Saint-Jean-sur-Richelieu R&D Centre, Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, QC, Canada.
Department of Plant, Soil, & Microbial Sciences, Michigan State University, East Lansing, MI, USA.
Pest Manag Sci. 2021 Nov;77(11):4993-5000. doi: 10.1002/ps.6541. Epub 2021 Jul 12.
Poa annua is a pervasive grassy, self-pollinating, weed that has evolved resistance to 10 different herbicide modes-of-action, third most of all weed species. We investigated constitutive overexpression of genes associated with non-target site resistance (NTSR) in POAAN-R3 and the response of those genes when treated with trifloxysulfuron despite the biotype having a known target site mutation in acetolactate synthase (ALS).
Despite having an ALS target site mutation, POAAN-R3 still had a transcriptomic response to herbicide application that differed from a susceptible biotype. We observed differential expression of genes associated with transmembrane transport and oxidation-reduction activities, with differences being most pronounced prior to herbicide treatment.
In the P. annua biotype we studied with confirmed target site resistance to ALS inhibitors, we also observed constitutive expression of genes regulating transmembrane transport, as well as differential expression of genes associated with oxidative stress after treatment with trifloxysulfuron. This accumulation of mechanisms, in addition to the manifestation of target site resistance, could potentially increase the chance of survival when plants are challenged by different modes of action.
早熟禾是一种普遍存在的草状、自花授粉、杂草，已进化出对 10 种不同除草剂作用模式的抗性，是所有杂草物种中第三多的。我们研究了与非靶标位点抗性（NTSR）相关的基因在 POAAN-R3 中的组成型过表达，以及这些基因在使用三氟啶磺隆时的反应，尽管该生物型在乙酰乳酸合酶（ALS）中具有已知的靶标位点突变。
尽管 POAAN-R3 具有 ALS 靶标位点突变，但它对除草剂的应用仍有转录组反应，与敏感生物型不同。我们观察到与跨膜转运和氧化还原活性相关的基因的差异表达，在除草剂处理前差异最为明显。
在我们研究的具有 ALS 抑制剂靶标抗性的早熟禾生物型中，我们还观察到调节跨膜转运的基因的组成型表达，以及在用三氟啶磺隆处理后与氧化应激相关的基因的差异表达。除了靶标抗性的表现外，这种机制的积累可能会增加植物受到不同作用模式挑战时的生存机会。
