| Literature DB >> 30390404 |
David J Studholme1, Preeti Panda2, Eugenio Sanfuentes Von Stowasser3, Mariela González3, Rowena Hill1,4, Christine Sambles1, Murray Grant1,5, Nari M Williams2, Rebecca L McDougal2.
Abstract
Genome sequences were generated for six oomycete isolates collected from forests in Valdivia, Chile. Three of the isolates were identified morphologically as Phytophthora kernoviae, whereas two were similar to other clade 10 Phytophthora species. One isolate was tentatively identified as Nothophytophthora valdiviana based on nucleotide sequence similarity in the cytochrome oxidase 1 gene. This is the first genome sequence for this recently described genus. The genome assembly was more fragmented and contained many duplicated genes when compared with the other Phytophthora sequences. Comparative analyses were performed with genomic sequences of the P. kernoviae isolates from the UK and New Zealand. Although the potential New Zealand origin of P. kernoviae has been suggested, new isolations from Chile had cast doubt on this hypothesis. We present evidence supporting P. kernoviae as having originated in New Zealand. However, investigation of the diversity of oomycete species in Chile has been limited and warrants further exploration. We demonstrate the expediency of genomic analyses in determining phylogenetic relationships between isolates within new and often scantly represented taxonomic groups, such as Phytophthora clade 10 and Nothophytophthora. Data are available on GenBank via BioProject accession number PRJNA352331.Entities:
Keywords: zzm321990Drimys winterizzm321990; zzm321990Eucalyptus nitenszzm321990; zzm321990Nothophytophthorazzm321990; zzm321990Phytophthorazzm321990; forest disease; hybrid; oomycete
Mesh:
Year: 2018 PMID: 30390404 PMCID: PMC6637878 DOI: 10.1111/mpp.12765
Source DB: PubMed Journal: Mol Plant Pathol ISSN: 1364-3703 Impact factor: 5.663
Isolates used in this study and summary statistics for genome sequence data.
| Isolate | Year of isolation | Source/host | Region | Accession numbers: GenBank and SRA | Total size (bp) | Coverage depth | Number of scaffolds | Scaffold N50 (bp) | Number of annotated gene models | Repeat content (%) |
|---|---|---|---|---|---|---|---|---|---|---|
| Chile 1 | 2014 | Baited leaf litter from | Llancahue, Valdivia, Chile | MBAB00000000, SRR4865694 | 38 111 184 | 50× | 2422 | 62 563 | 9914 | 14.27 |
| Chile 2 | 2012 | Baited leaf litter from | Llancahue, Valdivia, Chile | MAYM00000000, SRR4865680 | 38 203 779 | 92× | 2393 | 64 455 | 9922 | 13.88 |
| Chile 4 | 2012 | Baited leaf litter from | Llancahue, Valdivia, Chile | MBDN00000000, SRR4865689 | 37 458 212 | 50× | 2034 | 64 544 | 9877 | 11.18 |
| Chile 5 | 2014 |
| Ciruelos, Valdivia, Chile | MBAC00000000, SRR4865670 | 84 445 542 | 40× | 11 901 | 15 776 | 11 952 | 16.48 |
| Chile 6 | 2014 | Baited leaf litter from | Ciruelos, Valdivia, Chile | MBDO00000000, SRR4865676 | 36 780 765 | 57× | 1910 | 63 953 | 10 093 | 10.72 |
| Chile 7 | 2014 | Baited soil from mixed forest ( | Caramávida, Los Álamos, Chile | MBAD00000000, SRR4865684 | 37 002 228 | 30× | 2830 | 33 020 | 10 129 | 12.11 |
BUSCO (Benchmarking Universal Single‐Copy Orthologs) analysis for annotated genes and proteins.
| BUSCO analysis of genome sequences | BUSCO analysis of predicted protein sequences | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Isolate | Complete genes (% complete) | Complete and single‐copy proteins | Complete and duplicated proteins | Fragmented genes | Missing genes | Complete proteins (% complete) | Complete and single‐copy proteins | Complete and duplicated proteins | Fragmented proteins | Missing proteins | Reference |
| Chile 1 | 229 (97.9) | 229 | 0 | 3 | 2 | 205 (87.6) | 205 | 0 | 8 | 21 | This study |
| Chile 2 | 228 (97.4) | 228 | 0 | 3 | 3 | 205 (87.6) | 205 | 0 | 8 | 21 | This study |
| Chile 4 | 228 (97.4) | 228 | 0 | 3 | 3 | 204 (87.6) | 204 | 0 | 7 | 23 | This study |
| Chile 5 | 205 (87.6) | 41 | 164 | 4 | 25 | 163 (69.6) | 41 | 122 | 9 | 62 | This study |
| Chile 6 | 228 (97.4) | 227 | 1 | 4 | 2 | 203 (86.8) | 203 | 0 | 7 | 24 | This study |
| Chile 7 | 224 (95.7) | 223 | 1 | 4 | 6 | 198 (84.6) | 198 | 0 | 8 | 28 | This study |
| 00629/1 | 228 (97.4) | 228 | 0 | 2 | 4 | – | – | – | – | – | Sambles |
| 00238/432 | 229 (97.9) | 229 | 0 | 2 | 3 | 207 | 207 | 0 | 7 | 20 | Sambles |
| 00844/4 | 229 (97.9) | 229 | 0 | 2 | 3 | – | – | – | – | – | Sambles |
| CBS 122049 | 213 (91.1) | 207 | 6 | 5 | 16 | – | – | – | – | – | Feau |
| NZFS 2646 | 230 (98.3) | 230 | 0 | 2 | 2 | 208 | 208 | 0 | 6 | 20 | Studholme |
| NZFS 3630 | 230 (98.3) | 230 | 0 | 2 | 2 | 207 | 207 | 0 | 7 | 20 | Studholme |
*BUSCO coverage when tested with Alveolata–Stramenopile gene set (n = 234 genes) (Simao et al., 2015)
†Reference for dataset description and BUSCO analysis with annotated genes. BUSCO analysis with annotated proteins performed in this study.
‡–, not determined. Genomes from strains 00629/1 and 00844/4 are almost identical to that of 00238/432 (Sambles et al., 2015), and strain CBS 122049 is also very similar to the other UK strains; hence, 00238/432 was used solely to represent the UK strains.
Figure 1Phylogenetic positions of Chilean Phytophthora isolates based on whole‐genome sequencing. Geographical locations of isolation are indicated by country flags (Chile, New Zealand and UK). Genomic sequence reads and the reference genome assembly for New Zealand and UK isolates were obtained from previous studies (Sambles et al., 2015; Studholme et al., 2016). The phylogenetic tree was generated using the Reference Sequence Alignment‐based Phylogeny Builder (REALPHY) tool (Bertels et al., 2014) with RAxML 8.2.9 (Stamatakis, 2014) as its tree builder and Bowtie 2.3.0 for alignment of the genomic sequence reads against the assembled NZFS 2646 reference genome sequence. Bootstrap values are given as percentages of 500 trials. [Colour figure can be viewed at wileyonlinelibrary.com]
Figure 2Average nucleotide identity matrix of Phytophthora sequence identities based on alignments of whole assembled genomes. The colour key represents the pairwise percentage similarity of alignment results from the dnadiff tool in MUMmer v3.23 (Kurtz et al., 2004). [Colour figure can be viewed at wileyonlinelibrary.com]
Figure 3Frequency distributions of relative abundances of major alleles over all genomic sites in sequenced Phytophthora kernoviae genomes. For each isolate, sequence reads were aligned against the appropriate genome assembly using BWA‐mem (Li and Dublin, 2009; Li, 2013). The histogram shows the frequency densities for the relative abundance of the most common nucleotide in blue and the second most abundant nucleotide in red. The histograms have been cropped at 0.1 and 0.9 for clarity. [Colour figure can be viewed at wileyonlinelibrary.com]