Protective action of nitric oxide in sesame seeds submitted to water stress

Abstract

-The objective in this work was to investigate the effect of nitric oxide (NO) like protective agent in sesame seeds submitted to different osmotic potentials. The treatments, in total of eight, were water (control), water plus sodium nitroprusside (SNP) and the other treatments with PEG 6000 and PEG 6000 plus SNP: -0.1 MPa, -0.1MPa +200 µM of SNP, 0.2 MPa, -0.2 MPa +200 µM of SNP, -0.3 MPa and -0.3 MPa, +200 µM of SNP. Were done the following determinations: germination, first count of germination, speed germination index, hypocotyl length, radicle length, dry mass of hypocotyl and radicle. It was quantified the activity of the antioxidative enzymes, superoxide dismutase, catalase, ascorbate peroxidase and total peroxidase. The experimental design was completely randomized with five replications. The water restriction reduced the germination of sesame seeds, however, the presence of nitric oxide (NO) due to the application of SNP, was beneficial, promoting increase in germination, vigor and seedlings. There was an increase of antioxidative enzymes activity in the period of 0 to 24 hours, demonstrating organization of antioxidative system in all long the time. The association of PEG 6000 to SNP, increased the activity of antioxidative enzymes, evidencing an efficient system of elimination of ROS formed during the exposition to water deficit.Index terms: Sesamum indicum L., sodium nitroprusside, vigor, germination, antioxidative system. Ação protetora do óxido nítrico em sementes de gergelim submetidas ao estresse hídrico RESUMO -O objetivo neste trabalho foi investigar o efeito do óxido nítrico como agente protetor em sementes de gergelim submetidas a diferentes potenciais osmóticos. Os tratamentos, no total de oito, foram: água (controle), água acrescida de nitroprussiato de sódio (SNP) e os demais tratamentos referentes às concentrações de PEG e PEG acrescido de SNP: 0,1MPa, 0,1MPa +200 µM de SNP, -0,2 MPa, -0,2MPa +200 µM de SNP, -0,3 MPa e -0,3 MPa, +200 µM de SNP. Foram feitas as seguintes determinações: germinação, primeira contagem de germinação, índice de velocidade de germinação, comprimento de hipocótilo, radícula e massa seca de hipocótilo e radícula, além da quantificação da atividade das enzimas superóxido dismutase, catalase, ascorbato peroxidase e peroxidases totais. O delineamento estatístico utilizado foi o inteiramente casualizado com cinco repetições. A restrição hídrica reduz a germinação de sementes de gergelim, entretanto, a presença de óxido nítrico (ON) proporciona aumento na germinação e vigor. Há aumento da atividade das enzimas do sistema antioxidante no período de 0 a 24 horas, demonstrando organização do sistema antioxidante nas sementes de gergelim. A associação do PEG-6000 ao SNP aumenta a atividade das enzimas antioxidantes evidenciando um eficiente sistema de eliminação de ERO durante a exposição ao estresse hídrico.Termos para indexação: Sesamum indicum L., nitroprussiato de sódio, vigor, germinação, sistema antioxidante.

Does the substrate affect the germination of soybean seeds treated with phytosanitary products?

“…The potential of -1.0 MPa was considered severe for E. involucrata seed germination (Inocente et al, 2019). Under higher water restriction, prolongation of the stationary phase of the imbibition process occurs (Pires et al, 2016).…”

Action of nitric oxide on the physiological potential and biochemical mechanisms of pea seeds

“…Like CAT, APX and POX are part of a group of peroxidases that act to neutralize H 2 O 2 by different routes of action (De Gara, 2004). The effect of NO/SNP on seeds has been reported in the activity of antioxidant enzymes in different species, such as in sesame seeds exposed to water stress, where SNP increased the activity of the antioxidant enzymes, proving to be an efficient system for elimination of ROS (Pires et al, 2016). In a similar manner, Pandey et al ( 2019) observed the importance of NO in chickpea germination through control of respiration and of ROS accumulation.…”