Cytochrome P450CYP81A104 in Eleusine indica confers resistance to multiherbicide with different modes of action

Abstract BACKGROUND Developing herbicide‐resistant (HR) crop cultivars is an efficient way to control weeds and minimize crop yield losses. However, widespread and long‐term herbicide application has led to the evolution of resistant weeds. Here, we established a resistant (R) E. indica population, collected from imidazolinone‐resistant rice cultivar fields. RESULTS The R population evolved 4.5‐fold resistance to imazamox. Acetolactate synthase (ALS) gene sequencing and ALS activity assays excluded the effect of target‐site resistance in this population. P450 inhibitor malathion pretreatment significantly reversed resistance to imazamox. RNA sequencing showed that a P450 gene CYP81A104 was expressed higher in R versus susceptible (S) plants. Arabidopsis overexpressing CYP81A104 showed resistance to ALS inhibitors (imazamox, tribenuron‐methyl, penoxsulam and flucarbazone‐sodium), PSII inhibitor (bentazone), hydroxyphenyl pyruvate dioxygenase inhibitor (mesotrione) and auxin mimics (MCPA), which was generally consistent with the results presented in the R population. CONCLUSION This study confirmed that the CYP81A104 gene endowed resistance to multiherbicides with different modes‐of‐action. Our findings provide an insight into the molecular characteristics of resistance and contribute to formulating an appropriate strategy for weed management in HR crops. © 2024 Society of Chemical Industry.