Virus communities are associated with the degradation of recalcitrant carbon during the corpse decay of plateau pika (Ochoton curzoniae)

Background

It has been reported that bacteria and fungi play a vital role in soil biogeochemical cycles during the decomposition of animal corpses. However, it is poorly understood how the viral composition and function of grassland soil change during the decay of wild mammal corpses.

Methods

Here, we tracked soil viral succession in the 94-day decomposition of mammalian (plateau pika) wildlife corpses through metagenomic analysis, 16S rRNA gene sequencing, and soil physicochemical assessment.

Results

A total of 2413 virus species were detected, and Podoviridae, Poxviridae, Mimiviridae, and Siphoviridae were abundant in the gravesoil (soil beneath the corpse). Viral diversity first followed a trend of decline and then increased in the gravesoil with succession time. Total carbon in the gravesoil had a significant negative correlation with viral diversity and Myoviridae. Stochastic processes dominated the assembly of viral communities and decreased with succession time in both control and gravesoil groups. The network interactions between viruses and bacteria became more complex and tighter, indicating a closer and mutualistic virus–host relationship during carrion decay. Notably, the major virus-associated carbon function involved the degradation of recalcitrant carbon (e.g., lignin, chitin, pectin, and cellulose).

Conclusions

Our study broadens the understanding of the functional role of viruses that participate in the biochemical cycle of grassland soil during the decay of animal remains.