Insights into the ALS inhibitor resistance in Amaranthus retroflexus: A matter of concern for CONVISO® SMART sugar beet cultivation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60460709%3A41210%2F25%3A102406" target="_blank" >RIV/60460709:41210/25:102406 - isvavai.cz</a>

Result on the web

<a href="https://onlinelibrary.wiley.com/doi/full/10.1111/wre.12676" target="_blank" >https://onlinelibrary.wiley.com/doi/full/10.1111/wre.12676</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/wre.12676" target="_blank" >10.1111/wre.12676</a>

Result language

angličtina

Original language name

Insights into the ALS inhibitor resistance in Amaranthus retroflexus: A matter of concern for CONVISO® SMART sugar beet cultivation

Original language description

Amaranthus retroflexus L. has recently become a problematic weed in CONVISO® SMART sugar beet fields in the Czech Republic, largely due to the rapid adoption of this system and widespread application of ALS inhibiting herbicides in almost all crops, including other systems using ALS herbicide tolerant varieties. In this study, two A. retroflexus biotypes, suspected to be resistant to ALS inhibitors, were collected from CONVISO® SMART sugar beet field. Studies were conducted to confirm their resistance status and investigate the underlying mechanisms. The findings reveal that these biotypes have developed resistance to foramsulfuron + thiencarbazone-methyl, with cross-resistance to imazamox and tribenuron-methyl. The dose–response studies revealed that the resistant (R) biotypes AMARE1 and AMARE2 are 351 and 12 times less sensitive to foramsulfuron + thiencarbazone-methyl than the susceptible (S) biotype. Upon pretreatment with malathion, the resistance index decreased 2X in AMARE1, indicating the potential involvement of cytochrome P450 in the resistance mechanism. However, no involvement of GSTs was detected following NBD-Cl pretreatment. Furthermore, a higher ALS enzyme activity was observed in both R biotypes compared to the S biotype. Finally, molecular analysis revealed that a single nucleotide substitution had occurred in the ALS gene, conferring a tryptophan (Trp) to Leucine (Leu) substitution at position 574 of the ALS enzyme involved as a probable target-site resistance mechanism in both R biotypes. In summary, our study identified point mutation and enhanced metabolism by cytochrome P450s are likely mechanisms of resistance to foramsulfuron + thiencarbazone-methyl in the AMARE1 biotype, while point mutation was found the sole responsible mechanism of resistance involved in AMARE2. The current study reports the first instance of resistance in A. retroflexus against foramsulfuron + thiencarbazone-methyl. This evolution highlights the dynamic response of weed populations to herbicide pressure and underscores the need for alternative weed control strategies in sugar beet including rotating ALS-tolerant crops with the traditional (non-tolerant) crops, to limit ALS inhibitor use and resistance evolution.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

40106 - Agronomy, plant breeding and plant protection; (Agricultural biotechnology to be 4.4)

Project

<a href="/en/project/QL24010167" target="_blank" >QL24010167: Revealing herbicide and insecticide resistance mechanisms and applications of antiresistant strategies while reducing the pesticide consumption</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Weed Research

ISSN

0043-1737

e-ISSN

1365-3180

Volume of the periodical

65

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

8

Pages from-to

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UT code for WoS article

001391165300001

EID of the result in the Scopus database

2-s2.0-85213363327