Comparative analysis of bacterial populations in sulfonylurea-sensitive and -resistant weeds: insights into community composition and catabolic gene dynamics

This study aimed to compare the impact of iodosulfuron-methyl-sodium and an iodosulfuron-based herbicidal ionic liquid (HIL) on the microbiomes constituting the epiphytes and endophytes of cornflower (Centaurea cyanus L.). The experiment involved biotypes of cornflower susceptible and resistant to acetolactate synthase inhibition, examining potential bacterial involvement in sulfonylurea herbicide detoxification. We focused on microbial communities present on the surface and in the plant tissues of roots and shoots. The research included the synthesis and physicochemical analysis of a novel HIL, evaluation of shifts in bacterial community composition, analysis of the presence of catabolic genes associated with sulfonylurea herbicide degradation and determination of their abundance in all experimental variants. Overall, for the susceptible biotype, the biodiversity of the root microbiome was higher compared to shoot microbiome; however, both decreased notably after herbicide or HIL applications. The herbicide-resistant biotype showed lower degree of biodiversity changes, but shifts in community composition occurred, particularly in case of HIL treatment.