ALS Gene Mutations in Apera Spica-Venti Confer Broad-Range Resistance to Herbicides

Abstract

ALS Gene Mutations in Apera Spica-Venti Confer Broad-Range Resistance to Herbicides Several biotypes of wind bentgrass in Poland have been identified as being resistant to acetolactate synthase (ALS) inhibitors. We screened these weeds with chlorsulfuron and performed a whole-plant bioassay with a range of doses based on these four herbicides: chlorsulfuron, sulfosulfuron, propoxycarbazone-sodium and mesosulfuron-methyl + iodosulfuron-methyl-sodium mixture. Ten biotypes, diverse in their levels of resistance, were submitted for molecular tests. PCR amplification and sequencing of als domains demonstrated numerous single nucleotide polymorphisms. Nine biotypes showed non-synonymous substitutions in codon Pro197, changing it to Ser or Thr. Mutation in Pro197 conferred a high level of resistance to the tested herbicides. Analysis of four biotypes also revealed a substitution in the Ala122 codon, changing it to Val. In one biotype this substitution was not accompanied by Pro197 mutation and this biotype was resistant to chlorsulfuron and mesosulfuron + iodosulfuron, but not to sulfosulfuron or propoxycarbazone-sodium. Correspondence between mutations and levels of resistan ce to ALS inhibitors may support management of resistant weeds with the existing palette of herbicides.

A strategy of chemical control of Apera spica-venti L. resistant to sulfonylureas traced on the molecular level

“…Similar results were obtained by Krysiak et al (2011) and Hamouzova et al (2014). Th e probable cause of this might be the existence of another mechanism of resistance, for example enhanced metabolism.…”

“…Th is mutation, which occurs the most frequently, is known to confer resistance to sulfonylureas, with 11 documented amino acid substitutions endowing resistance to ALS-inhibiting herbicides (Powles and Yu 2010;Krysiak et al 2011;Massa et al 2011).…”

“…Primer sequences for amplifi cation of domains A and B and the area between these domains of the als gene were as described by Krysiak et al (2011). Genomed S.A. (Warsaw, Poland) was commissioned to undertake purifi cation of the PCR product and sequencing.…”

Tribenuron-methyl resistance and mutation diversity of Pro197 in flixweed (Descurainia Sophia L.) accessions from China

“…Among these substitutions, the Pro197-Tyr/Pro mutation caused by two successive nucleotide changes (CCT to TAT) has never been reported previously in AHAS herbicide resistant weeds [1]. A mutation of Ala-122-Tyr was firstly identified in wild radish (Raphanus raphanistrum L.), which conferred remarkable different AHAS herbicide resistance comparing with the Ala-122-Thr and Ala-122-Val mutations [7,[25][26][27]. In addition, Pro197-His and Pro197-His/Pro mutations were identified for the first time in flixweed.…”

Mechanisms of resistance to acetolactate synthase‐inhibiting herbicides in populations of Apera spica‐venti from the Czech Republic

“…Some populations of A. spica‐venti have an insensitive target enzyme. So far, three mutations (Thr, Ala and Ser) at Pro‐197 and one mutation (Leu) at Thr‐574 have been described in A. spica‐venti . In addition, one novel mutation was found within a population that coded for an His substitution at Arg‐377 .…”