Extent, cause and regulation of metabolic flufenacet resistance in ryegrass (Lolium spp.)

• Applicant: Rebecka Duecker, Ph.D.
• Subject Area: Plant Breeding and Plant Pathology
• Term: from 2023 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 521767580

Herbicide resistance is an increasing problem in conventional agriculture, however, metabolic resistance in particular is poorly understood. Especially ryegrasses (Lolium spp.) are characterized by their ability to evolve metabolic resistance to a variety of different herbicides. In a previous RNA-Seq study, we identified and validated an up-regulated glutathione transferase in flufenacet-resistant ryegrass from England, France and the USA. However, it is not yet known how this gene is regulated. The Lolium multiflorum genome recently assembled and annotated at Michigan State University is an excellent basis for bioinformatic investigation of this question. Therefore, a re-alignment of the sequences (reads) from the RNA-Seq study with the new genome is planned in frame of this study. Subsequently, the promoter region of the candidate gene will be examined with deep and machine learning approaches to identify polymorphisms which may drive differential expression of the validated glutathione transferase and co-expressed genes. This analysis will be combined with a co-expression network analysis. In a second approach, ryegrass field populations and varieties of ryegrass will be characterized. Resistant survivors will be crossed with sensitive individuals of different agronomically relevant ryegrass species. This approach will be combined with a population genetics study using genotyping-by-sequencing to investigate the spread and evolution of resistance and the potential role of ryegrass varieties in the spreading resistance. In this way, this study can i) contribute to the understanding of metabolic herbicide resistance and the co-regulation of resistance genes, ii) allow a better understanding of the spread of resistance and offer preventive measures based on this information and, and iii) provide a basis for the development of genetic markers for metabolic herbicide resistance.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professor Eric Patterson, Ph.D.