Mapping non-targeted-site resistance to herbicides in Spirodela polyrhiza (MapNTSR)

• Applicant: Professor Dr. Shuqing Xu, Ph.D.
• Subject Area: Plant Genetics and Genomics ; Evolution and Systematics of Plants and Fungi
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 427577435

Adaptive evolution of plants to environmental change – either natural or human-mediated - shaped the global biodiversity and can profoundly affect the development of human societies. A classic example is the rapid increase of herbicide resistance in weeds, which threatens worldwide crop yields. The mechanisms of herbicide resistance mechanisms are classified into two types: target-site resistance (TSR), which is caused by changes in the herbicide target protein, and non-target site resistance (NTSR), which includes all other mechanisms. Recent studies suggested that NTSRs arises from standing genetic variations that are associated with adaptation to natural stresses. However, due to the lack of a suitable model system in which the detailed molecular mechanisms and ecological functions of NTSR can be characterized, this hypothesis remains largely unexamined. Here, we will use the giant duckweed, Spirodela polyrhiza, as a model system to investigate the resistance to glyphosate and diquat, two extensively used herbicides, which are considered to be predominantly caused by NTSR. We will combine a genome-wide association approach and gene co-expression network analyses to identify the genetic basis underlying the resistance. Furthermore, using a state-of-the-art genome editing tool (CRISPR/Cas9), we will manipulate the identified candidate genes and investigate the underlying molecular mechanisms of the NTSR in the giant duckweed. Additionally, we will evaluate to what extent changes of the genes involved in NTSR affect the resistance to natural stresses. This integrative study will bridge a knowledge gap in understanding the molecular mechanisms, processes and consequences of adaptation to herbicides and facilitate the development of new strategies to improve weed management.

• DFG Programme: Research Grants