CYP72A15 confers resistance against penoxsulam to Echinochloa phyllopogon.

As the weed Echinochloa phyllopogon has rapidly developed multi- and cross-resistance to several herbicides, we aimed to determine the mechanism underlying penoxsulam resistance in weeds. There was no target mutation in the tested population, and P450 enzyme activity was significantly higher in the penoxsulam-treated resistant population, confirming that non-target-site resistance was dominant. The antioxidant enzyme activity of the resistant population was higher than that of the sensitive population following the application of the penoxsulam and cleared H2O2 faster. The antioxidant enzyme system of the sensitive population was inhibited in the early stage of the stress and the malondialdehyde content was increased, leading to severe cellular damage. Transcriptome sequencing indicated upregulated expression of metabolic genes related to resistance including CYP709B2, CYP71C4, CYP72A15, and AKR4C10 in resistant versus sensitive populations. Overexpression of CYP72A15 in Arabidopsis thaliana induced significant resistance to penoxsulam, bensulfuron-methyl, and quinclorac. Transgenic Oryza sativa once again demonstrated the important role of CYP72A15 in E. phyllopogon herbicide resistance. The current study highlights the role of CYP450 family enzymes in the herbicide resistance of weeds.