Glyphosate resistance in Ambrosia trifida: Part 1. Novel rapid cell death response to glyphosate

作者：Van Horn Christopher R; Moretti Marcelo L; Robertson Renae R; Segobye Kabelo; Weller Stephen C; Young Bryan G; Johnson William G; Schulz Burkhard; Green Amanda C; Jeffery Taylor; Lesperance Mackenzie A; Tardif Francois J; Sikkema Peter H; Hall J Christopher; McLean Michael D; Lawton Mark B; Sammons R Douglas; Wang Dafu; Westra Philip; Gaines Todd A

来源：Pest Management Science, 2018, 74(5): 1071-1078.

DOI：10.1002/ps.4567

• glyphosate resistance
• rapid response
• shikimate
• 5-enolypyruvyl shikimate 3-phosphate synthase
• target site
• giant ragweed

BACKGROUNDGlyphosate-resistant (GR) Ambrosia trifida is now present in the midwestern United States and in southwestern Ontario, Canada. Two distinct GR phenotypes are known, including a rapid response (GR RR) phenotype, which exhibits cell death within hours after treatment, and a non-rapid response (GR NRR) phenotype. The mechanisms of resistance in both GR RR and GR NRR remain unknown. Here, we present a description of the RR phenotype and an investigation of target-site mechanisms on multiple A. trifida accessions.
RESULTSGlyphosate resistance was confirmed in several accessions, and whole-plant levels of resistance ranged from 2.3- to 7.5-fold compared with glyphosate-susceptible (GS) accessions. The two GR phenotypes displayed similar levels of resistance, despite having dramatically different phenotypic responses to glyphosate. Glyphosate resistance was not associated with mutations in EPSPS sequence, increased EPSPS copy number, EPSPS quantity, or EPSPS activity.
CONCLUSIONThese encompassing results suggest that resistance to glyphosate in these GR RRA. trifida accessions is not conferred by a target-site resistance mechanism.

• 出版日期2018-5