Pest Management Science (2017) 73, 2227-2235

Martin Laforest, Brahim Soufiane, Marie-Josée Simard, Kristen Obeid, Eric Page and Robert E. Nurse (2017)
Acetyl-CoA carboxylase overexpression in herbicide-resistant large crabgrass (Digitaria sanguinalis)
Pest Management Science 73 (11), 2227-2235
Abstract:
BACKGROUND
The occurrence of herbicide-resistant weed biotypes is increasing and this report of an acetyl-CoA carboxylase (ACCase) inhibitor-resistant Digitaria sanguinalis L. Scop. from southwestern Ontario is another example. The identified weed escaped control in an onion and carrot rotation in which graminicides were used for several consecutive years. Our goal was to characterize the level and mechanism of resistance of the biotype.
RESULTS
The biotype was resistant to all five ACCase inhibitor herbicides tested. Gene-expression profiling was performed because none of the mutations known to confer resistance in the ACCase gene were detected. RNASeq and quantitative reverse-transcriptase PCR (qRT-PCR) results indicated that transcription of ACCase was 3.4–9.3 times higher in the resistant biotype than the susceptible biotype. ACCase gene copy number was determined by qPCR to be five to seven times higher in the resistant compared with the susceptible biotype. ACCase gene overexpression was directly related to the increase of the ACCase gene copy number.
CONCLUSION
Our results are consistent with the hypothesis that overexpression of the herbicide target gene ACCase confers resistance to the herbicide. This is the first reported case of target gene duplication conferring resistance to a herbicide other than glyphosate.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Martin Laforest, Marie-Josée Simard, Robert E. Nurse

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Digitaria sanguinalis (weed)		Canada (east)