Viruses roam the wheat phyllosphere

Abstract

The phyllosphere comprises all the above-ground sections of plants. This niche is colonised by complex microbial communities, including algae, fungi, archaea, and bacteria. They are known to induce plant growth and promote health or act as causative agents of plant diseases. It is thought that the most abundant organisms are phyllobacteria2, with an estimate between 106 to 107 cells per cm2. Viruses are highly abundant across many environments, often outnumbering bacteria 10 to 19. However, not much is known about their abundance and composition in the phyllosphere, a harsh environment for viruses due to environmental variability and high UV exposure. To investigate this niche in detail, we extracted, sequenced and analysed phyllosphere virome. Using leaf samples from winter wheat (Triticum aestivum), we identified a total of 876 viral populations (vOTUs), mostly belonging to the Caudovirales order. Most of these were predicted to be lytic. Remarkably, 810 of these viral populations correspond to new viral species with no matches to known sequences. We estimate a minimum of 2.0x10^6 viral particles per leaf. Overall, these findings suggest that the phyllosphere ecosystem harbours an abundant and active community of novel viruses that play essential roles in shaping this habitat.

Divergent endophytic viromes and phage genome repertoires among banana (Musa) species

“…Moreover, interactions between viruses, microbes, and hosts can create complex dynamics (Knief et al, 2012;Van Belleghem et al, 2018;Rodriguez et al, 2019) in which viruses may serve as resident regulators impacting hosts or their endophytic populations to alter net secondary metabolite biosynthesis (Roossinck et al, 2015;Seo and Kweon, 2019). Using whole-genome shotgun genomics (WGS) can reveal hidden viral diversity within plants (Forero-Junco et al, 2021). However, most endophyte WGS studies focus on bacterial or fungal communities, with limited analysis of DNA viruses (Regalado et al, 2020;Akinola et al, 2021;Soto-Giron et al, 2021;Fadiji et al, 2021a,b).…”