Nanoencapsulation Enhances the Post-Emergence Herbicidal Activity of Atrazine against Mustard Plants

PLOS ONE, Dec 2019

Poly(epsilon-caprolactone) (PCL) nanocapsules have been recently developed as a modified release system for atrazine, an herbicide that can have harmful effects in the environment. Here, the post-emergence herbicidal activity of PCL nanocapsules containing atrazine was evaluated using mustard (Brassica juncea) as target plant species model. Characterization of atrazine-loaded PCL nanocapsules by nanoparticle tracking analysis indicated a concentration of 7.5 x 1012 particles mL-1 and an average size distribution of 240.7 nm. The treatment of mustard plants with nanocapsules carrying atrazine at 1 mg mL-1 resulted in a decrease of net photosynthesis and PSII maximum quantum yield, and an increase of leaf lipid peroxidation, leading to shoot growth inhibition and the development of severe symptoms. Time course analysis until 72 h after treatments showed that nanoencapsulation of atrazine enhanced the herbicidal activity in comparison with a commercial atrazine formulation. In contrast to the commercial formulation, ten-fold dilution of the atrazine-containing nanocapsules did not compromise the herbicidal activity. No effects were observed when plants were treated with nanocapsules without herbicide compared to control leaves sprayed with water. Overall, these results demonstrated that atrazine-containing PCL nanocapsules provide very effective post-emergence herbicidal activity. More importantly, the use of nanoencapsulated atrazine enables the application of lower dosages of the herbicide, without any loss of efficiency, which could provide environmental benefits.

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Nanoencapsulation Enhances the Post-Emergence Herbicidal Activity of Atrazine against Mustard Plants

July Nanoencapsulation Enhances the Post- Emergence Herbicidal Activity of Atrazine against Mustard Plants Halley Caixeta Oliveira 0 1 Renata Stolf-Moreira 0 1 Cláudia Bueno Reis Martinez 0 1 Renato Grillo 0 1 Marcelo Bispo de Jesus 0 1 Leonardo Fernandes Fraceto 0 1 0 1 Department of Animal and Plant Biology, UEL-University of Londrina , Londrina, Paraná, Brazil , 2 Department of Physiological Sciences, UEL-University of Londrina , Londrina, Paraná, Brazil , 3 Department of Biochemistry, Institute of Biology, UNICAMP-University of Campinas , Campinas, São Paulo , Brazil , 4 Department of Environmental Engineering, UNESP-Universidade Estadual Paulista , Sorocaba, São Paulo , Brazil , 5 Nano-Cell Interactions Laboratory, Institute of Biology, UNICAMP- University of Campinas , Campinas, São Paulo , Brazil 1 Editor: Maya Dimova Lambreva, National Research Council of Italy , ITALY Poly(epsilon-caprolactone) (PCL) nanocapsules have been recently developed as a modified release system for atrazine, an herbicide that can have harmful effects in the environment. Here, the post-emergence herbicidal activity of PCL nanocapsules containing atrazine was evaluated using mustard (Brassica juncea) as target plant species model. Characterization of atrazine-loaded PCL nanocapsules by nanoparticle tracking analysis indicated a concentration of 7.5 x 1012 particles mL-1 and an average size distribution of 240.7 nm. The treatment of mustard plants with nanocapsules carrying atrazine at 1 mg mL-1 resulted in a decrease of net photosynthesis and PSII maximum quantum yield, and an increase of leaf lipid peroxidation, leading to shoot growth inhibition and the development of severe symptoms. Time course analysis until 72 h after treatments showed that nanoencapsulation of atrazine enhanced the herbicidal activity in comparison with a commercial atrazine formulation. In contrast to the commercial formulation, ten-fold dilution of the atrazine-containing nanocapsules did not compromise the herbicidal activity. No effects were observed when plants were treated with nanocapsules without herbicide compared to control leaves sprayed with water. Overall, these results demonstrated that atrazine-containing PCL nanocapsules provide very effective post-emergence herbicidal activity. More importantly, the use of nanoencapsulated atrazine enables the application of lower dosages of the herbicide, without any loss of efficiency, which could provide environmental benefits. - Funding: This work was supported by the following sources of funding. LFF: Fundação de Amparo à Pesquisa do Estado de São Paulo (2013/12322-2), Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundunesp and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. RG: Fundação de Amparo à Pesquisa do Estado de São Paulo (2011/01872-6), CBRM: INCT-TA/CNPq (573949/2008-5). The funders had no role in study Introduction The growing demand for food production has been accompanied by increased use of herbicides to control weeds and maximize crop productivity. The indiscriminate use of herbicides has been associated with serious harm to the environment due to the contamination of water design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. resources and food, leading to deleterious effects on non-target plants, aquatic species, and sometimes humans [1]. It is therefore essential to develop technologies that minimize the negative impacts caused by these compounds, without hindering crop production. Nanotechnology, the term used to describe the processes of generation, manipulation, and use of nanomaterials, has emerged as a promising field that could help in alleviating problems associated with agrochemicals [2–7]. Nanomaterials have physicochemical characteristics that differ from those of the same material at the macroscopic scale, with an increase in specific surface area and changes in optical, magnetic, or mechanical properties [8]. There is a great variety of nanomaterials in the form of nanoparticles that can be used as carrier systems for bioactive compounds such as fertilizers and pesticides, with great potential for application in agricultural systems [3–7, 9]. Carrier systems based on nanoparticles provide modified release of bioactive agents, extending their duration of action and directing them more efficiently to target organisms [3]. In the case of herbicides, the use of nanoparticles could be beneficial in many respects, such as decreased contamination of water resources by leaching and less risk of harming nontarget organisms, including humans [2,5,6,10]. Atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) is an herbicide widely used for pre- and post-emergence control of weeds in maize, sorghum, and sugarcane cultures [11]. In common with other triazine herbicides, atrazine acts as an inhibitor of (...truncated)


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Halley Caixeta Oliveira, Renata Stolf-Moreira, Cláudia Bueno Reis Martinez, Renato Grillo, Marcelo Bispo de Jesus, Leonardo Fernandes Fraceto. Nanoencapsulation Enhances the Post-Emergence Herbicidal Activity of Atrazine against Mustard Plants, PLOS ONE, 2015, 7, DOI: 10.1371/journal.pone.0132971