Herbicide resistance in grass weeds: Epigenetic regulation matters too

Abstract

Although herbicides have been successfully used for controlling weeds, their continuous use has developed in the evolution of resistance to all major herbicide modes of action worldwide. Reports suggest that the members of Poaceae family are more prone to developing herbicide resistance than other families. In plants, epigenetic mechanisms play critical roles by increasing their stress-adaptive potential in a rapidly changing environment. Epigenetic mechanisms involve alteration of the expression of genetic elements, but without any changes in the DNA sequence. Although the possible roles of epigenetic mechanisms in contributing to survival and fitness under various stresses are well documented in model plants and crops, their contribution to herbicide resistance in weeds is still in its infancy. A few studies with herbicides have shown differential expression of DNA methyltransferases, histone methyltransferases and DNA demethylases in response to the herbicides; however, no further studies were conducted. In the case of herbicide stress, exploring how these epigenetic processes affect the gene expression pattern in individual plants subjected to recurrent selection would be exciting. Hence, our mini-review will focus on the potential contributions of epigenetic mechanisms to the adaptive responses of grass-weedy species to herbicide stress. A better understanding of these epigenetic changes will add novel perceptions to our knowledge of herbicide resistance evolution in weeds enabling the development of herbicides with novel targets.

Sequence Characterization of Extra-Chromosomal Circular DNA Content in Multiple Blackgrass (Alopecurus myosuroides) Populations

“…Perhaps the selective pressure and adaptative signatures that correspond to herbicide resistance have broader implications genomewide and further support mechanisms that provide resistance beyond metabolic genes. It has been proposed that plants that have rapidly evolved to a xenobiotic pressure also have a new disposition to withstand other abiotic stresses [67]. The compartmentalized genome architectures of the pathogens could also be organized in a way that these evolutionary signatures are more pronounced when compared with large plant genomes like blackgrass (3.2 Gb).…”

Current status of community resources and priorities for weed genomics research

“…Thus, regulatory elements of NTSR genes have been scrutinized to understand their role in NTSR mechanisms [ 113 ]. Similarly, epigenetic modifications have been hypothesized to play a role in NTSR, with much remaining to be explored [ 114 – 116 ]. Untargeted approaches such as genome-wide association, selective sweep scans, linkage mapping, RNA-sequencing, and metabolomic profiling have proven helpful to complement more specific biochemical- and chemo-characterization studies towards the elucidation of NTSR mechanisms as well as their regulation and evolution [ 47 , 117 – 124 ].…”

The International Weed Genomics Consortium: Community Resources for Weed Genomics Research

“…Thus, regulatory elements of NTSR genes have been scrutinized to understand their role in NTSR mechanisms [104]. Similarly, epigenetic modifications have been hypothesized to play a role in NTSR, with much remaining to be explored [105][106][107]. Untargeted approaches such as genome-wide association, selective sweep scans, linkage mapping, RNA-sequencing, and metabolomic profiling have proven helpful to complement more specific biochemical-and chemocharacterization studies towards the elucidation of NTSR mechanisms as well as their regulation and evolution [60,[108][109][110][111][112][113][114][115].…”