Skip to main content
    • Aa
    • Aa

ALS gene proline (197) mutations confer ALS herbicide resistance in eight separated wild radish (Raphanus raphanistrum) populations

  • Qin Yu (a1), Xiao Qi Zhang (a1), Abul Hashem (a2), Michael J. Walsh (a1) and Stephen B. Powles...

The biochemical and molecular basis of resistance to acetolactate synthase (ALS)–inhibiting herbicides was investigated in eight resistant (R) and three susceptible (S) wild radish populations. In vitro enzyme assays revealed an ALS herbicide–resistant ALS enzyme in all R populations. ALS enzyme extracted from the shoots of all eight R populations was highly resistant to the ALS-inhibiting sulfonylurea herbicide chlorsulfuron (20- to 160-fold) and the triazolopyrimidine herbicide metosulam (10- to 46-fold) and moderately resistant to metsulfuron (three to eightfold). There was little or no cross-resistance to the imidazolinone herbicides imazapyr and imazethapyr. The ALS gene fragment covering potential mutation sites in these populations was amplified, sequenced, and compared. All eight R populations had point mutations in the codon for the proline residue in Domain A. However, the point mutations varied and encoded four different amino acid substitutions: histidine, threonine, alanine, and serine. No nucleotide difference in the DNA sequence of Domains C and D resulting in amino acid substitutions was observed between the R and S populations examined. In addition, a three- to fivefold higher ALS-specific activity was consistently observed in all R populations compared with S populations, whereas Northern blot analysis detected a similar level of ALS mRNA, suggesting a possible translational–posttranslational regulation of the enzyme. It is concluded that selection pressure from chlorsulfuron on eight separate wild radish populations has resulted in target site mutation at the same proline residue in the ALS gene. Higher ALS activity also may play a role in the resistance level.

Corresponding author
Corresponding author. Western Australian Herbicide Resistance Initiative, School of Plant Biology, University of Western Australia, Crawley, WA 6009, Australia
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

S. W. Adkins , D. Wills , M. Boersma , S. R. Walker , G. Robinson , R. J. McLeod , and J. P. Einam 1997. Weed resistance to chlorsulfuron and atrazine from the north-east grain region of Australia. Weed Res 37:343349.

P. Bernasconi , A. R. Woodworth , B. A. Rosin , M. V. Subramanian , and D. L. Siehl 1995. A naturally occurring point mutation confers broad range tolerance to herbicides that target acetolactate synthase. J. Biol. Chem 270:1738117385.

P. Boutsalis , J. Karotam , and S. B. Powles 1999. Molecular basis of resistance to acetolactate synthase-inhibiting herbicides in Sisymbrium orientale and Brassica tournefortii . Pestic. Sci 55:507516.

P. Boutsalis and S. B. Powles 1995a. Resistance of dicot weeds to acetolactate synthase (ALS)-inhibiting herbicides in Australia. Weed Res 35:149155.

P. Boutsalis and S. B. Powles 1995b. Inheritance and mechanism of resistance to herbicides inhibiting acetolactate systhase in Sonchus oleraceus L. Theor. Appl. Genet 91:242247.

M. M. Bradford 1976. A rapid and sensitive method for quantitation of microgram quantities of protein utilising the principle of protein binding. Anal. Biochem 72:248254.

J. T. Christopher , S. B. Powles , and J. A. M. Holtum 1992. Resistance to acetolactate synthase–inhibiting herbicides in annual ryegrass (Lolium rigidum) involves at least two mechanisms. Plant Physiol 100:19091913.

J. C. Cotterman and L. L. Saari 1992. Rapid metabolic inactivation is the basis for cross-resistance to chlorsulfuron in diclofop-methyl-resistant rigid ryegrass (Lolium rigidum) biotype SR4/84. Pestic. Biochem. Physiol 43:182192.

E. Dewaele , G. Forlani , D. Degrande , E. Nielsen , and S. Rambour 1996. Biochemical characterization of chlorsulfuron resistance in Cichorium intybus L. var. Witloof. J. Plant Physiol 151:109114.

A. J. Fisher , D. E. Bayer , M. D. Carriere , C. M. Ateh , and K. O. Yim 2000. Mechanisms of resistance to bispyribac-sodium in an Echnochloa phyllopogon accession. Pestic. Biochem. Physiol 68:156165.

A. Hashem , D. Bowran , T. Piper , and H. Dhammu 2001. Resistance of wild radish (Raphanus raphanistrum) to acetolactate synthase-inhibiting herbicides in the Western Australian wheat belt. Weed Technol 15:6874.

J. Hattori , D. Brown , G. Mourad , H. Labbé , T. Ouellet , G. Sunohara , R. Rutledge , J. King , and B. Miki 1995. An acetohydroxyacid synthase mutant reveals a single site involved in multiple herbicide resistance. Mol. Gen. Genet 246:419425.

G. W. Haughn and C. Somerville 1986. Sulfonylurea-resistant mutants of Arabidopsis thaliana . Mol. Gen. Genet 204:430434.

R. S. Llewellyn and S. B. Powles 2001. High levels of herbicide resistance in rigid ryegrass (Lolium rigidum) in the wheat belt of Western Australia. Weed Technol 15:242248.

G. Mourad and J. King 1992. Effect of four classes of herbicides on growth and acetolactase-synthase activity in several variants of Arabidopsis thaliana . Planta 188:491497.

J. T. Odell , P. G. Caimi , N. S. Yadav , and C. J. Mauvais 1990. Comparison of increased expression of wild-type and herbicide-resistant acetolactate synthase genes in transgenic plants, and indication of posttranscriptional limitation on enzyme activity. Plant Physiol 94:16471654.

W. L. Patzoldt and P. L. Tranel 2002. Molecular analysis of cloransulam resistance in a population of giant ragweed. Weed Sci 50:299305.

B. Rathinasabapathi , D. Williams , and J. King 1990. Altered feedback sensitivity to valine, leucine and isoleucine of acetolactate synthase from herbicide-resistant variants of Datura innoxia . Plant Sci 67:16.

T. B. Ray 1984. Site of action of chlorsulfuron—inhibition of valine and isoleucine biosynthesis in plants. Plant Physiol 75:827831.

M. V. Subramanian , V. Lonvy-Gallant , J. M. Dias , and L. C. Mireles 1991. Acetolactate synthase inhibiting herbicides bind to the regulatory site. Plant Physiol 96:310313.

M. K. Tan and R. W. Medd 2002. Characterisation of the acetolactate synthase (ALS) gene of Raphanus raphanistrum L. and the molecular assay of mutations associated with herbicide resistance. Plant Sci 163:195205.

P. J. Tranel and T. R. Wright 2003. Resistance of weeds to ALS inhibiting herbicides: what have we learned. Weed Sci 50:700712.

A. Uchino and H. Watanabe 2002. Mutations in the acetolactate synthase genes of sulfonylurea-resistant biotypes of Lindernia spp. Weed Biol. Manag 2:104109.

L. J. Veldhuis , L. M. Hall , J. T. O'Donovan , W. Dyer , and J. C. Hall 2000. Metabolism-based resistance of a wild mustard (Sinapis arvensis L.) biotype to ethametsulfuron-methyl. J. Agric. Food Chem 48:29862990.

C. Venugopalan and H. C. Kapoor 1997. Single step isolation of plant RNA. Phytochemistry 46:13031305.

M. J. Walsh , R. D. Duane , and S. B. Powles 2001. High frequency of chlorsulfuron-resistant wild radish (Raphanus raphanistrum) populations across the Western Australian wheat belt. Weed Technol 15:199203.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Weed Science
  • ISSN: 0043-1745
  • EISSN: 1550-2759
  • URL: /core/journals/weed-science
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Abstract views

Total abstract views: 37 *
Loading metrics...

* Views captured on Cambridge Core between 20th January 2017 - 24th June 2017. This data will be updated every 24 hours.