Genome Assemblies Reveal Distinct Genomic Features of Pine Pathogen Diplodia Sapinea

Strategic Insights -

Researchers from the University of Pretoria have made significant strides in understanding the genomic structure of the latent pine pathogen Diplodia sapinea. By generating chromosome-level genome assemblies for three D. sapinea isolates and low-coverage Illumina genome data for six additional isolates, the team identified 14 core chromosomes and two accessory chromosomes (ACs) in the pathogen. These ACs, which encode 80 and 147 proteins, respectively, are thought to be evolutionary hotspots, with sequence analysis indicating more sequence variation compared to genes on the core chromosomes.

Key Takeaways:

  • The research identified 14 core chromosomes and two accessory chromosomes (ACs) in D. sapinea.
  • The two ACs encode 80 and 147 proteins, respectively, and have lower gene density and higher proportions of transposable elements compared to the core chromosomes.
  • The ACs are thought to be evolutionary hotspots, with sequence analysis indicating more sequence variation compared to genes on the core chromosomes.
  • Pathogenicity trials on Pinus patula seedlings showed no correlation between the presence of ACs and isolate aggressiveness.
  • The high-quality genomes provided offer important resources for future research on D. sapinea, including the biological roles of the ACs.
  • The research highlights the importance of understanding the genomic structure of D. sapinea, a globally important pathogen with climate-driven range expansion.

Statistics:

  • 14 core chromosomes and 2 accessory chromosomes (ACs) were identified in D. sapinea.
  • 11374 - 11601 genes were identified in the core chromosomes.
  • 80 and 147 proteins are encoded by the two ACs, respectively.
  • 33 isolates from 13 countries were found to contain one of the ACs.
  • Pathogenicity trials on Pinus patula seedlings showed no correlation between the presence of ACs and isolate aggressiveness.

Sources:

  • Chromosome-level genome assemblies for the latent pine pathogen, Diplodia sapinea, reveal two accessory chromosomes with distinct genomic features and evolutionary dynamics. G3, 2025.
  • University of Pretoria, Department of Biochemistry, Genetics and Microbiology.
  • Oxford Univ Press Inc, Journals Dept.
  • NewsRx. Findings in the Area of Genetics Reported from University of Pretoria (Chromosome-level genome assemblies for the latent pine pathogen, Diplodia sapinea, reveal two accessory chromosomes with distinct genomic features and evolutionary dynamics). Life Science Weekly. October 21, 2025; p 1466.