Mutations in corn (Zea mays L.) conferring resistance to imidazolinone herbicides

Newhouse, K. E.; Singh, Bijay; Shaner, Dale L.; Stidham, Mark A.

doi:10.1007/bf00229227

Cited by 115 publications

(87 citation statements)

References 24 publications

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“…The characteristics of the imidazolinone-tolerant wheat described in this study are similar in many respects to other imidazolinone-tolerant and sulfonylurea-tolerant plant selections previously reported in the literature (1,5,6,11,14,20 (6,7,11,20). The imidazolinone tolerance in wheat reported here is conferred through AHAS activity that is insensitive to inhibition by the imidazolinone herbicides ( Fig.…”

Section: Resultssupporting

confidence: 85%

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Tolerance to Imidazolinone Herbicides in Wheat

Newhouse¹,

Smith²,

Starrett³

et al. 1992

Plant Physiol.

128

122

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An imidazolinone-tolerant wheat (Triticum aestivum L. em Thell) mutant in the winter wheat cultivar Fidel has been identified and characterized. The mutant was isolated from a population derived through seed mutagenesis of the variety with an aqueous solution containing sodium azide. Imidazolinone-tolerant wheat seedlings were selected from the M2 generation of the population in the presence of imazethapyr herbicide and identified as herbicideinsensitive individuals. The trait is inherited as a single semidominant gene and confers high levels of tolerance to imazethapyr. Acetohydroxyacid synthase activity in extracts from imidazolinonetolerant plants was less inhibited by imazethapyr than the enzyme from the wild type. The herbicide-tolerant plants have a completely normal phenotype and display no negative effects on growth and yield in either the absence or presence of imazethapyr.find imidazolinone-tolerant wheat (Triticum aestivum L. em Thell) through seed mutagenesis and selection with an M2 seedling screen. MATERIALS AND METHODS Seed MutagenesisFive thousand seeds of the French winter wheat (Triticum aestivum L. em Thell cv Fidel) were mutagenized by the procedure of Kueh and Bright (9). Wheat seeds were soaked in water for 18 h at 50C. Air was then bubbled through the seeds for 6 h at 200C. Following imbibition, seeds were soaked in 1 mm sodium azide (pH 3) for 2 h. The seeds were rinsed for 30 min, dried on paper towels, and planted in the field. The plants arising from these seeds were Ml generation plants. M2 seeds were harvested from these plants at maturity.The imidazolinone class of herbicides has been demonstrated to have a broad spectrum of weed control activity, flexibility in timing of application, low usage rates, and low mammalian toxicity. These herbicides inhibit the enzymic activity of AHAS2 (EC 4.1.3.18) (15), the first enzyme in the pathway for the synthesis of the branched chain amino acids valine, leucine, and isoleucine. This same enzyme has been shown to be the site of action for the sulfonylurea and triazolopyrimidine herbicides (4,19). The basis for crop selectivity of the imidazolinones has been shown to be the result of a difference in the nature or rate of metabolism of the herbicide (2,3,16 882Screening Procedure M2 seeds were surface disinfected in 70% ethanol for 30 s. This was followed by a disinfection in a solution of 2.6% sodium hypochlorite for 30 min under vacuum with gentle agitation. Two drops of the nonionic surfactant Tween 20 were used per 100 mL of the sodium hypochlorite solution to aid the disinfestation procedure. Subsequently, seeds were rinsed three times in sterile distilled water and placed into sterile plastic 10-x 1.5-cm Petri dishes at 250 seeds/dish. Twenty-five milliliters of 1 M imazethapyr was placed in each dish. After 3 d in the imazethapyr solution, the seeds were drained and blotted dry. The seeds were planted at a 1-to 2-cm depth in 15-x 20-cm peat flats containing Metromix 350 (W.R. Grace Co.) at the rate of 1000 seeds/flat. These flats...

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Section: Resultssupporting

confidence: 85%

“…These results are consistent with the finding of unaltered feedback regulation of AHAS from imidazolinone-resistant or sulfonylurea-resistant mutant lines (ref. 11 and references cited therein). These results reiterate our earlier conclusion that the herbicide's binding sites and the feedback inhibitors' binding sites are distinct (11).…”

Section: Resultsmentioning

confidence: 99%

Tolerance to Imidazolinone Herbicides in Wheat

Newhouse¹,

Smith²,

Starrett³

et al. 1992

Plant Physiol.

128

122

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“…Plantas resistentes aos herbicidas foram regeneradas, e verificou-se que a resistência ocorreu devido a uma insensibilidade da enzima acetolactato sintase (ALS) aos herbicidas do grupo químicos das imidazolinonas (NEWHOUSE et al, 1991). Alguns casos de resistência, obtidos por essa técnica, têm sido ineficientes em condições de avaliação de campo (FALCO et al, 1989 …”

Section: Seleção De Células E Cultura De Tecidosunclassified

“…Existem exemplos de efeitos pleitrópicos devido aos novos genes, como a l t e r a ç ã o n a m o r f o l o g i a f l o r a l e m a l g o d ã o resistente ao glifosato o que resulta em redução na polinização e aumento no aborto de botões florais (PLINE et al, 2002). NEWHOUSE et al (1991) relatam que os herbicidas dos grupos químicos das sulfoniluréias e imidazolinonas representam grupos de interesse na introdução de resistência em culturas, pois possuem várias características favoráveis como bom espectro de controle, baixo impacto ambiental, baixa toxicidade aos mamíferos, flexibilidade de aplicação e registro em vários países.…”

Section: Aspectos Ambientaisunclassified

“…Essa fitotoxicidade ocorre em função de diferenças nas características agronômicas de cada híbrido e na adaptabilidade em diferentes ecossistemas, além de seletividade diferenciada para diferentes herbicidas do referido grupo químico. Assim, pode-se concluir que alguns híbridos apresentam diferentes graus de resistência cruzada aos herbicidas do grupo das imidazolinonas (OWEN, 1998).…”

Section: Milhounclassified

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Plantas transgênicas resistentes aos herbicidas: situação e perspectivas

Monquero

2005

Bragantia

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RESUMOOrganismos geneticamente modificados (OGMs) ou transgênicos podem ser plantas, animais ou microorganismos que tiveram no seu material genético a introdução de DNA proveniente de outro organismo. Em alguns casos, esse organismo poder ser outro individuo da mesma espécie, ou o mais comum, de outra espécie com o qual não há cruzamento natural. O uso dessa técnica no melhoramento de plantas permitirá aumentar a produção, reduzir perdas na pós-colheita, obter culturas mais tolerantes ao estresse ambiental, obter culturas que usem mais eficientemente nitrogênio e fósforo; aumentar o valor nutricional dos alimentos; obter plantas resistentes a herbicidas, pragas e ou doenças; desenvolver alternativas para indústrias como as de combustíveis e farmacêuticas. Alguns consumidores acreditam que OGM não é natural e que o melhoramento convencional é melhor, pois segue os princípios naturais de seleção ou usa mutações naturais. Entretanto, é possível e muito comum obter combinações indesejáveis de genes através do melhoramento tradicional. Com relação a culturas resistentes a herbicidas, várias preocupações podem ser destacadas. Essas incluem: (a) deriva de herbicida para vegetação suscetível vizinha à cultura tolerante; (b) cultura resistente ao herbicida pode tornar-se planta daninha de difícil controle; (c) uso ilegal de sementes; (d) reação pública negativa à engenharia genética; (e) escape de genes para espécies nativas e (f) seleção de biótipos resistentes ou de espécies tolerantes ao herbicida utilizado. A geração dos organismos geneticamente modificados tem sido alvo de polêmica e discussão nos diversos segmentos da sociedade. Porém, não se deve generalizar o uso dos transgênicos, pois cada um deve ser analisado quanto às suas vantagens, desvantagens e contribuição à melhoria da qualidade de vida.

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Molecular basis of resistance to acetolactate synthase-inhibiting herbicides inSisymbrium orientaleandBrassica tournefortii

1999

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Three Australian Sisymbrium orientale and one Brassica tournefortii biotypes are resistant to acetolactate synthase (ALS)‐inhibiting herbicides due to their possession of an ALS enzyme with decreased sensitivity to these herbicides. Enzyme kinetic studies revealed no interbiotypic differences within species in Km (pyruvate) (the substrate concentration at which the reaction rate is half maximal) but a greater Vmax (the rate when the enzyme is fully saturated with substrate) for two of the resistant S orientale biotypes over susceptible levels. F1 hybrids from reciprocal crosses between resistant and susceptible biotypes of S orientale showed an intermediate response to chlorsulfuron compared to the parental plants. ALS herbicide resistance in S orientale segregated in a 3:1 (resistant:susceptible) ratio in F2 plants with a single rate of chlorsulfuron, indicating that resistance is inherited as a single, incompletely dominant nuclear gene. Two regions of the ALS structural gene known to vary in ALS‐resistant biotypes were amplified and sequenced. Resistant S orientale biotypes NS01 and SS03 contained a single nucleotide substitution in Domain B, predicting a Trp (in susceptible) to Leu (in resistant) amino acid change. Two adjacent nucleotide substitutions (CCT to ATT) predicting a Pro (in susceptible) to Ile (in resistant) change in the primary amino acid sequence were identified in Domain A of resistant S orientale biotype SS01. Likewise, a single nucleotide substitution at the same site in the resistant B tournefortii biotype predicts a Pro (in susceptible) to Ala (in resistant) substitution. No other interbiotypic nucleotide differences predicted amino acid changes in the sequenced regions, suggesting that the amino acid substitutions reported above are responsible for resistance to ALS‐inhibiting herbicides in the respective biotypes. © 1999 Society of Chemical Industry

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Mutations in corn (Zea mays L.) conferring resistance to imidazolinone herbicides

Cited by 115 publications

References 24 publications

Tolerance to Imidazolinone Herbicides in Wheat

Tolerance to Imidazolinone Herbicides in Wheat

Plantas transgênicas resistentes aos herbicidas: situação e perspectivas

Molecular basis of resistance to acetolactate synthase-inhibiting herbicides inSisymbrium orientaleandBrassica tournefortii

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