FIG 1.

(A) Phylogram of virus composition across the 1000 Plant Transcriptomes Initiative (1KP) samples. Plant-associated virus abundance was summarized for each plant species and normalized using a Box-Cox transformation. The height of each bar represents the percentage of virus reads detected in each plant species (after the removal of host reads). Plant clades are labeled and differentiated by shades of gray. The 1KP ASTRAL tree was used as the basis for this tree (29). Clade and abundance annotations were added using the Interactive Tree of Life (iTOL) Web-based tool (108). (B) The phytovirosphere across the Plantae and Phaeophyceae. A schematic tree of the evolution of major plant groups. Each bar represents the number of total viruses formally or likely associated with each host group and is colored by virus genome composition. The total number of viruses for each plant group plus those found in this study is also shown at the end of each bar. The Virus-Host (79) and NCBI virus databases (109) combined with literature searches were used to obtain virus counts. Lineage branches are not drawn to scale. To our knowledge, no viruses have been found in the glaucophytes. Plant and alga images were obtained from BioRender.com or drawn in Adobe Illustrator (https://www.adobe.com). *, Transcriptome scaffolds from libraries belonging to these host groups shared homology to virus RdRps and were partially analyzed but not assembled or deposited in GenBank (16).