Dataset Information

Characterization of the complete mitochondrial genome of Cercospora nicotianae (Ellis & Everh, 1893) (Dothideomycetes: Capnodiales)

ABSTRACT: Abstract The mitochondrial genome of the fungal pathogen Cercospora nicotianae was sequenced for the first time using a combination of Illumina and Nanopore sequencing technologies. The circular genome is 27,737 bp in length with G + C content of 27.43%, consisting of 15 protein-coding genes, 26 transfer RNA genes and 2 ribosomal RNA genes. Phylogenetic analysis shows that the C. nicotianae mtDNA is closely related to Pseudocercospora fijiensis.

SUBMITTER: Lu N

PROVIDER: S-EPMC8725932 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The photoactivated toxin, cercosporin, produced by Cercospora species, plays an important role in pathogenesis of this fungus to host plants. Cercosporin has almost universal toxicity to cells due to its production of reactive oxygen species including singlet oxygen. For that reason, Cercospora species, which are highly resistant to their own toxin, are good candidates to identify genes for resistance to cercosporin and to the reactive oxygen species it produces. In previous research, the zinc cluster transcription factor CRG1 (cercosporin resistance gene 1) was found to be crucial for Cercospora species' resistance against cercosporin, and subtractive hybridization analysis identified 185 genes differentially expressed between Cercospora nicotianae wild type (wt) and a crg1 mutant. The focus of this work was to identify and characterize the hypothetical proteins that were identified in the Cercospora nicotianae subtractive library as potential resistance factors. Quantitative RT-PCR analysis of the 20 genes encoding hypothetical proteins showed that two, 24cF and 71cR, were induced under conditions of cercosporin toxicity, suggesting a role in resistance. Transformation and expression of 24cF and 71cR in the cercosporin-sensitive fungus, Neurospora crassa, showed that 71cR provided increased resistance to cercosporin toxicity, whereas no significant increase was observed in 24cF transformants. Gene disruption was used to generate C. nicotianae 71cR mutants; these mutants did not differ from wt C. nicotianae in cercosporin resistance or production. Quantitative RT-PCR analysis showed induction of other resistance genes in the 71cR mutant that may compensate for the loss of 71cR. Analysis of 71cR conserved domains and secondary and tertiary structure identify the protein as having an NTF2-like superfamily DUF1348 domain with unknown function, to be intracellular and localized in the cytosol, and to have similarities to proteins in the steroid delta-isomerase family.

Project description:Phytophthora nicotianae is one of the most destructive plant pathogens affecting a variety of plants, causing black shank of tobacco, among several other devastating diseases. Herein, we assembled the mitochondrial genome of P. nicotianae and analyzed its gene content and genome structure, performed comparative mitochondrial genomics analysis, and assessed phylogenetic relationships among oomycetes species. The circular mitogenome is 37,561 bp long, with 38 protein-coding genes, 25 transfer RNA (tRNA) genes, and 2 ribosomal RNA genes (rrnl and rrns). The mitochondrial genome showed a biased A/T usage versus G/C. The overall gene content and size of the P. nicotianae mitogenome are identical to those of other published Phytophthora mitogenomes. Interestingly, collinearity analysis using an existing ?10 k inversion region (including 11 genes and 8 tRNAs) revealed that Phytophthora andina, Phytophthora infestans, Phytophthora mirabilis, Phytophthora ipomoeae, and Phytophthora phaseoli differed from Phytophthora nicotianae, Phytophthora sojae, Phytophthora ramorum, and Phytophthora polonica. Moreover, inverted repeat regions were found to be absent among species of the Peronosporales when compared with species from the Pythiales and Saprolegniales. A phylogenomic investigation based on 29 protein-coding genes demonstrated that Phytophthora is monophyletic, and placed P. nicotianae close to the clade including P. mirabilis, P. ipomoeae, P. andina, P. infestans, and P. phaseoli. Furthermore, we discovered six new candidate DNA molecular markers (rpl6, atp8, nad11, rps2, rps3, and rps4) based on these mitogenomes that would be suitable for species identification in the oomycetes, which have the same identification level as the whole mitogenome and ribosomal DNA sequences. These new molecular markers can not only provide a quick preview of the species without mitogenome information, but will also help to gain better understanding of the oomycetes pathogens and developing treatment or monitoring strategies.

Dataset Information

Characterization of the complete mitochondrial genome of Cercospora nicotianae (Ellis & Everh, 1893) (Dothideomycetes: Capnodiales)

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure