Limited effect of short- to mid-term storage conditions on an Australian farmland soil RNA virome.
Sadiq S, Xue P, Tang Y, Du M, Van Brussel K
Summary
6.5/10Researchers established practical storage protocols for soil samples used in virome research: standard refrigeration and freezing conditions preserve RNA quality without expensive commercial preservatives, enabling efficient discovery of novel soil viruses—1,475 identified in this study alone.
Key Findings
Commercial preservative solutions did not effectively maintain soil RNA quality compared to simple refrigeration
Unpreserved soil samples remained stable for ≥2 weeks at 2-8°C and ≥3 months at -80°C with no measurable degradation
Study identified 1,475 putative novel RNA viruses from 32 sequencing libraries, predominantly from microbe-associated phyla
Original Abstract
Soils represent one of the largest and most diverse reservoirs of microbial life on Earth, yet their associated RNA viruses remain underexplored compared to animal and aquatic systems. Viral discovery in soils has been further limited by technical hurdles, particularly difficulties in obtaining sufficient yields of high-quality RNA for sequencing. To address this, we evaluated a range of storage and preservation strategies, including the use of commercial preservative solutions and ultra-cold snap-freezing, followed by standardized RNA extraction, sequencing, and virus discovery pipelines. This work aimed to establish minimum sample storage requirements that maintain RNA integrity, generate sufficient RNA sequencing data, and subsequently enable reliable soil virome characterization. While no preservative solution proved effective, "neat" soil samples were stable at 2°C-8°C and -30°C for at least 2 weeks, and at -80°C for at least 3 months, with no measurable reduction in RNA quality, sequencing data, or viral abundance and diversity. From 32 resulting libraries, we identified 1,475 putative novel RNA viruses, with the majority belonging to the microbe-associated phylum