First case of triple resistance to EPSPS, ALS, and synthetic auxin herbicides in Bassia scoparia (L.) Voss in Europe

Bassia scoparia (L.) Voss has evolved resistance to five herbicide modes of action (MoAs) worldwide, including multiple resistance to up to four MoAs. Seeds were collected from a putatively resistant B. scoparia population (GUI-R) that survived successive herbicide applications of synthetic auxins,...

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Detalles Bibliográficos
Autores: Mora, Germán, Gil-Monreal, Miriam, Osuna, Maria Dolores, Vijayarajan, Vijaya Bhaskar Alwarnaidu, Montull, José María, Llenes, Josep María, Recasens i Guinjuan, Jordi, Cirujeda, Alicia, Marí, Ana Isabel, Torra Farré, Joel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10459.1/468465
Acceso en línea:https://doi.org/10.1016/j.pestbp.2025.106529
https://hdl.handle.net/10459.1/468465
Access Level:acceso abierto
Palabra clave:ALS mutations
Bassia scoparia
EPSPS inhibitor resistance
Descripción
Sumario:Bassia scoparia (L.) Voss has evolved resistance to five herbicide modes of action (MoAs) worldwide, including multiple resistance to up to four MoAs. Seeds were collected from a putatively resistant B. scoparia population (GUI-R) that survived successive herbicide applications of synthetic auxins, acetolactate synthase (ALS), and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibitors in a no-till winter cereal field in Catalonia, Spain, in 2022, to assess resistance levels and mechanisms. Dose-response assays confirmed that GUI-R was 2-, 340-, 42.7-, and 60-fold more resistant to glyphosate, thifensulfuron, MCPA, and 2,4-D, respectively, based on plant weight, and 3.2-, 123-, 57.9-, and 32-fold more resistant based on plant survival. GUI-R showed cross-resistance to imazamox (46 % survival), but not to dicamba or fluroxypyr (100 % mortality), at the label rate. Preliminary studies using malathion pre-treatment, a cytochrome P450 inhibitor, reversed 2,4-D resistance in GUI-R at the label rate, resulting in a 97 % reduction in biomass. Molecular studies revealed that GUI-R has 4.9 additional copies of the EPSPS:ALS gene, with no known mutations and less shikimate accumulation than the susceptible population. ALS gene sequencing identified the Pro197Ser, Pro197Leu, and Trp574Leu mutations, along with a combined Pro197Ser + Trp574Leu mutation. In conclusion, EPSPS gene amplification and ALS mutations confer target-site resistance to glyphosate, thifensulfuron and imazamox in GUI-R. Resistance to 2,4-D and MCPA is probably driven by P450-mediated non-target-site resistance and further research is necessary to confirm mechanisms. This biotype represents the first case of glyphosate resistance in Europe for the species, as well as the first triple resistance.