Identification of the candidate genes related to sanshool biosynthesis in Zanthoxylum bungeanum by comparative RNA sequencing analysis

Abstract

Zanthoxylum bungeanum is an edible and medicinal plant with great economic value in East Asia due to high sanshool content in its pericarp. Sanshools not only provide a unique pungency in cuisine, but also have potential for use in anaesthetics, anticancer drugs, and botanical safeners. In this study, to identify the candidate genes related to sanshool biosynthesis, the transcriptomes of pericarps from three developmental stages were comparatively analysed. According to differentially expressed gene (DEG) analysis, 2322 unigenes were upregulated or downregulated significantly among the three types of pericarps and 176 of the DEGs were putative transcription factors (TFs) belonging to 40 TF families. Furthermore, based on the chemical structure of sanshools and unigene annotation, DEGs involved in the pathways of fatty acid biosynthesis and metabolism and amino acid transport were predicted. These DEGs were related to sanshool biosynthesis and 12 candidate enzymes encoded by 18 unigenes were related to the biosynthesis and metabolism of sanshools and identified and classified into three groups. This study provides a global survey of gene expression patterns in pericarp development of Z. bungeanum, which offers clues regarding important regulatory mechanisms, especially with respect to sanshool biosynthesis in the pericarp of Z. bungeanum.