowledge in biosynthesis of capsaicinoids, we applied RNA-seq for the mixture of placenta and pericarp of pungent pepper (<em>Capsicum frutescens</em> L.). We have assessed the effect of various assembly parameters using different assembly software, and obtained one of the best strategies for <em>de novo</em> assembly of transcriptome data. We obtained a total 54,045 high-quality unigenes (transcripts) using Trinity software. About 92.65% of unigenes showed similarity to the public protein sequences, genome of potato and tomato and pepper (<em>C. annuum</em>) ESTs databases. Our results predicted 3 new structural genes (DHAD, TD, PAT), which filled gaps of the capsaicinoid biosynthetic pathway predicted by Mazourek, and revealed new candidate genes involved in capsaicinoid biosynthesis based on KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. A significant number of SSR (Simple Sequence Repeat) and SNP (Single Nucleotide Polymorphism) markers were predicted in <em>C. frutescens</em> and <em>C. annuum</em> sequences, which will be helpful in the identification of polymorphisms within chili pepper populations. These data will provide new insights to the pathway of capsaicinoid biosynthesis and subsequent research of chili peppers. In addition, our strategy of <em>de novo</em> transcriptome assembly is applicable to a wide range of similar studies.</p> </div

Illustrated the partly distribution (ratio of alignment/short no less than 0.8) of homologous length and aligned length.

<p>The X axis represents the ratio is length of pepper EST/unigene length, the Y axis is represents the ratio of alignment length/shorter between pepper EST and unigene.</p

Comparison of <i>de novo</i> assembly using Trinity and Velvet-oases programs.

*<p>Represents the number of contigs that at less 200 bp in length.</p>#<p>represents the result of TIGCL and Phrap for reduce the redundancy after Trinity with 25-mer assembly.</p

The results of annotation on unigenes by different databases.

<p>Note:</p>1<p>presents the unigenes annotated by whole protein sequences using blastx,</p>2<p>presents the unigenes annotated by whole genome using blat.</p

Identity new transcripts (genes) on the capsaicinoids biosynthetic pathway.

<p>Identity new transcripts (genes) on the capsaicinoids biosynthetic pathway.</p

The number of SSR in all unigenes and CDS.

<p>The blue bar represents SSR markers in all unigenes, and the red bar represents SSR markers in CDS.</p

Data_Sheet_2_Systematic Analysis of the R2R3-MYB Family in Camellia sinensis: Evidence for Galloylated Catechins Biosynthesis Regulation.xlsx

The R2R3-MYB transcription factor (TF) family regulates metabolism of phenylpropanoids in various plant lineages. Species-expanded or specific MYB TFs may regulate species-specific metabolite biosynthesis including phenylpropanoid-derived bioactive products. Camellia sinensis produces an abundance of specialized metabolites, which makes it an excellent model for digging into the genetic regulation of plant-specific metabolite biosynthesis. The most abundant health-promoting metabolites in tea are galloylated catechins, and the most bioactive of the galloylated catechins, epigallocatechin gallate (EGCG), is specifically relative abundant in C. sinensis. However, the transcriptional regulation of galloylated catechin biosynthesis remains elusive. This study mined the R2R3-MYB TFs associated with galloylated catechin biosynthesis in C. sinensis. A total of 118 R2R3-MYB proteins, classified into 38 subgroups, were identified. R2R3-MYB subgroups specific to or expanded in C. sinensis were hypothesized to be essential to evolutionary diversification of tea-specialized metabolites. Notably, nine of these R2R3-MYB genes were expressed preferentially in apical buds (ABs) and young leaves, exactly where galloylated catechins accumulate. Three putative R2R3-MYB genes displayed strong correlation with key galloylated catechin biosynthesis genes, suggesting a role in regulating biosynthesis of epicatechin gallate (ECG) and EGCG. Overall, this study paves the way to reveal the transcriptional regulation of galloylated catechins in C. sinensis.</p