Mechanism of Resistance to ALS Inhibiting Herbicides in Scirpus juncoides Collected in Gyeongnam Province, Korea

Soo Yong Shim1   Sung Hwan Choi2   Jae Ho Kim3   Jung-Sung Chung4,5   WeiQiang Jia6   Kee Woong Park6   Jeung Joo  Lee5,7,*   

1Division of Applied Life Science (BK21 Plus), Gyeongsang National University, Jinju 52828, Korea
2Department of Horticulture, Gyeongnam National University of Science and Technology, Jinju 52725, Korea
3Department of Plant Medicine, College of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, Korea
4Department of Agricultural Plant Science, College of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, Korea
5Institute of Agriculture and Life Science (IALS), Gyeongsang National University, Jinju 52828, Korea
6Department of Crop Science, Chungnam National University, Daejeon 34134, Korea
7Department of Plant Medicine, College of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, Korea

Abstract

This study was conducted to determine the degree of resistance and resistance mechanism to acetolactate synthase (ALS) inhibiting herbicides in Scirpus juncoides biotypes collected in eight cities and counties in Gyeongsangnam-do. Among the S. juncoides biotypes, Goseong28 biotype was highly resistant to penoxsulam and flucetosulfuron. Based on the als gene sequencing, no mutation was found in the Goseong28 biotype. When the ALS activity of Goseong28 biotype was compared with Tongyeong238 biotype which was susceptible to penoxsulam, no significant difference was found. On the other hand, the sensitivity to penoxsulam and flucetosulfuron in the Goseong28 biotype was significantly increased in pretreatment of fenitrothion, a P450 inhibitor. It was considered that the resistance to the ALS-inhibiting herbicide in the Goseong28 biotype was not due to the mutation of als or an increase in enzymatic activity, but due to the non-target site resistance (NTSR) of P450. The low resistance to flucetosulfuron in Haman135 and Tongyeong238 was considered to be due to mutations of Pro197 of the als gene to Ser and Ala. This is the first report related to the NTSR in the S. juncoides to ALS-inhibiting herbicides, and may be used as an important reference material for studies related to the herbicide resistance in S. juncoides.

Figures & Tables

Fig. 1.Growth response of biotypes 14 days after penoxsulam (A) and flucetosulfuron (B) treatment. C: Control; 1/48: 0.625 g; 1/32: 0.9375 g; 1/16: 1.875 g; 1/8: 3.75 g; 1/4: 7.5 g; 1: 30 g; 8: 240 g; 16: 480 g; 32: 960 g; 64: 1920 g a.i. ha.