Ação citoprotetora do óxido nítrico na germinação de arroz (Oryza sativa L.) e soja (Glycine max (L.)Merril)submetidas a estresse de alumínio
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Data
2007-02-26
Autores
Silva, Tatiana Kazue [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O alumínio é um metal pesado que causa problemas em 30-40% das terras cultiváveis do planeta, mais comumente nos trópicos, onde os solos são ácidos, e possui efeito tóxico direto sobre o metabolismo vegetal. Estudos recentes demonstram a atividade citoprotetora do radical livre óxido nítrico (NO) em plantas sob estresse de alumínio. O objetivo deste trabalho foi verificar a ação citoprotetora do NO em condições de estresse de alumínio durante a germinação de sementes de arroz. Para os tratamentos, foram utilizadas soluções de diferentes concentrações de nitroprussiato de sódio (SNP), como doadora de NO e para a simulação de estresse de alumínio foram utilizadas soluções de diferentes concentrações de sulfato de alumínio. O experimento foi conduzido em duas etapas. Para os tratamentos da primeira etapa do experimento foi utilizado solução de SNP nas concentrações 50, 100, 250, 500, 1000 e 1500 mmol.L-1 e soluções de sulfato de alumínio nas concentrações 10, 20, 30, 40, e 50 mmol.L-1 . Para o controle foi utilizado água destilada. Na segunda etapa do experimento foram utilizadas soluções de SNP 50 mmol.L-1 e de sulfato de alumínio 30 mmol.L-1 . As sementes foram submetidas a uma incubação por 18 h em água destilada (Grupo I) ou em solução de SNP (Grupo II) e em seguida foram transferidas para água destilada, solução de SNP ou solução de sulfato de alumínio. Foram realizadas avaliações de germinação diariamente, por 4 dias. Pode ser concluído que o NO causa estímulo da germinação de arroz nas fases iniciais deste processo, sendo mais evidente no período de 48 h de embebição. O maior incremento da germinação foi observado na concentração de 50 μmol.L-1 de SNP, ao passo que as concentrações de SNP acima de 500 μmol.L-1 causaram redução da germinação. Também foi possível detectar...
Aluminum is a heavy metal that causes problems in 30-40% of the planet’s arable land areas, more commonly in the tropics, where soils are acid, and has a direct toxic effect on plant metabolism. Recent studies have demonstrated the cytoprotective activity of free radical nitric oxide (NO) in plants under aluminum stress. The objective of this study was to verify NO cytoprotective action under aluminum stress conditions during germination of rice seeds. Sodium nitroprussiate solutions (SNP) at different concentrations were used in the treatments as NO donors, and aluminum sulfate solutions at different concentrations were used to simulate aluminum stress. The experiment was conducted in two steps. SNP solutions at concentrations of 50, 100, 250, 500, 1000, and 1500 mmol.L-1, and aluminum sulfate solutions at concentrations of 10, 20, 30, 40, and 50 mmol.L-1 were used in the treatments of the first step of the experiment. Distilled water was used as a control. In the second step of the experiment, we used a SNP solution at 50 mmol.L-1 and an aluminum sulfate solution at 30 mmol.L-1. The seeds were submitted to incubation for 18 h in distilled water (Group I) or in SNP solution (Group II) and were then transferred to distilled water, SNP solution, or aluminum sulfate solution. Germination evaluations were carried out daily, for 4 days. It can be concluded that NO stimulates rice germination at the initial stages of the germination process, which is more evident in the 48 h imbibition period. The greatest increase in germination was observed at the SNP concentration of 50 μmol.L-1, while SNP concentrations above 500 μmol.L-1 reduced germination. It was also able to detect that NO was capable to reduce soybean germination inhibition resulting from the aluminum stress effect... (Complete abstract click electronic access below)
Aluminum is a heavy metal that causes problems in 30-40% of the planet’s arable land areas, more commonly in the tropics, where soils are acid, and has a direct toxic effect on plant metabolism. Recent studies have demonstrated the cytoprotective activity of free radical nitric oxide (NO) in plants under aluminum stress. The objective of this study was to verify NO cytoprotective action under aluminum stress conditions during germination of rice seeds. Sodium nitroprussiate solutions (SNP) at different concentrations were used in the treatments as NO donors, and aluminum sulfate solutions at different concentrations were used to simulate aluminum stress. The experiment was conducted in two steps. SNP solutions at concentrations of 50, 100, 250, 500, 1000, and 1500 mmol.L-1, and aluminum sulfate solutions at concentrations of 10, 20, 30, 40, and 50 mmol.L-1 were used in the treatments of the first step of the experiment. Distilled water was used as a control. In the second step of the experiment, we used a SNP solution at 50 mmol.L-1 and an aluminum sulfate solution at 30 mmol.L-1. The seeds were submitted to incubation for 18 h in distilled water (Group I) or in SNP solution (Group II) and were then transferred to distilled water, SNP solution, or aluminum sulfate solution. Germination evaluations were carried out daily, for 4 days. It can be concluded that NO stimulates rice germination at the initial stages of the germination process, which is more evident in the 48 h imbibition period. The greatest increase in germination was observed at the SNP concentration of 50 μmol.L-1, while SNP concentrations above 500 μmol.L-1 reduced germination. It was also able to detect that NO was capable to reduce soybean germination inhibition resulting from the aluminum stress effect... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Fisiologia vegetal - Estudos experimentais, Arroz, Soja, Germinação, Aluminum, Germination, Soybean
Como citar
SILVA, Tatiana Kazue. Ação citoprotetora do óxido nítrico na germinação de arroz (Oryza sativa L.) e soja (Glycine max (L.)Merril)submetidas a estresse de alumínio. 2007. 53 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2007.