DNA Sequence Variation in Domain a of the Acetolactate Synthase Genes of Herbicide-Resistant and -Susceptible Weed Biotypes

Weed Science ◽  
1992 ◽  
Vol 40 (4) ◽  
pp. 670-677 ◽  
Author(s):  
Mary J. Guttieri ◽  
Charlotte V. Eberlein ◽  
Carol A. Mallory-Smith ◽  
Donald C. Thill ◽  
David L. Hoffman
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Dna Sequence ◽  
Sequence Variation ◽  
Polymerase Chain Reaction Amplification ◽  
Single Point ◽  
Acetolactate Synthase ◽  
Single Point Mutation ◽  
Dna Sequence Variation ◽  
Prickly Lettuce

The DNA sequence of a 196 base pair (bp) region of the acetolactate synthase (ALS) genes of three weed species, kochia, prickly lettuce, and Russian thistle, was determined. This region encompasses the coding sequence for Domain A, a region of the amino acid sequence previously demonstrated to play a pivotal role in conferring resistance to herbicides that inhibit ALS. The Domain A DNA sequence from a chlorsulfuron-resistant (R) prickly lettuce biotype from Idaho differed from that of a chlorsulfuron-susceptible (S) biotype by a single point mutation, which substituted a histidine for a proline. The Domain A DNA sequence from an R kochia biotype from Kansas also differed from that of an S biotype by a single point mutation in the same proline codon. This point mutation, however, conferred substitution of threonine for proline. Two different ALS-homologous sequences were isolated from an R biotype of Russian thistle. Neither sequence encoded amino acid substitutions in Domain A that differed from the consensus S sequence. The DNA sequence variation among the R and S kochia biotypes was used to characterize six Ada County, Idaho, kochia collections for correlation between phenotypic chlorsulfuron susceptibility and restriction digest patterns (RFLPs) of polymerase chain reaction amplification products. Most collections showed excellent correspondence between the RFLP patterns and the phenotypic response to chlorsulfuron application. However, one entirely R collection had the RFLP pattern of the S biotype, suggesting that resistance was not due to mutation in the proline codon.

Point mutation in acetolactate synthase confers sulfonylurea and imidazolinone herbicide resistance in spiny annual sow-thistle [Sonchus asper (L.) Hill]

2012 ◽  
Vol 92 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Kee Woong Park ◽  
Judith M. Kolkman ◽  
Carol A. Mallory-Smith
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Herbicide Resistance ◽  
Single Point ◽  
Acetolactate Synthase ◽  
Amino Acid Sequences ◽  
Cross Resistance ◽  
Single Point Mutation ◽  
Sonchus Asper

Park, K. W., Kolkman, J. M. and Mallory-Smith, C. A. 2012. Point mutation in acetolactate synthase confers sulfonylurea and imidazolinone herbicide resistance in spiny annual sow-thistle [Sonchus asper (L.) Hill]. Can. J. Plant Sci. 92: 303–309. Suspected thifensulfuron resistant spiny annual sow-thistle was identified near Colfax, Washington, in two fields with a winter wheat and lentil rotation. Therefore, studies were conducted to examine resistance of spiny annual sow-thistle to thifensulfuron and cross-resistance to other acetolactate synthase inhibitors and to determine the physiological and molecular basis for herbicide resistance. Whole-plant bioassay confirmed that the biotype was highly resistant to the sulfonylurea (SU) herbicides, thifensulfuron, metsulfuron, and prosulfuron. The resistant (R) biotype was also highly resistant to the imidazolinone (IMI) herbicides, imazamox and imazethapyr. An in vivo acetolactate synthase (ALS) assay indicated that the concentrations of SU and IMI herbicides required for 50% inhibition (I50) were more than 10 times greater for R biotype compared with susceptible (S) biotype. Analysis of the nucleotide and predicted amino acid sequences for ALS genes demonstrated a single-point mutation from C to T at the als1 gene, conferring the substitution of the amino acid leucine for proline in the R biotype at position197. The results of this research indicate that the resistance of spiny annual sow-thistle to SU and IMI herbicides is due to on altered target site and caused by a point mutation in the als1 gene.

Molecular Basis of Resistance to ALS-Inhibitor Herbicides in Greater Beggarticks

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 474-481 ◽  
Author(s):  
Fabiane P. Lamego ◽  
Dirk Charlson ◽  
Carla A. Delatorre ◽  
Nilda R. Burgos ◽  
Ribas A. Vidal
Keyword(s):  
Amino Acid ◽  
Molecular Basis ◽  
Single Point ◽  
Acetolactate Synthase ◽  
Amino Acid Sequences ◽  
Single Point Mutation ◽  
Weed Species ◽  
Herbicide Resistant ◽  
Als Inhibitors ◽  
Als Inhibitor

Soybean is a major crop cultivated in Brazil, and acetolactate synthase (ALS)-inhibiting herbicides are widely used to control weeds in this crop. The continuous use of these ALS-inhibiting herbicides has led to the evolution of herbicide-resistant weeds worldwide. Greater beggarticks is a polyploid species and one of the most troublesome weeds in soybean production since the discovery of ALS-resistant biotypes in 1996. To confirm and characterize the resistance of greater beggarticks to ALS inhibitors, whole-plant bioassays and enzyme experiments were conducted. To investigate the molecular basis of resistance in greater beggarticks theALSgene was sequenced and compared between susceptible and resistant biotypes. Our results confirmed that greater beggarticks is resistant to ALS inhibitors and also indicated it possesses at least three isoforms of theALSgene. Analysis of the nucleotide and deduced amino acid sequences among the isoforms and between the biotypes indicated that a single point mutation, G–T, in oneALSisoform from the resistant biotype resulted in an amino acid substitution, Trp574Leu. Two additional substitutions were observed, Phe116Leu and Phe149Ser, in a second isoform of the resistant biotype, which were not yet reported in any other herbicide-resistantALSgene; thus, their role in conferring herbicide resistance is not yet ascertained. This is the first report ofALSmutations in an important, herbicide-resistant weed species from Brazil.

scholarly journals A single point mutation of hamster aminoacyl‐tRNA synthetase causes apoptosis by deprivation of cognate amino acid residue

1996 ◽  
Vol 1 (12) ◽  
pp. 1087-1099 ◽  
Author(s):  
Kohtaro Fukushima ◽  
Seiichi Motomura ◽  
Akio Kuraoka ◽  
Hitoo Nakano ◽  
Takeharu Nishimoto
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Amino Acid Residue ◽  
Single Point ◽  
Trna Synthetase ◽  
Single Point Mutation ◽  
Aminoacyl Trna Synthetase

scholarly journals Site-specific single point mutation by anthranilic acid in hIAPP8–37 enhances anti-amyloidogenic activity

2021 ◽  
Vol 2 (1) ◽  
pp. 266-273
Author(s):  
Sourav Kalita ◽  
Sujan Kalita ◽  
Ashim Paul ◽  
Manisha Shah ◽  
Sachin Kumar ◽  
...  
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Anthranilic Acid ◽  
Single Point ◽  
Single Point Mutation ◽  
Amyloid Formation ◽  
Site Specific

β-Amino acid based peptidomimetics are attractive scaffolds for therapeutics design towards T2D. They prevent amyloid formation of hIAPP by forming non-fibrillar non-toxic aggregates.

scholarly journals A Single Point Mutation, Asn16→Lys, Dictates the Temperature-Sensitivity of the Reovirus tsG453 Mutant

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 289
Author(s):  
Kathleen K. M. Glover ◽  
Danica M. Sutherland ◽  
Terence S. Dermody ◽  
Kevin M. Coombs
Keyword(s):  
Amino Acid ◽  
Temperature Sensitivity ◽  
Reverse Genetics ◽  
Core Protein ◽  
Single Point ◽  
Single Amino Acid ◽  
Single Point Mutation ◽  
Temperature Sensitive ◽  
Amino Acid Substitutions ◽  
Gene Encoding

Studies of conditionally lethal mutants can help delineate the structure-function relationships of biomolecules. Temperature-sensitive (ts) mammalian reovirus (MRV) mutants were isolated and characterized many years ago. Two of the most well-defined MRV ts mutants are tsC447, which contains mutations in the S2 gene encoding viral core protein σ2, and tsG453, which contains mutations in the S4 gene encoding major outer-capsid protein σ3. Because many MRV ts mutants, including both tsC447 and tsG453, encode multiple amino acid substitutions, the specific amino acid substitutions responsible for the ts phenotype are unknown. We used reverse genetics to recover recombinant reoviruses containing the single amino acid polymorphisms present in ts mutants tsC447 and tsG453 and assessed the recombinant viruses for temperature-sensitivity by efficiency-of-plating assays. Of the three amino acid substitutions in the tsG453 S4 gene, Asn16-Lys was solely responsible for the tsG453ts phenotype. Additionally, the mutant tsC447 Ala188-Val mutation did not induce a temperature-sensitive phenotype. This study is the first to employ reverse genetics to identify the dominant amino acid substitutions responsible for the tsC447 and tsG453 mutations and relate these substitutions to respective phenotypes. Further studies of other MRV ts mutants are warranted to define the sequence polymorphisms responsible for temperature sensitivity.

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