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The effects of silver nitrate on Cicer arietinum L. (C3) and Zea mays (C4) plants
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Os nanomateriais foram desenvolvidos há várias décadas e implementados numa ampla
gama de aplicações industriais. Atualmente, um dos nanomateriais mais utilizados são as
nanopartículas de prata (AgNPs), principalmente no setor agrícola.
As AgNPs podem ser produzidas por vários métodos. Um novo método de produção de
AgNPs é o uso de plantas ou extratos de plantas para a sua síntese, a chamada “síntese verde”,
revelando-se este método ser mais seguro, biológica e ambientalmente, quando comparado aos
métodos convencionais de produção - químicos ou físicos.
Todavia são escassos os estudos destas AgNPs, quando produzidas via síntese verde, nas
plantas C3 e C4. Tendo como objetivo preencher esta lacuna na ciência, esta investigação tem
por objetivo estudar o efeito do nitrato de prata (AgNO3) e das AgNPs, produzidas via síntese
verde usando Salvia officinalis, nas plantas C3 e C4. Como espécies de plantas C3 e C4 utilizouse Cicer arietinum L. (grão-de-bico) e Zea mays (milho), respetivamente. Este é o primeiro
estudo de que temos conhecimento que estudou ambos os tipos de plantas.
O estudo empírico foi conduzido no âmbito do programa Erasmus +, na University of
Veterinary and Pharmaceutical Sciences, Brno, compreendendo duas etapas. Na primeira etapa,
estudou-se o efeito do AgNO3 no grão-de-bico e no milho. Numa segunda etapa, delineou-se a
experiência para o estudo do efeito das AgNPs no mesmo tipo de plantas. Só foi possível
recolher e tratar os resultados empíricos relativos à primeira etapa (devido à interrupção da
investigação na sequência da pandemia COVID-19).
Os resultados empíricos obtidos evidenciam que os iões de prata são benéficos para a
germinação de ambos os tipos de plantas, sendo o nível de concentração mais benéfico o de 50
mg/L. Este resultado indicia que altas concentrações de AgNO3 podem causar stress oxidativo
e inibição do crescimento, levando à morte celular das plantas.
Com referência ao efeito das AgNPs, os resultados expectáveis com base na literatura,
sugerem que a toxicidade das AgNPs é menor do que a de AgNO3, pois não há acúmulo direto
de iões de prata. Assim, é possível gerar menos espécies reativas de oxigénio, menos efeitos
negativos nos parâmetros fotossintéticos e obter resultados ainda melhores na germinação das
plantas. Relativamente aos metabolitos secundários das plantas, a literatura não é consensual.
Nanomaterials went into development several decades ago and since implemented across a wide range of industrial applications. Nowadays, silver nanoparticles (AgNPs) represent one of the most commonly used nanomaterials, especially in the agricultural sector. There are several methods for producing AgNPs. A new AgNPs production method involves the usage of plants or plant extracts for their synthesis that termed “green synthesis”, which proves to be biologically and environmentally safer, when compared to conventional production methods via chemical or physical means. However, there are only scarce studies about the effects of AgNPs on C3 and C4 plants when produced via green synthesis. In order to fill this gap, this project aims to study the effect of silver nitrate (AgNO3) and AgNPs, produced via green synthesis using Salvia officinalis, on C3 and C4 plants. As C3 and C4 plant species, we made recourse to Cicer arietinum L. (chickpeas) and Zea mays (maize), respectively. To the best of our knowledge, this is the first research to study both types of plants. The empirical study, conducted under the Erasmus + program at the University of Veterinary and Pharmaceutical Sciences, Brno, involved two steps. The first studied the effect of AgNO3 on chickpeas and maize. In a second stage, the experiment was outlined to study the effect of AgNPs on the same plant types. It was only possible to collect and analyse the empirical results relating to the first step (due to the suspension of the research caused by the COVID-19 pandemic). The empirical results obtained demonstrate how silver ions are beneficial for the germination of both types of plants, with the most beneficial concentration level being 50 mg/L. Furthermore, these results indicate how high concentrations of AgNO3 may cause oxidative stress and the inhibition of growth, leading to cell death in plants. With reference to the effects of AgNPs, the results expected according to the literature indicate a lower level of toxicity for AgNPs than for AgNO3 as there is no direct accumulation of silver ions. Applying AgNPs makes it possible to generate fewer reactive oxygen species, less negative effects in terms of the photosynthetic parameters and obtaining even better results for plant germination. Regarding the secondary metabolites of plants due to the effect of AgNPs, the literature does not display any consensual position.
Nanomaterials went into development several decades ago and since implemented across a wide range of industrial applications. Nowadays, silver nanoparticles (AgNPs) represent one of the most commonly used nanomaterials, especially in the agricultural sector. There are several methods for producing AgNPs. A new AgNPs production method involves the usage of plants or plant extracts for their synthesis that termed “green synthesis”, which proves to be biologically and environmentally safer, when compared to conventional production methods via chemical or physical means. However, there are only scarce studies about the effects of AgNPs on C3 and C4 plants when produced via green synthesis. In order to fill this gap, this project aims to study the effect of silver nitrate (AgNO3) and AgNPs, produced via green synthesis using Salvia officinalis, on C3 and C4 plants. As C3 and C4 plant species, we made recourse to Cicer arietinum L. (chickpeas) and Zea mays (maize), respectively. To the best of our knowledge, this is the first research to study both types of plants. The empirical study, conducted under the Erasmus + program at the University of Veterinary and Pharmaceutical Sciences, Brno, involved two steps. The first studied the effect of AgNO3 on chickpeas and maize. In a second stage, the experiment was outlined to study the effect of AgNPs on the same plant types. It was only possible to collect and analyse the empirical results relating to the first step (due to the suspension of the research caused by the COVID-19 pandemic). The empirical results obtained demonstrate how silver ions are beneficial for the germination of both types of plants, with the most beneficial concentration level being 50 mg/L. Furthermore, these results indicate how high concentrations of AgNO3 may cause oxidative stress and the inhibition of growth, leading to cell death in plants. With reference to the effects of AgNPs, the results expected according to the literature indicate a lower level of toxicity for AgNPs than for AgNO3 as there is no direct accumulation of silver ions. Applying AgNPs makes it possible to generate fewer reactive oxygen species, less negative effects in terms of the photosynthetic parameters and obtaining even better results for plant germination. Regarding the secondary metabolites of plants due to the effect of AgNPs, the literature does not display any consensual position.
Descrição
Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, 2020, Universidade de Lisboa, Faculdade de Farmácia.
Palavras-chave
Silver nanoparticles Silver nitrate C3 plants C4 plants Green synthesis Mestrado integrado - 2020