De novo sequencing and comparative analysis of two Phalaenopsis orchid tissue-specific transcriptomes

Abstract

In recent years, Phalaenopsis has become a very popular potted flower for the international flower market. The aim of this work was to build a tissue-specific transcriptome to obtain genomic data about the biosynthesis of anthocyanins in Phalaenopsis, compare gene expression levels in different colored Phalaenopsis plants, and to ultimately analyze the anthocyanin biosynthetic pathway in Phalaenopsis. Illumina sequencing technology obtained 888749 and 1057077 sequencing contigs in red and yellow Phalaenopsis buds, respectively. De novo assemblies yielded 51771 unigenes, and 801 differentially expressed genes were obtained using the reads. These included 358 up-regulated and 443 down-regulated genes in the yellow bud compared with the red bud. Many of the identified differentially expressed genes were related to the biosynthesis of anthocyanins. Quantitative real-time PCR confirmed expression levels of key genes and transcription factors involved in anthocyanin biosynthesis in Phalaenopsis were the same as in our dataset. Our findings allowed the deduction of the anthocyanin biosynthetic pathway in Phalaenopsis.