Óxido nítrico na redução do estresse oxidativo induzido por herbicida em plantas de melão
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Data
2021-12-02
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Universidade Estadual Paulista (Unesp)
Resumo
O óxido nítrico (NO), além de possuir função sinalizadora em plantas, pode atuar como antioxidante. A finalidade de atuação deste composto ocorrerá de acordo com o tecido vegetal, idade da planta e tipo de estresse biótico ou abiótico. Assim, o objetivo do presente trabalho foi avaliar o efeito atenuante da aplicação do doador de NO, nitroprussiato de sódio (SNP), em plantas de melão submetidas ao estresse oxidativo pela aplicação do herbicida glufosinato de amônio na concentração de 1,75% de i.a. sobre parâmetros fitotécnicos e fisiológicos da cultura do melão. O experimento foi conduzido na Fazenda Experimental da Faculdade de Ciências Agronômicas da Universidade Estadual Paulista - UNESP, Campus de Botucatu - SP, em casa de vegetação. O delineamento experimental foi em blocos casualizados, composto por sete tratamentos: T1- Herbicida (glufosinato de amônio); T2- Herbicida + 15 µmol de SNP; T3- Herbicida + 30 µmol de SNP; T4- Herbicida + 60 µmol de SNP; T5- Herbicida + 120 µmol de SNP; T6- Herbicida + 240 µmol de SNP; T7- tratamento controle (sem aplicação de herbicida e SNP). Foram realizadas duas aplicações de SNP, sendo uma no período vegetativo (48 dias após o plantio - DAP) e outra no reprodutivo (67 DAP). As aplicações das diferentes concentrações de SNP foram realizadas quatro horas após as aplicações de glufosinato de amônio, momento este em que há o pico de produção das espécies reativas de oxigênio por ação do herbicida. Analisaram-se parâmetros biométricos, fisiológicos e produtivos da planta e frutos. O SNP produziu efeito benéfico nas plantas, reduzindo a porcentagem de dano foliar, de 18,5% para 7,5%, não influenciando na produção e qualidade de frutos. As concentrações de SNP empregadas não influenciaram nas variáveis de fluorescência da clorofila a e trocas gasosas. Já para as análises enzimáticas, a aplicação dos tratamentos influenciou na atividade do sistema antioxidante, promovendo aumento da atividade da enzima superóxido dismutase (SOD), catalase (CAT) e peroxidase (POD) aos 49 DAP, além de interferir no conteúdo endógeno de aminas biogênicas e de peróxido de hidrogênio (H2O2) nas folhas aos 68 DAP.
Nitric oxide (NO), in addition to having a signaling function in plants, can act as an antioxidant. The purpose of action of this compound will occur according to the plant tissue, plant age and type of biotic or abiotic stress. Thus, the aim of the present study was to evaluate the attenuating effect of the application of the NO donor, sodium nitroprusside (SNP), in melon plants subjected to oxidative stress by the application of the herbicide glufosinate ammonium at a concentration of 1.75% of ia on phytotechnical and physiological parameters of the melon crop. The experiment was carried out at the Experimental Farm of the Faculty of Agronomic Sciences of the Universidade Estadual Paulista - UNESP, Campus de Botucatu - SP, in a greenhouse. The experimental design was in randomized blocks, composed of seven treatments: T1- Herbicide (glufosinate of ammonium); T2- Herbicide + 15 µmol SNP; T3- Herbicide + 30 µmol SNP; T4- Herbicide + 60 µmol SNP; T5- Herbicide + 120 µmol SNP; T6- Herbicide + 240 µmol SNP; T7- control treatment (without herbicide and SNP application). Two SNP applications were carried out, one in the vegetative period (48 days after planting - DAP) and another in the reproductive period (67 DAP). The applications of the different concentrations of SNP were carried out four hours after the applications of glufosinate ammonium, when there is the peak of production of reactive oxygen species by the action of the herbicide. Biometric, physiological and productive parameters of the plant and fruits were analyzed. The SNP produced a beneficial effect on the plants, reducing the percentage of leaf damage from 18.5% to 7.5%, not influencing fruit production and quality. The SNP concentrations used did not influence the variables of chlorophyll a fluorescence and gas exchange. As for the enzymatic analyses, the application of the treatments influenced the activity of the antioxidant system, promoting an increase in the activity of the enzyme Superoxide Dismutase (SOD), catalase (CAT) and peroxidase (POD) at 49 DAP, in addition to interfering with the endogenous content of amines and hydrogen peroxide (H2O2) in the leaves at 68 DAP.
Nitric oxide (NO), in addition to having a signaling function in plants, can act as an antioxidant. The purpose of action of this compound will occur according to the plant tissue, plant age and type of biotic or abiotic stress. Thus, the aim of the present study was to evaluate the attenuating effect of the application of the NO donor, sodium nitroprusside (SNP), in melon plants subjected to oxidative stress by the application of the herbicide glufosinate ammonium at a concentration of 1.75% of ia on phytotechnical and physiological parameters of the melon crop. The experiment was carried out at the Experimental Farm of the Faculty of Agronomic Sciences of the Universidade Estadual Paulista - UNESP, Campus de Botucatu - SP, in a greenhouse. The experimental design was in randomized blocks, composed of seven treatments: T1- Herbicide (glufosinate of ammonium); T2- Herbicide + 15 µmol SNP; T3- Herbicide + 30 µmol SNP; T4- Herbicide + 60 µmol SNP; T5- Herbicide + 120 µmol SNP; T6- Herbicide + 240 µmol SNP; T7- control treatment (without herbicide and SNP application). Two SNP applications were carried out, one in the vegetative period (48 days after planting - DAP) and another in the reproductive period (67 DAP). The applications of the different concentrations of SNP were carried out four hours after the applications of glufosinate ammonium, when there is the peak of production of reactive oxygen species by the action of the herbicide. Biometric, physiological and productive parameters of the plant and fruits were analyzed. The SNP produced a beneficial effect on the plants, reducing the percentage of leaf damage from 18.5% to 7.5%, not influencing fruit production and quality. The SNP concentrations used did not influence the variables of chlorophyll a fluorescence and gas exchange. As for the enzymatic analyses, the application of the treatments influenced the activity of the antioxidant system, promoting an increase in the activity of the enzyme Superoxide Dismutase (SOD), catalase (CAT) and peroxidase (POD) at 49 DAP, in addition to interfering with the endogenous content of amines and hydrogen peroxide (H2O2) in the leaves at 68 DAP.
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Nitroprussiato de sódio, Enzimas antioxidativas, Cucumis melo L., Oxidação, Reguladores vegetais, Fisiologia vegetal, Sodium nitroprusside, Enzymes, Oxidation, Plant growth regulators, Plant physiology