Biota Neotropica 20(2): e20190932, 2020 www.scielo.br/bn ISSN 1676-0611 (online edition) Inventory An annotated list of plant viruses and viroids described in Brazil (1926-2018) Elliot W. Kitajima1* 1Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Fitopatologia e Nematologia, 13418-900, Piracicaba, SP, Brasil *Corresponding author: Elliot W. Kitajima, e-mail: [email protected] KITAJIMA, E.W. An annotated list of plant viruses and viroids described in Brazil (1926-2018). Biota Neotropica 20(2): e20190932. https://doi.org/10.1590/1676-0611-BN-2019-0932. Abstract: A list of plant species, in alphabetical order by their scientific name, and the viruses found naturally infecting them in Brazilian territory, with some comments, was prepared . The production of such a list was based on a yearly catalog of publications on plant viruses collected by the author, from 1926 to 2018. Listed species of viruses were those recognized by the International Committee on Taxonomy of Viruses (ICTV), but also those characterized and still waiting official recognition, were included. Several cases of putative viral diseases were listed for historical reasons expecting to raise interest for their clarification. This list includes 345 plants species belonging to 74 families naturally infected by plant viruses in Brazil. Fabaceae and Asteraceae had most virus- infected species, respectively 49 and 36. Until 2018, a total of 213 plant virus and 6 viroid species belonging to 57 genera and 22 families and 6 orders, officially recognized by ICTV, were found naturally infecting these plants. Begomovirus and Potyvirus genera have most representatives, with 45 and 42 species, respectively. There are 59 characterized plant viruses, up to species level, described in Brazil waiting for the inclusion in the ICTV Master Species List. One hundred and thirteen viruses were identified up to genus level but still uncharacterized, while four putative isometric viruses and eleven presumptive viral diseases (“unidentified”) are included in the list. A reverse catalog, listing viruses and the plant species in which they were found is also included. Keywords: ICTV, plant species, virus species. Lista comentada de vírus e viróides de planta descritos no Brasil (1926-2018) Resumo: Esta publicação consiste em uma listagem de espécies de plantas, em ordem alfabética de seus nomes científicos, e dos vírus que foram encontrados naturalmente infetando-as em território brasileiro, com alguns comentários. O preparo de tal lista foi basedo nas publicações sobre vírus de plantas e as doenças que eles causam, colecionadas pelo autor de 1926 a 2018. Os vírus listados incluem aqueles já oficialmente reconhecidos pelo International Committee on Taxonomy of Viruses (ICTV), constantes do “Master Species List 2018”. Também estão incluídos vírus já caracterizados, aguardando oficialização pelo ICTV, e outros casos de possíveis viroses, cujo agente causal ainda não se acha adequadamente caracterizado. A listagem inclui 345 espécies de plantas, pertencentes a 74 famílias, que foram encontradas naturalmente infetadas por diferentes vírus. Fabáceas e Asteráceas foram as famílias que tiveram mais espécies infetadas por vírus, respectivamente 49 e 36. Até 2018, 213 espécies de vírus e 6 de viróides, pertencentes a 57 gêneros e 22 famílias e 6 ordens, oficialmente reconhecidas pelo ICTV, acham-se descritas no Brasil. Os gêneros Begomovirus e Potyvirus têm mais espécies representadas, com 45 e 42 respectivamente. Além das espécies identificadas e aceitas pelo ICTV, foram incluídas na lista 59 possíveis espécies que ainda aguardam oficialização, 113 vírus identificados a nível de gênero, quatro possíveis vírus isométricos e onze presumíveis viroses, de agentes etiológicos não confirmados. Foi incluída também uma lista reversa, com catalogação dos vírus e viróides descritos no Brasdil e suas respectivas plantas hospedeiras. Palavras-chave: ICTV, espécies de plantas, espécies de vírus. https://doi.org/10.1590/1676-0611-BN-2019-0932 http://www.scielo.br/bn 2 Biota Neotrop., 20(2): e20190932, 2020 Kitajima EW Introduction 2014). Plant viruses rarely cause dramatic and extensive damages to The concept that viruses are part of the bioma is still a controversial human activity as the pandemy of some human and animal viruses. On subject. Their chemical composition is akin of the cellular organisms. the contrary, their action is more subtle but inexorable and may cause They have DNA or RNA as their genome, proteins (protective, consistent and constant losses in the quality and quantity of most of enzymes) and lipid and glycid (in membrane bounded viruses). cultivated plants (vegetables, ornamentals, fruits, grains, industrial Being unable to replicate by themselves, viruses rely entirely on a crops, forestry, etc.). Thus a good deal of plant pathology research cellular host to do so, as a molecular parasite. As far as we know, is devoted to the study of plant viral diseases, especially because most of cellular organisms, from pro- to eucaryotes, have been found there are no economically available chemicals for curative treatment, infected by one or more viruses, some of them already integrated into as fungicides, antibiotics, nematicides, etc. efficient to control plant their genomes (Shors, 2008; Hull, 2014). Recent works, using next viruses. Usually, after identifying the causal virus, the management of generation sequencing (NGS) or high-throughput sequencing (HTS) the viral diseases concentrates on the use of genetically bred resistance technologies (Reuter et al., 2015), discovered a huge number of virus- varieties, cross-protection by mild strains, control of the vector, if any, like sequences in several environments (Walker et al., 2019). Their crop techniques (rotation, time and local for cultivation). Recently, proposition to incorporate them in the present official taxonomic use of genetic engineering by gene transference between different system seems unreal as discussed by van Regenmortel (2016), who organisms and even use of viral genes, have been tried to improve mentions that “the phenotypic and biological properties of members of resistance in some crops, against viral infection. But only few of new species taxa proposed on the basis of metagenomic data must be those transgenic plants are being used commercially, for they still face known before it becomes feasible to try to incorporate such hypothetical strong resistance by some sectors of the society (Hull, 2014; Rezende species in the current official system of virus classification”. & Kitajima, 2018). Because the intimate relationship of viruses in the biology and Brazil, being one of the most important world producer of animal evolution of cellular organisms, common sense and the ever-increasing and plant-derived commodities, has special interest in understanding evidences strongly suggest that viruses must be part of the living plant viral diseases to properly manage them. Presently about 100 world. Theories about the origin of viruses are speculative but we researchers and graduate students are involved in investigations can roughly list three main lines (Forterre, 2006; Garcia-Arenal et al., of many different plant viruses, to identify, characterize them and 2003; Koonin & Dolja, 2006; Lefeuvre et al., 2019; Krupovic et al., develop suitable management programs to reduce the hazards 2019; Simmonds, 2009): (1) involution of a parasitic prokaryote, which resulting from viral infection. The main problem is the vast extension gradually lost most of their genes, for the redundancy with those of of the country (8.5 square million kilometers) spanning from the host, keeping only those demanded for its own replication. Poxviruses equator to the subtropics, and presenting very diverse weather and soil and Mimiviruses are natural candidates for such possibility; (2) an conditions. The hot to milder climate favor the permanent presence aggroupment and reorganization of normal cell mRNAs containing of spontaneous vegetation, several of them potential host for a large information which led to their self-replication. The origin of most of number of crop affecting viruses, and worse, the continuous presence RNA viruses would fit in this scenario; (3) a relic of the precellular, of all kind of vectors (arthropods, fungus, nematodes). Also, the lack RNA world, when ribozymes permitted the self replication of RNA of a rigorous and efficient quarantine system results in the continuous molecules. The existence of some viroids could be explained by introduction of living part of plants and together, all sort of pests and this possibility. On the other hand, viruses, as molecular parasites, pathogens, including viruses. have been exerting important role in the evolution of living beings Historically, plant virology in Brazil began in two distinct centers throughout the time. It is a well documented fact that gene swapping in the years 1930’s. One, at the Instituto Biológico, at São Paulo (SP), between organisms of the same or different species can be mediated with A.A. Bittancourt and K.M. Silberschmidt, the last just arriving by viruses. Recent works have shown a large variety of viruses, whose from Germany. The second, at the Instituto Agronomico, Campinas- genome (integer or part) have been found integrated in the genome a IAC (SP) with A.S. Costa, with training at Princeton, US. Both groups large number of organisms of unrelated kingdom. Viral infection may developed important and pioneer researchs on plant viruses, mostly