Transcriptome analysis of a taxol-producing endophytic fungus Cladosporium cladosporioides MD2

Li-Yun Miao,You-Sheng Ke,Xin-Chun Mo,Pan Liu,Fa-Jun Song,Xiao-Yuan Xi,Ge De,Wen-Wen Jin,Peng Zhang,Lan Zhou

doi:10.1186/s13568-018-0567-6

Abstract

The shortage of molecular information for taxol-producing fungi has greatly impeded the understanding of fungal taxol biosynthesis mechanism. In this study, the transcriptome of one taxol-producing endophytic fungus Cladosporium cladosporioides MD2 was sequenced for the first time. About 1.77 Gbp clean reads were generated and further assembled into 16,603 unigenes with an average length of 1110 bp. All of the unigenes were annotated against seven public databases to present the transcriptome characteristics of C. cladosporioides MD2. A total of 12,479 unigenes could be annotated with at least one database, and 1593 unigenes could be annotated in all queried databases. In total, 8425 and 3350 unigenes were categorized into 57 GO functional groups and 262 KEGG pathways, respectively, exhibiting the dominant GO terms and metabolic pathways in the C. cladosporioides MD2 transcriptome. One potential and partial taxol biosynthetic pathway was speculated including 9 unigenes related to terpenoid backbone biosynthesis and 40 unigenes involved in the biosynthetic steps from geranylgeranyl diphosphate to 10-deacetylbaccatin III. These results provided valuable information for the molecular mechanism research of taxol biosynthesis in C. cladosporioides MD2.

Highlights

IntroductionTaxol ( named as Paclitaxel) originally isolated from Taxus brevifolia (Wani et al 1971) was well-known as an anti-cancer drug used in clinic
Taxol originally isolated from Taxus brevifolia (Wani et al 1971) was well-known as an anti-cancer drug used in clinic
Transcriptome sequencing and assembly The transcriptome of C. cladosporioides MD2 was sequenced with Illumina sequencing technology to generate 19,776,638 raw reads consisting of 1,779,897,420 nucleotides

Summary

Introduction

Taxol ( named as Paclitaxel) originally isolated from Taxus brevifolia (Wani et al 1971) was well-known as an anti-cancer drug used in clinic. Since one taxolproducing endophytic fungus Taxomyce andreanae isolated from the bark of T. brevifolia was firstly reported (Stierle et al 1993), more than 40 fungal genera about. 200 endophytic fungi had been reported to produce taxol (Flores-Bustamante et al 2010; Kusari et al 2014). Targeted genetic engineering of taxolproducing fungi was an effective way to exploit their taxol productivity, there were difficult challenges due to the almost complete lack of molecular information on the exact pathway, key rate-limiting steps, and availability of a complete set of genes involved in the taxol biosynthesis of fungi (Flores-Bustamante et al 2010; Gond et al 2014). A prerequisite was to discover taxol-related genes and uncover the molecular mechanism of taxol biosynthesis in fungi (Flores-Bustamante et al 2010; Kusari et al 2014)

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Results

Conclusion