A Target-Site Point Mutation in Henbit (Lamium amplexicaule) Confers High-Level Resistance to ALS-Inhibitors

作者：Varanasi Vijay K; Godar Amar S; Peterson Dallas E; Shoup Doug; Jugulam Mithila^*

来源：Weed Science, 2016, 64(2): 231-239.

DOI：10.1614/WS-D-15-00152.1

• 5 '- and 3 '- RACE
• ALS inhibitors
• herbicide resistance
• winter annual weed

Henbit is a facultative broadleaf winter annual in the Lamiaceae family. Acetolactate synthase (ALS) inhibitors are primarily used to control a broad spectrum of weeds, including henbit. During 2012 to 2013, field applications of ALS-inhibiting herbicides were ineffective in controlling a henbit population from Marion County, KS (MCK). To confirm field-evolved resistance to ALS inhibitors, response of MCK henbit and a known susceptible henbit population from Kansas (DPS) to varying doses of three different ALS inhibitors were examined: chlorsulfuron, imazamox, and propoxycarbazone. Results of the dose-response experiments suggest that the MCK population is highly resistant to chlorsulfuron (resistance index [R/S] > 1,000) and propoxycarbazone (R/S = 331) but is susceptible to imazamox. A full-length ALS gene sequence obtained using the 5'- and 3'- rapid amplification of complementary DNA ends approach revealed a Pro(197) to Arg point mutation (a common mutation that confers resistance to sulfonylurea herbicides, e.g., chlorsulfuron) in the MCK henbit. No other known resistance-conferring mutations were found in the study. Evolved resistance to major classes of ALS inhibitors in the MCK henbit will reduce herbicide options for its control. To our knowledge, this is the first case of evolution of herbicide resistance in henbit.

• 出版日期2016-6