Genetic mechanism of non-targeted-site resistance to diquat in Spirodela polyrhiza

Understanding non-target-site resistance (NTSR) to herbicides represents a pressing challenge as NTSR is widespread in many weeds. Using the giant duckweed (Spirodela polyrhiza) as a model, we systematically investigated genetic and molecular mechanisms of diquat resistance, which can only be achieved via NTSR. Screening the diquat resistance among 138 genotypes suggested more than 8.5-fold resistance differences. Further experiments suggested that diquat uptake and antioxidant-related processes jointly contributed to diquat resistance in S. polyrhiza. Using a genome-wide association approach, we identified candidate genes that are associated with diquat resistance in S. polyrhiza, which includes a homolog of dienelactone hydrolase.