The blackgrass genome reveals patterns of divergent evolution of non-target site resistance to herbicides

Abstract

SummaryGlobally, weedy plants result in more crop yield loss than plant pathogens and insect pests combined. Much of the success of weeds rests with their ability to rapidly adapt in the face of human-mediated environmental management and change. The evolution of resistance to herbicides is an emblematic example of this rapid adaptation. Here, we focus on Alopecurus myosuroides (blackgrass), the most impactful agricultural weed in Europe. To gain insights into the evolutionary history and genomic mechanisms underlying adaptation in blackgrass, we assembled and annotated its large, complex genome. We show that non-target site herbicide resistance is oligogenic and likely evolves from standing genetic variation. We present evidence for divergent selection of resistance at the level of the genome in wild, evolved populations, though at the transcriptional level, resistance mechanisms are underpinned by similar patterns of up-regulation of stress- and defence-responsive gene families. These gene families are expanded in the blackgrass genome, suggesting that the large, duplicated, and dynamic genome plays a role in enabling rapid adaptation in blackgrass. These observations have wide significance for understanding rapid plant adaptation in novel stressful environments.

The genome ofLolium multiflorumreveals the genetic architecture of paraquat resistance

“…Obtaining a contiguous genome is a crucial component of the assembly effort (Lee et al, 2016) that allows researchers to better understand the genomic context in which genes or variants of interest occur. The L. multiflorum genome assembled here had 90% of the DNA content placed on 7 chromosomes (N 50 =363 Mb), with 93% completeness, which is comparable to other high-quality assemblies (Cai et al, 2021, Benson et al, 2023.…”

On Disease Configurations, Black-Grass Blowback, and Probiotic Pest Management

“…Furthermore, black-grass’s genetic development pathways and its high seeding rate make it particularly quick to develop resistance to selective herbicides (Cai et al. 2021 ). As excess chemical applications select for more resistant weeds, the emergence of herbicide resistance is correlated with the intensity of historical chemical control programs (Hicks et al.…”