Awaking the dormant virome in the rhizosphere

Area of Science:

• Microbiology
• Environmental Science
• Ecology

Background:

• The rhizosphere, crucial for plant health, harbors diverse viruses (viromes) with poorly understood diversity drivers.
• Viruses interact with bacterial hosts via lytic or lysogenic cycles; dormant viruses (prophages) can be reactivated by environmental perturbations.
• Dormant viruses are widespread, with 22%-68% of soil bacteria potentially harboring them, suggesting viral blooms are key to soil viral diversity.

Purpose of the Study:

• To investigate the viral bloom response in rhizospheric viromes under different soil perturbation conditions.
• To characterize the functional genes within perturbed viromes and assess their impact on pristine soil microbiomes.
• To understand the role of viromes in soil ecological memory and eco-evolutionary processes.

Main Methods:

• Rhizospheric viromes were exposed to earthworms, herbicides, and antibiotic pollutants.
• Viromes were screened for specific functional genes.
• Perturbed viromes were used as inoculants in soil microcosm incubations to assess their impact on native microbiomes.

Main Results:

• Perturbations altered virome composition, with herbicide and antibiotic pollutants causing similar viral community shifts.
• Earthworm exposure increased viral populations containing plant-beneficial genes.
• Inoculation of perturbed viromes into soil microcosms altered microbiome diversity, indicating a role in soil ecological memory.

Conclusions:

• Rhizospheric viromes are dynamic and responsive to environmental changes.
• Viruses play an active role in the rhizosphere, influencing microbial community structure and function.
• Understanding virome dynamics is essential for managing soil microbial processes and promoting sustainable agriculture.