Terrestrial arthropods and plants have coevolved for over 450 million years. Ensuing from their intimate coexistence, in addition to herbivory and pollination, the plant-arthropod partnership exhibits a number of complex connections amongst which viruses are both players and witnesses. Some plant-infecting viruses replicate in the arthropods that assist them in their transmission, whereas others that only infect plants retain genetic hallmarks exposing a close phylogeny with some non-plant-infecting viruses. The exploration into the current viral biodiversity has revealed viruses typifying these two groups rendering models that help to understand the virus-host co-evolution processes.
Viruses assigned to the recently created family Kitaviridae have bi-, three- and tetra-partite single-stranded positive RNA genomes and belong to genera Cilevirus, Higrevirus and Blunervirus, respectively. Citrus leprosis virus C (CiLV-C), best-studied kitavirid, is transmitted by phytophagous false-spider mites of genus Brevipalpus in a persistent manner, while contrasting evidence hampers a conclusive definition about its propagation in the mite cells. CiLV-C seems to have a narrow range of natural plant hosts, in which the viral infection is restricted to cells around the mite feeding regions. Non-systemic infection of plants seems to be a common but not a general feature of kitavirids. A recently discovered blunervirus systemically infects tea plants in China, seeming to overcome limitations of the other family members unable to spread through the plants. Phylogeny using two proteins of kitavirids, i.e. RdRp and the orphan protein P24, reveal not only the relationship amongst them but also with an increasing number of arthropod-infecting viruses collectively known as negeviruses.
Different from kitavirids, negeviruses show monopartite ss(+)RNA genomes, are often found in insects, and their taxonomic classification is not accurately defined. Besides the RdRp and P24, they commonly encode a putative glycoprotein with structural features also conserved in a cognate protein encoded by kitavirids. This evidence suggests that current nege-like viruses and kitavirids have arisen from a hypothetical common ancestral arthropod-infecting virus, but the evolutionary pathways leading to their host expansion are still poorly explored. In this sense, the characterization of the binary movement block of the higrevirus hibiscus green spot virus has shed light on the origin of plant virus transport systems and the putative mechanisms allowing their acquisition from plants or other plant-infecting viruses.
The Research Topic aims to explore the border between kitavirids and nege-related viruses expanding the opportunities to understand evolutionary processes involved in the speciation of current known viruses. We welcome Original Research, Opinions, Perspectives, and Review articles highlighting the diversity of kitavirids and nege-related viruses and their phylogenetic relationships, virus-vector and virus-host interactions, characterization of viral proteins, preferentially emphasizing their parallels and differences from an evolutionary point of view.
Terrestrial arthropods and plants have coevolved for over 450 million years. Ensuing from their intimate coexistence, in addition to herbivory and pollination, the plant-arthropod partnership exhibits a number of complex connections amongst which viruses are both players and witnesses. Some plant-infecting viruses replicate in the arthropods that assist them in their transmission, whereas others that only infect plants retain genetic hallmarks exposing a close phylogeny with some non-plant-infecting viruses. The exploration into the current viral biodiversity has revealed viruses typifying these two groups rendering models that help to understand the virus-host co-evolution processes.
Viruses assigned to the recently created family Kitaviridae have bi-, three- and tetra-partite single-stranded positive RNA genomes and belong to genera Cilevirus, Higrevirus and Blunervirus, respectively. Citrus leprosis virus C (CiLV-C), best-studied kitavirid, is transmitted by phytophagous false-spider mites of genus Brevipalpus in a persistent manner, while contrasting evidence hampers a conclusive definition about its propagation in the mite cells. CiLV-C seems to have a narrow range of natural plant hosts, in which the viral infection is restricted to cells around the mite feeding regions. Non-systemic infection of plants seems to be a common but not a general feature of kitavirids. A recently discovered blunervirus systemically infects tea plants in China, seeming to overcome limitations of the other family members unable to spread through the plants. Phylogeny using two proteins of kitavirids, i.e. RdRp and the orphan protein P24, reveal not only the relationship amongst them but also with an increasing number of arthropod-infecting viruses collectively known as negeviruses.
Different from kitavirids, negeviruses show monopartite ss(+)RNA genomes, are often found in insects, and their taxonomic classification is not accurately defined. Besides the RdRp and P24, they commonly encode a putative glycoprotein with structural features also conserved in a cognate protein encoded by kitavirids. This evidence suggests that current nege-like viruses and kitavirids have arisen from a hypothetical common ancestral arthropod-infecting virus, but the evolutionary pathways leading to their host expansion are still poorly explored. In this sense, the characterization of the binary movement block of the higrevirus hibiscus green spot virus has shed light on the origin of plant virus transport systems and the putative mechanisms allowing their acquisition from plants or other plant-infecting viruses.
The Research Topic aims to explore the border between kitavirids and nege-related viruses expanding the opportunities to understand evolutionary processes involved in the speciation of current known viruses. We welcome Original Research, Opinions, Perspectives, and Review articles highlighting the diversity of kitavirids and nege-related viruses and their phylogenetic relationships, virus-vector and virus-host interactions, characterization of viral proteins, preferentially emphasizing their parallels and differences from an evolutionary point of view.
