Widespread distribution of resistance to triazole fungicides in Brazilian populations of the wheat blast pathogen

Autor(es):Mostrar menos -

Poloni, Nadia Maria ^[1] ; Carvalho, Giselle ^[1] ; Nunes Campos Vicentini, Samara ^[1] ; Francis Dorigan, Adriano ^[1] ; Nunes Maciel, Joao Leodato ^[2] ; McDonald, Bruce A. ^[3] ; Intra Moreira, Silvino ^[1] ; Hawkins, Nichola ^[4] ; Fraaije, Bart A. ^{[4, 5]} ; Kelly, Diane E. ^[6] ; Kelly, Steven L. ^[6] ; Ceresini, Paulo C. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, UNESP, Dept Crop Protect Agr Engn & Soil, Dept Fitossanidade Engn Rural & Solos, Sao Paulo - Brazil

^[2] EMBRAPA Wheat, Brazilian Agr Res Corp, Passo Fundo, RS - Brazil

^[3] Swiss Fed Inst Technol, Inst Integrat Biol, Plant Pathol Grp, Zurich - Switzerland

^[4] Rothamsted Res, Biointeract & Crop Protect, Harpenden, Herts - England

^[5] Natl Inst Agr Bot NIAB, Cambridge - England

^[6] Swansea Univ, Sch Med, Inst Life Sci, Ctr Cytochrome P450 Biodivers, Swansea, W Glam - Wales

• Tipo de documento: Artigo Científico
• Fonte: PLANT PATHOLOGY; v. 70, n. 2 OCT 2020.
• Citações Web of Science: 0

Resumo

Fungicides have not been effective in controlling the wheat blast disease in Brazil. An earlier analysis of 179 isolates of Pyricularia oryzae Triticum lineage (PoTl) sampled from wheat fields across six populations in central-southern Brazil during 2012 discovered a high level of resistance to strobilurin fungicides. Here we analysed azole resistance in the same strains based on EC50 measurements for tebuconazole and epoxiconazole. All six Brazilian populations of PoTl exhibited high resistance to both azoles, with in vitro EC50 values that were at least 35 to 50 times higher than the recommended field doses. We sequenced the CYP51A and CYP51B genes to determine if they were likely to play a role in the observed azole resistance. Although we found five distinct haplotypes in PoTl carrying four nonsynonymous substitutions in CYP51A, none of these substitutions were correlated with elevated EC50. CYP51B was sequenced for nine PoTl isolates, three each representing low, medium, and high tebuconazole EC50. Both PoTl CYP51A and CYP51B could complement yeast CYP51 function. All PoTl CYP51A-expressing yeast transformants were less sensitive to triazoles than the PoTl CYP51B ones. Transformants expressing PoTl CYP51A haplotype H1 carrying the R158K substitution were not more resistant than those expressing PoTl CYP51A haplotype H5, which is synonymous to haplotype H6, found in triazole-sensitive P. oryzae Oryza isolates from rice blast. Therefore, the reduced triazole sensitivity of wheat blast isolates compared to rice blast isolates appears to be associated with a non-target-site related resistance mechanism acquired after higher exposure to triazoles. (AU)

• Processo FAPESP: 13/10655-4 - Desvendando a origem local da brusone do trigo (Magnaporthe oryzae) no Centro Sul do Brasil e evidências da emergência de resistência a fungicidas estrobilurinas em populações do patógeno
• Beneficiário: Paulo Cezar Ceresini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/12509-1 - Novas ferramentas de monitoramento de doenças e de resistência a fungicidas, em tempo real, para promover plataforma inteligente e sustentável de proteção de culturas no Brasil
• Beneficiário: Silvino Intra Moreira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/50456-1 - Compreendendo a evolução para resistência a fungicidas em populações de campo do patógeno da brusone do trigo no Brasil: é possível aprender lições para o futuro manejo da doença?
• Beneficiário: Paulo Cezar Ceresini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/21197-0 - Novas ferramentas de monitoramento de doenças e de resistência a fungicidas, em tempo real, para promover plataforma inteligente e sustentável de proteção de culturas no Brasil
• Beneficiário: Paulo Cezar Ceresini
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/10453-8 - A emergência de Pyricularia tritici sp. Nov. como patógeno da brusone do trigo no Brasil: especiação simpátrica inferida por filogenia multiloci, espectro de patogenicidade e evolução de genes de virulência
• Beneficiário: Paulo Cezar Ceresini
• Modalidade de apoio: Auxílio à Pesquisa - Regular