Geminivirus-Encoded Proteins: Not All Positional Homologs Are Made Equal

Abstract

Geminiviruses are insect-transmitted plant viruses with circular, single-stranded (ss)DNA genomes that cause devastating diseases in major crops worldwide. The family Geminiviridae comprises more than 450 species divided in nine genera, based on genome organization, host range, and insect vector: Begomovirus, Mastrevirus, Curtovirus, Becurtovirus, Topocuvirus, Turncurtovirus, Capulavirus, Gablovirus, and Eragrovirus (Zerbini et al., 2017). The most diverse genus in this family is Begomovirus, which to date includes 409 different species (reviewed in Zhao et al., 2019). Begomoviruses can be further subdivided in monopartite, with one-molecule genomes, and bipartite, with two-molecule genomes (Figure 1A). Regardless of whether they are mono- or bi-partite, the size of each genomic DNA molecule is ∼3 kb. Apart from the obvious economic and practical interest