Figure 2.

Chromoviruses in plants: structural organization of PpatensLTR1 from Physcomitrella patens (A); a schematic evolutionary tree of plants chromoviruses reconstructed from a multiple alignment of reverse transcriptase DNA fragment (B); and distribution of various chromovirus clades (C). Abbreviations: 5′ and 3′ LTRs—5′ and 3′ long terminal repeats; PR—aspartyl protease, RT—reverse transcriptase, RNaseH—ribonuclease H, Int—integrase, chromo—chromodomains. The plant phylogenetic tree is after Bowman et al.⁴⁰ with minor modifications. The divergence time estimations are shown after Hedges.⁴¹ For a more detailed evolutionary tree of plant chromoviruses, see Novikova et al.⁴²