Metabolic Resistance to Acetyl-CoA Carboxylase-Inhibiting Herbicide Cyhalofop-Butyl in a Chinese Echinochloa crus-galli Population

Abstract

A population of Echinochloa crus-galli (L.) P. Beauv obtained from direct-seeding rice fields in Jiangxi Province, China, exhibited high resistance levels (13.5-fold) to the acetyl-CoA carboxylase (ACCase)-inhibiting herbicide cyhalofop-butyl. Compared with the susceptible (S) population, this resistant (R) population evolved a cross-resistance to aryloxyphenoxypropionates (APPs) herbicides metamifop (2.9-fold) and fenoxapro-p-ethyl (4.1-fold), cyclohexanediones (CHDs) herbicide clethodim (4.7-fold), phenyl pyrazoline (DEN) herbicide pinoxaden (6.4-fold), and evolved multiple-resistance to acetolactate synthase (ALS)-inhibiting herbicide penoxsulam (3.6-fold), and auxin mimic herbicides quinclorac (>34.7-fold) and florpyrauxifen-benzyl (2.4-fold). ACCase gene sequencing did not reveal the existence of any known mutation point conferring with herbicide resistance. In addition, three metabolic inhibitors—one glutathione—S-transferase (GST) inhibitor (NBD-Cl), and two cytochrome P450 inhibitors (malathion and PBO)—did not reverse the cyhalofop-butyl resistance. Furthermore, enhanced metabolic rates of more than 60% 24 h after treatment with the active compound cyhalofop acid was observed in R plants compared to S plants. Hence, enhanced metabolism activity endows a non-target-site resistance to cyhalofop-butyl in the R population of E. crus-galli. Future research will be required to determine what metabolizing enzyme genes are responsible for cyhalofop-butyl resistance in E. crus-galli.

Enhanced Herbicide Metabolism and Target Site Mutation Enabled the Multiple Resistance to Cyhalofop-butyl, Florpyrauxifen-benzyl, and Penoxsulam in Echinochloa crus-galli

“…With the extensive application of herbicides, multiple herbicide-resistant weed populations have been increasing rapidly in the past decade, which has been reported in E. phyllopogon, 24 E. crus-galli, 25,26 Eleusine indica, 27 L. rigidum, 28 and so on. The fast increase of MHR weeds would seriously S7.…”

Ile-1781-Leu Target Mutation and Non-Target-Site Mechanism Confer Resistance to Acetyl-CoA Carboxylase-Inhibiting Herbicides in Digitaria ciliaris var. chrysoblephara

“…In the past decade, ACCase inhibitors, cyhalofop-butyl and metamifop, were the common herbicides to control this noxious weed in rice fields. It is no surprise that ACCase-inhibitor-resistant grass weeds, including L. chinensis, 6,22−24 E. crus-galli, 26,27 D. fusca, 25 and E. indica, 30 have frequently occurred in rice fields as a result of persistent herbicide use. In this study, we identified that one D. ciliaris var.…”

“…For instance, the cyhalofop-butyl- 25 In our previous study, E. crus-galli populations collected from Ningxia and Jiangxi provinces were found to evolve resistance to cyhalofop-butyl and metamifop. 26,27 In recent years, the farmers generally report that metamifop and cyhalofop-butyl have poor control effect on D. ciliaris var. chrysoblephara in seed-directing rice fields in Jiangsu and Anhui provinces of China.…”

Identification, mapping, and chemical control of fleabane resistant to glyphosate, chlorimuron, paraquat, and 2,4-D

“…For glyphosate, it was not possible to adjust to the model proposed by Streibig (1988). Thus, data were submitted to regression analysis (P < 0.05) using a four-parameter nonlinear logistic model (Seefeldt et al 1995), as used in other studies (Wu et al 2022; Yang et al 2022): …”