Draft genomes of two Australian strains of the plant pathogen, Phytophthora cinnamomi

Abstract

Background: The oomycete plant pathogen, Phytophthora cinnamomi, is responsible for the destruction of thousands of species of native Australian plants, as well as several crops, such as avocado and macadamia, and has one of the widest host-plant ranges of the Phytophthora genus. The current reference genome of P. cinnamomi is based on an atypical strain and has large gaps in its assembly. To further studies of the pathogenicity of this species, especially in Australia, robust genome assemblies of more typical strains are required. Here we report the genome sequencing, draft assembly, and preliminary annotation of two geographically separated Australian strains of P. cinnamomi. Findings: Some 308 million raw reads were generated for the two strains, DU054 and WA94.26. Independent genome assembly produced final genome sequences of 62.8 Mb (in 14,268 scaffolds) and 68.1 Mb (in 10,084 scaffolds), which are comparable in size and contiguity to other Phytophthora genomes. Gene prediction yielded > 22,000 predicted protein-encoding genes within each genome, while BUSCO assessment showed 94.4% and 91.5% of the stramenopile single-copy orthologs to be present in the assembled genomes, respectively. Conclusions: The assembled genomes of two geographically distant isolates of Phytophthora cinnamomi will provide a valuable resource for further comparative analyses and evolutionary studies of this destructive pathogen, and further annotation of the presented genomes may yield possible targets for novel pathogen control methods.

Keywords: Phytophthora cinnamomi; Phytophthora genome; plant pathogen.