Chromosome-level genome assemblies of the pink snow mold pathogens Microdochium majus and Microdochium nivale

Area of Science:

• Plant pathology
• Genomics
• Fungal genetics

Background:

• Wheat Snow Mold (WSM), caused by Microdochium species, significantly impacts global wheat production.
• The genetic and molecular mechanisms underlying Microdochium pathogenicity are poorly understood.
• Genome-wide differences between M. majus and M. nivale, previously grouped as one species, remain largely unelucidated.

Purpose of the Study:

• To generate high-quality, telomere-to-telomere genome assemblies for M. majus and M. nivale.
• To perform comparative genomics to understand genome-wide differences and similarities between these two species.
• To lay the foundation for future research into the genetic evolution and disease management of Microdochium.

Main Methods:

• Utilized Nanopore and Illumina sequencing technologies for genome assembly.
• Anchored genome assemblies to chromosomes and sequenced the mitochondrial genome.
• Employed comparative genomics to analyze gene content, collinearity, and structural variations.

Main Results:

• Successfully assembled the genomes of M. majus (36.50 Mb) and M. nivale (37.27 Mb), each anchored to 13 chromosomes and a circular mitochondrial genome.
• Identified 11,432 protein-coding genes in M. majus and 11,904 in M. nivale, with high functional annotation rates (96.9% and 96.7%, respectively).
• Comparative analysis revealed significant genome collinearity alongside segment rearrangements and gene presence/absence variations between the two species.

Conclusions:

• The study presents the first comprehensive genome assemblies for M. majus and M. nivale, significantly advancing the understanding of their genetic makeup.
• These high-quality genomes provide crucial insights into the genetic divergence and evolutionary relationships between these two important wheat pathogens.
• The findings establish a critical resource for future investigations into Microdochium genetics, virulence, and the development of effective disease management strategies for Wheat Snow Mold.