Protective Responses Induced by Chiral 3-Dichloroacetyl Oxazolidine Safeners in Maize (Zea mays L.) and the Detoxification Mechanism

Abstract

Herbicide safeners selectively protect crops from herbicide injury while maintaining the herbicidal effect on the target weed. To some extent, the detoxification of herbicides is related to the effect of herbicide safeners on the level and activity of herbicide target enzymes. In this work, the expression of the detoxifying enzyme glutathione S-transferase (GST) and antioxidant enzyme activities in maize seedlings were studied in the presence of three potential herbicide safeners: 3-dichloroacetyl oxazolidine and its two optical isomers. Further, the protective effect of chiral herbicide safeners on detoxifying chlorsulfuron in maize was evaluated. All safeners increased the expression levels of herbicide detoxifying enzymes, including GST, catalase (CAT), and peroxidase (POD) to reduce sulfonylurea herbicide phytotoxicity in maize seedlings. Our results indicate that the R-isomer of 3-(dichloroacetyl)-2,2,5-trimethyl-1,3-oxazolidine can induce glutathione (GSH) production, GST activity, and the ability of GST to react with the substrate 1-chloro-2,4-dinitrobenzene (CDNB) in maize, meaning that the R-isomer can protect maize from damage by chlorsulfuron. Information about antioxidative enzyme activity was obtained to determine the role of chiral safeners in overcoming the oxidative stress in maize attributed to herbicides. The interaction of safeners and active target sites of acetolactate synthase (ALS) was demonstrated by molecular docking modeling, which indicated that both isomers could form a good interaction with ALS. Our findings suggest that the detoxification mechanism of chiral safeners might involve the induction of the activity of herbicide detoxifying enzymes as well as the completion of the target active site between the safener and chlorsulfuron.

Enhanced Solubility, Stability, and Herbicidal Activity of the Herbicide Diuron by Complex Formation with β-Cyclodextrin

“…For the control group, water was sprayed in a bowl with the same volume as the β -CD solution. The growth index of Echinochloa crusgalli seedlings, including root length, plant height, and fresh weight, was measured after 10 days of incubation in the incubator [17,18]. The measurement procedure was repeated three times.…”

Phi class glutathione transferases as molecular targets towards multiple-herbicide resistance: Inhibition analysis and pharmacophore design

“…Plant GSTs have been identified as major mediators of metabolic resistance to herbicides through their catalytic activity to conjugate the tripeptide glutathione (GSH) to a wide range of herbicides (Busi et al, 2018;Gaines et al, 2020;Gao et al, 2019;Nakka et al, 2017). A specific phi class glutathione transferase (MHR-GSTF) that also exhibits high glutathione peroxidase activity has been identified as a major factor (Cummins et al, 1999(Cummins et al, , 2013Georgakis et al, 2020;Pégeot et al, 2017) that confers resistance against multiple herbicides through multiple mechanisms (Tétard-Jones et al, 2018).…”

Interação do tratamento de sementes e da mistura em tanque de herbicidas na seletividade para o arroz irrigado

“…Os sintomas de fitointoxicação observados em plantas tolerantes deve-se ao dano nas membranas celulares por peroxidação lipídica, resultando em extravasamento do conteúdo celular para o meio e necrose dos tecidos (KRUSE et al 2006). Além dos efeitos descritos, as EROs podem reagir com inúmeros componentes celulares, causando reações de oxidação em cascata que resultam na inativação de enzimas, degradação de proteínas, danos ao DNA e pigmentos celulares (GAO et al 2019).…”

“…A mitigação da elevada fitointoxicação promovida pelo estresse oxidativo resultante de tratamentos herbicidas pode ser conseguida através de medidas que favoreçam a síntese de compostos antioxidantes, como as enzimas superóxido dismutase (SOD), ascorbatoperoxidase (APX), glutationaperoxidase (GPX), guaiacol peroxidase (GPOX) e catalase (CAT); também inclui aqueles compostos não enzimáticos, como tocoferol (vitamina E), caroteno, ascorbato (vitamina C), e glutationa (GSH) (GAO et al 2019). Neste sentido, o tratamento de sementes com fungicidas do grupo químico das estrobilurinas poderia ser uma alternativa a ser empregada (KANUNGO & JOSHI 2014).…”