Loss-of-function in GIGANTEA confers resistance to PPO-inhibiting herbicide tiafenacil through transcriptional activation of antioxidant genes in Arabidopsis

Abstract Herbicides play a crucial role in maintaining crop productivity by reducing competition between weeds and crops. Protoporphyrinogen oxidase (PPO)-inhibiting herbicides trigger the photooxidative damage that destroys cell membranes. Tiafenacil is recently developed pyrimidinedione-type PPO-inhibiting herbicide has low IC 50 values plants less toxic humans compared to other PPO inhibitors. Previous reports confirmed mutations Arabidopsis circadian clock-controlled gene GIGANTEA ( GI ) were insensitive phytooxidants, including chloroplast biogenesis inhibitors herbicides. Here, we examined whether regulates resistance tiafenacil. Both gi mutant alleles, gi-1 gi-2 , resistant tiafenacil with survival rates of 97% 83%, respectively, under 1 µM treatments, while 56% wild-type GI-overexpressing (GI-OX) survived. mutants tiafenacil-induced inhibition photosystem efficiency alleviated damage. The showed significant increases transcriptional expressions enzyme activities antioxidants GI-OX. Moreover, loss-of-function enhanced tiafenacil-containing commercial Terrad’or Plus ® . Collectively, based on our results together previous reports, confer different MoAs would be molecular target for non-target-site strategies develop herbicide-resistant