Characterisation of turnip mosaic virus isolates reveals high genetic variability and occurrence of pathotype 1 in Brazil

Author(s)

Rodrigues, Leilane Karam ^[1] ; Chaves, Alexandre Levi Rodrigues ^[1] ; Kitajima, Elliot Watanabe ^[2] ; Calegario, Renata Faier ^[3] ; Brunelli, Katia Regiane ^[4] ; da Silva, Fabio Nascimento ^[5] ; Harakava, Ricardo ^[1] ; Walsh, John Anthony ^[6] ; Eiras, Marcelo ^[1]

Affiliation

^[1] Ctr Pesquisa Sanidade Vegetal, Inst Biol, Ave Conselheiro Rodrigues Alves 1252, BR-04014002 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, BR-13418400 Piracicaba, SP - Brazil

^[3] Univ Fed Parana, BR-80060000 Curitiba, PR - Brazil

^[4] Sakata Seed Sudamer, BR-12906840 Braganca Paulista, SP - Brazil

^[5] Univ Estado Santa Catarina, BR-88520000 Lages, SC - Brazil

^[6] Univ Warwick, Sch Life Sci, Coventry CV35 9EF, W Midlands - England

• Document type: Journal article
• Source: European Journal of Plant Pathology; v. 160, n. 4, p. 883-900, AUG 2021.
• Web of Science Citations: 1

Abstract

Turnip mosaic virus (TuMV) infects many plant species, being the only potyvirus able to infect brassicas. TuMV isolates have been classified into 12 pathotypes according to symptoms induced in lines of Brassica napus, and molecularly clustered into six lineages (basal-B, basal-BR, Asian-BR, world-B, Iranian and OMs). Despite being considered one of the most important viruses infecting brassicas worldwide, there is little information on this virus in the Neotropical region. Aiming to fill in this gap and advance knowledge on occurrence, genetic variability, and biological aspects of TuMV in Brazil, 40 isolates were identified and characterised. Five of these isolates were selected to determine their host range, sequence their genomes, and for phylogenetic, recombination and diversity analyses. Mechanical inoculations performed on plant species from 10 families showed differences in symptom expression among isolates. Inoculations of 13 TuMV isolates in B. napus lines revealed occurrence only of the pathotype 1. According to phylogenetic analyses of the coat protein, TuMV Brazilian isolates clustered into the groups: world-B (subgroups world-B2 and world-B3) and basal-BR. In the latter, there was a formation of a subclade named Brazilian subgroup composed by 31 Brazilian TuMV isolates. Intralineage and interlineage recombination events of world-B, basal-B and basal-BR suggest that Brazilian TuMV isolates had a European origin. Our diversity analysis suggest that a strong negative selection is acting on polyprotein coding region. We confirmed that Brazilian TuMV isolates showed high variability, which together with their ability to infect wild brassicas and to circumvent resistance genes highlight their genetic and epidemiological potential in causing damages in cultivated species of brassicas and other crops in Brazil. (AU)

• FAPESP's process: 18/17287-4 - Monitoring of the aphid fauna in Brassica spp. and its interaction in the dispersion of viruses in intensive cropping in the State of São Paulo
• Grantee: Alexandre Levi Rodrigues Chaves
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/22594-2 - Turnip mosaic virus: survey, identification, biological and molecular characterization, and epidemiological features of the Brazilian isolates that infect brassicas
• Grantee: Marcelo Eiras
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/50076-9 - Characterisation of Potyviruses infecting vegetable crops in Brazil and the stability of resistance identified in Europe to South American Potyviruses
• Grantee: Marcelo Eiras
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/18910-4 - Diversity of molecular pathogens (viruses and viroids) present in Brazil. Phase II. 2018
• Grantee: Elliot Watanabe Kitajima
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants