Expansion and Conservation of Biosynthetic Gene Clusters in Pathogenic Pyrenophora spp.

Abstract

Pyrenophora is a fungal genus responsible for a number of major cereal diseases. Although fungi produce many specialised or secondary metabolites for defence and interacting with the surrounding environment, the repertoire of specialised metabolites (SM) within Pyrenophora pathogenic species remains mostly uncharted. In this study, an in-depth comparative analysis of the P. teres f. teres, P teres f. maculata and P. tritici-repentis potential to produce SMs, based on in silico predicted biosynthetic gene clusters (BGCs), was conducted using genome assemblies from PacBio DNA reads. Conservation of BGCs between the Pyrenophora species included type I polyketide synthases, terpene synthases and the first reporting of a type III polyketide synthase in P teres f. maculata. P. teres isolates exhibited substantial expansion of non-ribosomal peptide synthases relative to P. tritici-repentis, hallmarked by the presence of tailoring cis-acting nitrogen methyltransferase domains. P. teres isolates also possessed unique non-ribosomal peptide synthase (NRPS)-indole and indole BGCs, while a P. tritici-repentis phytotoxin BGC for triticone production was absent in P. teres. These differences highlight diversification between the pathogens that reflects their different evolutionary histories, host adaption and lifestyles.

IMA Genome - F15

“…In total, 9378 orthologous groups were common to all three isolates and WAC10721 shared 167 and 122 unique orthologous genes with the P. teres f. teres and P. teres f. maculata reference genome, respectively. Effector proteins and secondary metabolites play important roles in fungal pathogenicity and virulence (Moolhuijzen et al 2020;Muria-Gonzalez et al 2020;Wyatt et al 2020). A total of 1039 predicted proteins in the genome have Fig.…”

Species hybridisation and clonal expansion as a new fungicide resistance evolutionary mechanism in Pyrenophora teres spp

“…Any regions that overlapped with repetitive elements were discarded and the remaining coordinates were used to extract 1 kb intergenic regions. Homologous regions were searched from other Ptt and Ptm genomes sequenced in this study (9193, Ko103, 16FRG073, 17FRG026, and 17FRG089), as well as the previously published genomes of isolates SG1 (Ellwood et al, 2012), NB29, NB85, Cad64 andMur2 (Syme et al, 2018), and 73, 9122 and 9139 (Moolhuijzen et al, 2020) using Basic Local Alignment Search Tool (BLAST) (Altschul et al, 1990), and the best matching regions were extracted to generate multiple sequence alignments for each intergenic regions using MAFFT (Katoh, 2002). The aligned regions were subjected to recombination test using PHIPack (Bruen, 2005).…”

Identification and characterization of Pyrenophora species causing leaf spot on oat (Avena sativa) in western China

“…Drechslera leaf spot (DLS) caused by Pyrenophora species (asexual morph: Drechslera) is common in major cereal-growing areas of the world (Moolhuijzen et al, 2020). Pyrenophora teres and Pyrenophora graminea cause net blotch and leaf stripe of barley (Arabi et al, 2020;Ronen et al, 2019); Pyrenophora tritici-repentis results in wheat disease tan spot (Liu et al, 2020;Loughman & Deverall, 1986;See et al, 2018); and P. dictyoides and P. nobleaewere both cause ryegrass leaf spots (Xue et al, 2020).…”