Affiliation:
1. State Key Laboratory for Biology of Plant Diseases and Insert Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
2. Institute of Plant Protection, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China
Abstract
Bromus japonicus is a common monocot weed that occurs in major winter wheat fields in the Huang–Huai–Hai region of China. Pyroxsulam is a highly efficient and safe acetolactate synthase (ALS)-inhibiting herbicide that is widely used to control common weeds in wheat fields. However, B. japonicus populations in China have evolved resistance to pyroxsulam by different mutations in the ALS gene. To understand the resistance distribution, target-site resistance mechanisms, and cross-resistance patterns, 208 B. japonicus populations were collected from eight provinces. In the resistant population screening experiment, 59 populations from six provinces showed different resistance levels to pyroxsulam compared with the susceptible population, of which 17 B. japonicus populations with moderate or high levels of resistance to pyroxsulam were mainly from the Hebei (4), Shandong (4) and Shanxi (9) Provinces. Some resistant populations were selected to investigate the target site-resistance mechanism to the ALS-inhibiting herbicide pyroxsulam. Three pairs of primers were designed to amplify the ALS sequence, which was assembled into the complete ALS sequence with a length of 1932 bp. DNA sequencing of ALS revealed that four different ALS mutations (Pro-197-Ser, Pro-197-Thr, Pro-197-Phe and Asp-376-Glu) were found in 17 moderately or highly resistant populations. Subsequently, five resistant populations, QM21-41 with Pro-197-Ser, QM20-8 with Pro-197-Thr and Pro-197-Phe, and QM21-72, QM21-76 and QM21-79 with Asp-376-Glu mutations in ALS genes, were selected to characterize their cross-resistance patterns to ALS inhibitors. The QM21-41, QM20-8, QM21-72, QM21-76 and QM21-79 populations showed broad-spectrum cross-resistance to pyroxsulam, mesosulfuron–methyl and flucarbazone–sodium. This study is the first to report evolving cross-resistance to ALS-inhibiting herbicides due to Pro-197-Phe mutations in B. japonicus.
Funder
National Key Research and Development Program of China
Technology Innovation Project, Chinese Academy of Agricultural Sciences
Reference44 articles.
1. Biological characteristics of Japanese brome observed in the wheat of Zhuanglang country;Wei;Gansu Agric. Sci. Technol,2010
2. (2023, April 01). Flora of China. Available online: www.iplant.cn/foc.
3. Lan, Y., Zhou, X., Lin, S., Cao, Y., Wei, S., Huang, H., Li, W., and Huang, Z. (2022). Pro-197-Ser Mutation and Cytochrome P450-Mediated Metabolism Conferring Resistance to Flucarbazone-Sodium in Bromus japonicus. Plants, 11.
4. Target-site basis for resistance to flucarbazone-sodium in Japanese brome (Bromus japonicus Houtt.) in China;Li;Chil. J. Agric. Res.,2022
5. The Pro-197-Thr mutation in the ALS gene confers novel resistance patterns to ALS-inhibiting herbicides in Bromus japonicus in China;Liu;Front. Plant Sci.,2024