Skip to main content Accessibility help

Target site–based resistance to penoxsulam in late watergrass (Echinochloa phyllopogon) from China

  • Jian Liu (a1), Jiapeng Fang (a2), Zongzhe He (a2), Jun Li (a3) and Liyao Dong (a4)...


Late watergrass [Echinochloa phyllopogon (Stapf) Koso-Pol.] is one of the most persistent weeds in rice fields and shows resistance to some acetolactate synthase (ALS)-inhibiting herbicides, such as penoxsulam. Previous studies of E. phyllopogon’s herbicide resistance have focused on non–target site resistance mechanisms. In this study, E. phyllopogon populations from Heilong Jiang Province, China, that were possibly resistant to penoxsulam were used to identify the target site–based mechanisms of resistance. Population HSRH-520 showed a 25.4-fold higher resistance to penoxsulam than the sensitive population, HSRH-538. HSRH-520 was resistant to other ALS inhibitors, with resistance indexes ranging from 17.1 to 166. Target-gene sequence analysis revealed two different ALS genes in E. phyllopogon; a Pro-197-Ser substitution occurred in the ALS-2 gene of HSRH-520. In vitro activity assays revealed that the penoxsulam concentrations required to inhibit 50% of the ALS activity were 13.7 times higher in HSRH-520 than in HSRH-538. Molecular-docking tests showed that the Pro-197-Ser mutation reduced the binding affinity between ALS and ALS inhibitors belonging to the triazolopyrimidine, sulfonylaminocarbonyltriazolinone, and sulfonylurea families, and there were almost no effects on binding affinity when the ALS inhibitors were of the pyrimidinylthiobenzoate and imidazolinone families. Overall, the results indicated and verified that the Pro-197-Ser mutation leads to increased ALS activity by reducing the binding affinity of the inhibitor and ALS. This is the first report on the Pro-197-Ser mutation in the complete ALS gene of E. phyllopogon and will aid future research of target site–based resistance mechanisms of E. phyllopogon to ALS inhibitors.


Corresponding author

Author for correspondence: Liyao Dong; Email:


Hide All
Ashigh, J, Tardif, FJ (2007) An Ala(205)Val substitution in acetohydroxyacid synthase of eastern black nightshade (Solanum ptychanthum) reduces sensitivity to herbicides and feedback inhibition. Weed Sci 55:558565
Beckie, HJ, Tardif, FJ (2012) Herbicide cross resistance in weeds. Crop Prot 35:1528
Bi, YL, Liu, WT, Li, LX, Yuan, GH, Jin, T, Wang, JX (2013) Molecular basis of resistance to mesosulfuron-methyl in Japanese foxtail, Alopecurus japonicus. J Pestic Sci 38:7477
Cui, HL, Li, XJ, Wang, GQ, Wang, JP, Wei, SH, Cao, HY (2012) Acetolactate synthase proline (197) mutations confer tribenuron-methyl resistance in Capsella bursa-pastoris populations from China. Pestic Biochem Physiol 102:229232
Devine, MD, Eberlein, CV (1997) Physiological, biochemical and molecular aspects of herbicide resistance based on altered target sites. Pages 159185 in Roe, RM, Burton, JD, Kuhr, RJ, eds. Herbicide Activity: Toxicology, Biochemistry and Molecular Biology. Amsterdam: IOS Press
Duggleby, RG, McCourt, JA, Guddat, LW (2008) Structure and mechanism of inhibition of plant acetohydroxyacid synthase. Plant Physiol Biochem 46:309324
Feng, YJ, Gao, Y, Zhang, Y, Dong, LY, Li, J (2016) Mechanisms of resistance to pyroxsulam and ACCase inhibitors in Japanese foxtail (Alopecurus japonicus). Weed Sci 64:695704
Fischer, AJ, Ateh, CM, Bayer, DE, Hill, JE (2000) Herbicide-resistant Echinochloa oryzoides and E-phyllopogon in California Oryza sativa fields. Weed Sci 48:225230
Guttieri, MJ, Eberlein, CV, Malllory-Smith, CA, Thill, DC (1992) DNA-sequence variation in Domain A of the acetolactate synthase genes of herbicide-resistant and herbicide-susceptible weed biotypes. Weed Sci 40:670677
Han, HP, Yu, Q, Purba, E, Li, M, Walsh, M, Friesen, S, Powles, SB (2012) A novel amino acid substitution Ala-122-Tyr in ALS confers high-level and broad resistance across ALS-inhibiting herbicides. Pest Manag Sci 68:11641170
Haughn, GW, Smith, J, Mazur, B, Somerville, C (1988) Transformation with a mutant Arabidopsis acetolactate synthase gene renders tobacco resistant to sulfonylurea herbicides. Mol Gen Genet 211:266271
Haughn, GW, Somerville, C (1986) Sulfonylurea-resistant mutants of Arabidopsis thaliana. Mol Gen Genet 204:430434
Huang, ZF, Chen, JY, Zhang, CX, Huang, HJ, Wei, SH, Zhou, XX, Chen, JC, Wang, X (2016) Target-site basis for resistance to imazethapyr in redroot amaranth (Amaranthus retroflexus L.). Pestic Biochem Physiol 128:1015
Iwakami, S, Endo, M, Saika, H, Okuno, J, Nakamura, N, Yokoyama, M, Watanabe, H, Toki, S, Uchino, A, Inamura, T (2014a) Cytochrome P450 CYP81A12 and CYP81A21 are associated with resistance to two acetolactate synthase inhibitors in Echinochloa phyllopogon. Plant Physiol 165:618629
Iwakami, S, Uchino, A, Kataoka, Y, Shibaike, H, Watanabe, H, Inamura, T (2014b) Cytochrome P450 genes induced by bispyribac-sodium treatment in a multiple-herbicide-resistant biotype of Echinochloa phyllopogon. Pest Manag Sci 70:549558
Iwakami, S, Uchino, A, Watanabe, H, Yamasue, Y, Inamura, T (2012) Isolation and expression of genes for acetolactate synthase and acetyl-CoA carboxylase in Echinochloa phyllopogon, a polyploid weed species. Pest Manag Sci 68:10981106
Kaloumenos, NS, Chatzilazaridou, SL, Mylona, PV, Polidoros, AN, Eleftherohorinos, IG (2013) Target-site mutation associated with cross-resistance to ALS-inhibiting herbicides in late watergrass (Echinochloa oryzicola Vasing.). Pest Manag Sci 69:865873
Krysiak, M, Gawronski, SW, Adamczewski, K, Kierzek, R (2011) ALS gene mutations in Apera spicaventi confer broad-range resistance to herbicides. J Plant Prot Res 51:261267
Laplante, J, Rajcan, I, Tardif, FJ (2009) Multiple allelic forms of acetohydroxyacid synthase are responsible for herbicide resistance in Setaria viridis. Theor Appl Genet 119:577585
Lee, J, Kim, J-W, Lee, I-Y (2017) Distribution of cyhalofop-butyl and penoxsulam resistant Echinochloa spp. in Korean paddy fields. Weed & Turfgrass Science 6:345349
Massa, D, Krenz, B, Gerhards, R (2011) Target-site resistance to ALS-inhibiting herbicides in Apera spicaventi populations is conferred by documented and previously unknown mutations. Weed Res 51:294303
Matzenbacher, FO, Bortoly, ED, Kalsing, A, Merotto, A (2015) Distribution and analysis of the mechanisms of resistance of barnyardgrass (Echinochloa crus-galli) to imidazolinone and quinclorac herbicides. J Agric Sci 153:10441058
McCourt, JA, Pang, SS, King-Scott, J, Guddat, LW, Duggleby, RG (2006) Herbicide-binding sites revealed in the structure of plant acetohydroxyacid synthase. Proc Natl Acad Sci USA 103:569573
McCullough, PE, Yu, JL, McElroy, JS, Chen, S, Zhang, H, Grey, TL, Czarnota, MA (2016) ALS-resistant annual sedge (Cyperus compressus) confirmed in turfgrass. Weed Sci 64:3341
Mourad, G, King, J (1992) Effect of 4 classes herbicides on growth and acetolactate-synthase activity in several variants of Arabidopsis thaliana. Planta 188:491497
Panozzo, S, Scarabel, L, Tranel, PJ, Sattin, M (2013) Target-site resistance to ALS inhibitors in the polyploid species Echinochloa crus-galli. Pestic Biochem Physiol 105:93101
Powles, SB, Yu, Q (2010) Evolution in action: plants resistant to herbicides. Annu Rev Plant Biol 61:317347
Ray, TB (1984) Site of action of chlorsulfuron: inhibition of valine and isoleucine biosynthesis in plants. Plant Physiol 75:827–31
Riar, DS, Tehranchian, P, Norsworthy, JK, Nandula, V, McElroy, S, Srivastava, V, Chen, S, Bond, JA, Scott, RC (2015) Acetolactate synthase-inhibiting, herbicide-resistant rice flatsedge (Cyperus iria): cross-resistance and molecular mechanism of resistance. Weed Sci 63:748757
Shivrain, VK, Burgos, NR, Sales, MA, Kuk, YI (2010) Polymorphisms in the ALS gene of weedy rice (Oryza sativa L.) accessions with differential tolerance to imazethapyr. Crop Prot 29:336341
Sibony, M, Michel, A, Haas, HU, Rubin, B, Hurle, K (2001) Sulfometuron-resistant Amaranthus retroflexus: cross-resistance and molecular basis for resistance to acetolactate synthase-inhibiting herbicides. Weed Res 41:509522
Tatarinova, TV, Alexandrov, NN, Bouck, JB, Feldmann, KA (2010) GC(3) biology in corn, rice, sorghum and other grasses. BMC Genomics 11:18
Tranel, PJ, Wright, TR, Heap, IM (2019) The International Survey of Herbicide Resistant Weeds. Accessed: March 12, 2019
Trucco, F, Hager, AG, Tranel, PJ (2006) Acetolactate synthase mutation conferring imidazolinone-specific herbicide resistance in Amaranthus hybridus. J Plant Physiol 163:475479
Uchino, A, Ogata, S, Kohara, H, Yoshida, S, Yoshioka, T, Watanabe, H (2010) Molecular basis of diverse responses to acetolactate synthase-inhibiting herbicides in sulfonylurea-resistant biotypes of Schoenoplectus juncoides. Weed Biol Manag 7:8996
Whaley, CA, Wilson, HP, Westwood, JH (2006) ALS resistance in several smooth pigweed (Amaranthus hybridus) biotypes. Weed Sci 54:828832
Wong, GKS, Wang, J, Tao, L, Tan, J, Zhang, JG, Passey, DA, Yu, J (2002) Compositional gradients in Gramineae genes. Genome Res 12:851856
Wright, TR, Penner, D (1998) In vitro and whole-plant magnitude and cross-resistance characterization of two imidazolinone-resistant sugarbeet (Beta vulgaris) somatic cell selections. Weed Sci 46:2429
Yang, Q, Deng, W, Wang, SP, Liu, HJ, Li, XF, Zheng, MQ (2018) Effects of resistance mutations of Pro197, Asp376 and Trp574 on the characteristics of acetohydroxyacid synthase (AHAS) isozymes. Pest Manag Sci 74:18701879
Yasuor, H, Osuna, MD, Ortiz, A, Saldain, NE, Eckert, JW, Fischer, AJ (2009) Mechanism of resistance to penoxsulam in late watergrass Echinochloa phyllopogon (Stapf) Koss. J. Agric Food Chem 57:36533660
Yu, Q, Friesen, LJS, Zhang, XQ, Powles, SB (2004) Tolerance to acetolactate synthase and acetyl-coenzyme A carboxylase inhibiting herbicides in Vulpia bromoides is conferred by two co-existing resistance mechanisms. Pestic Biochem Physiol 78:2130
Yu, Q, Han, HP, Vila-Aiub, MM, Powles, SB (2010) AHAS herbicide resistance endowing mutations: effect on AHAS functionality and plant growth. J Exp Bot 61:39253934
Yu, Q, Nelson, JK, Zheng, MQ, Jackson, M, Powles, SB (2007) Molecular characterisation of resistance to ALS-inhibiting herbicides in Hordeum leporinum biotypes. Pest Manag Sci 63:918927
Yu, Q, Powles, SB (2014) Resistance to AHAS inhibitor herbicides: current understanding. Pest Manag Sci 70:13401350
Yu, Q, Zhang, XQ, Hashem, A, Walsh, MJ, Powles, SB (2003) ALS gene proline (197) mutations confer ALS herbicide resistance in eight separated wild radish (Raphanus raphanistrum) populations. Weed Sci 51:831838
Yun, MS, Yogo, Y, Miura, R, Yamasue, Y, Fischer, AJ (2005) Cytochrome P-450 monooxygenase activity in herbicide-resistant and -susceptible late watergrass (Echinochloa phyllopogon). Pestic Biochem Physiol 83:107114



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed