Detection of resistance to acetolactate synthase inhibitors in weeds with emphasis on DNA‐based techniques: a review

Abstract

Resistance to herbicides inhibiting acetolactate synthase (ALS) has been increasing at a faster rate than in any other herbicide group. The great majority of these cases are due to various single-nucleotide polymorphisms in the ALS gene endowing target site resistance. Many diagnostic techniques have been devised in order to confirm resistance and help producers to adopt the best management strategies. Recent advances in DNA technologies coupled with the knowledge of sequence information have allowed the development of accurate and rapid diagnostic tests. While whole plant-based diagnostic techniques such as seedling bioassays or enzyme-based in vitro bioassays provide accurate results, they tend to be labour- and/or space-intensive and will only respond to the particular herbicides tested, making resolution of cross-resistance patterns more difficult. Successful DNA-based diagnosis of ALS inhibitor resistance has been achieved with three main techniques, (1) restriction fragment length polymorphism, (2) polymerase chain reaction amplification of specific alleles and (3) denaturing high-performance liquid chromatography. All DNA-based techniques are relatively rapid and provide clear identification of the mutations causing resistance. Resistance based on non-target mechanisms is not identified by these DNA-based methods; however, given the prevalence of target site-based ALS inhibitor resistance, this is a minor inconvenience.

Activity of acetolactate synthase (ALS) of redroot pigweed in relation to imazethapyr application

“…Morphometric parameters were analyzed in many methods that are applied for weed resistance to herbicides from different chemical groups (Beckie et al, 2000;Hanson et al, 2004;Corbett and Tardif, 2006).…”

Properties of controlled-release formulation of pyrimisulfan as a one-shot herbicide in a paddy field

“…e mutation sites of acetolactate synthase (ALS) genes of these SU-resistant weeds have been determined by PCR-RFLP. [10][11][12] Plants of SU-resistant weeds were initially screened by applying bensulfuron-methyl (75 g (121°C, 20 min), was added to a 450 mL plastic cup, followed by the addition of 200 mL water. Pre-diluted 10% WP pyrimisulfan was then added to the cup at 0, 0.2, 1.0, 2.0, 4.0, 8.0, 12, 16, 20, 40, 80, and 120 ppb.…”

Diagnóstico da resistência aos herbicidas em plantas daninhas

“…Com o advento da biologia molecular, trabalhos têm sido realizados utilizando técnicas moleculares a partir do DNA, que também per mitem otimizar o tempo na confirmação da resistência quando esta ocorre por mecanismo de ação alterado, ou seja, mutação no sítio de ação (Délye et al, 2002;Corbett & Tardif, 2006). No entanto, há necessidade de conhecimento prévio da mutação ocorrida no gene responsável pelo local de ação herbicida e, a partir de reação de PCR (reação em cadeia de polimerase), é possível obter a confirmação da resistência ou não ao herbicida, trabalho que, em média, deve fornecer resultados muito mais rápidos que métodos clássicos de diagnóstico.…”