Efeito da disponibilidade de nitrato em solução nutritiva sobre a absorção de nitrogênio e atividade enzimática de duas cultivares de arroz

Santos, André Marques dos; Bucher, Carlos Alberto; Stark, Elvia Mariam Lis Martinez; Fernandes, Mânlio Silvestre; Souza, Sônia Regina de

doi:10.1590/s0006-87052009000100023

Cited by 6 publications

(3 citation statements)

References 17 publications

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“…However, in that study the author did not analyze the quantity of the nutrient in the petioles. Santos et al (2009) concluded that in rice, flag leaf and leaf 2 act as preferential sites of N storage. Concentration analysis of N-NO 3 -per pot (Figure 3a, 4b) showed a reduction of the dilution effect and allows stating that the petiole really was the main organ for storing N, for both forms of the nutrient, when supplied at a dose of 0.2 mmol L -1 .…”

Section: Resultsmentioning

confidence: 99%

Soluble fractions and kinetics parameters of nitrate and ammonium uptake in sunflower ("Neon" Hybrid)

Alves

Torres

Fernandes

et al. 2016

Revista Ciência Agronômica

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-Sunflower plants are source of oilseeds with great importance for agroenergy. Nitrogen deficiency is considered one of the factors limiting growth and yield. The objective of this study was to assess the nitrogen uptake (high and low supply of nitrate and ammonium) and to determine the uptake kinetics parameters (K m and V max ) of these ions in sunflower plants (Neon hybrid). The experiment was carried out in a growth chamber using a hydroponic system. The following treatments were applied: 0.2 and 2.0 mmol L -1 of N-NO 3 -and N-NH 4 + . The two kinetics parameters (K m and V max ) involved in the uptake of nitrate and ammonium were determined, as well as the soluble fractions (N-NO 3 -, N-NH 4 + , amino-N and sugars) and total N, in different plant tissues. The plants grown with ammonium showed higher V max than those cultivated with nitrate. High ammonium rates caused reduction of root volume and the plants supplied with 2.0 mmol L -1 of N-NO 3 -produced more biomass from the roots and aerial part. The highest concentrations of N-NO 3 -were found in the petioles. Analyzed together, the data suggest a greater potential for use of nitric-N as a nitrogen source for fertilization in the cultivation of sunflower. RESUMO -O girassol é uma oleaginosa de grande importância agroenergética e o nitrogênio é considerado um dos fatores limitantes para seu crescimento e produção. O objetivo deste trabalho foi avaliar a absorção de nitrogênio (alto e baixo suprimento de nitrato e amônio) e determinar os parâmetros cinéticos (K m e V max ) de absorção desses íons em plantas de girassol (híbrido Neon). O experimento foi conduzido em câmara de crescimento utilizando-se sistema hidropônico. Foram aplicados os seguintes tratamentos: 0,2 e 2,0 mmol L -1 de N-NO 3 -e N-NH 4 + . Foram determinados os parâmetros cinéticos (K m e V max ) da absorção de nitrato e amônio, bem como as frações solúveis -. N-NH 4 + , N-amino e açúcares) e N-total em diferentes tecidos das plantas de girassol. As plantas cultivadas com amônio exibiram maior V max quando comparadas com as cultivadas com nitrato. Altas doses de amônio provocaram redução no volume radicular e as plantas supridas com 2,0 mmol L -1 de N-NO 3 -produziram maior biomassa de raízes e parte aérea. Os maiores teores de N-NO 3 -foram encontrados nos pecíolos. Analisados em conjunto, os dados sugerem maior potencial de utilização de N nítrico como fonte de nitrogênio para a adubação nitrogenada no cultivo de girassol. Palavras-chave:Helianthus annuus L.. Oleaginosa. N-total. Nitrogênio.

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Section: Resultsmentioning

confidence: 99%

Soluble fractions and kinetics parameters of nitrate and ammonium uptake in sunflower ("Neon" Hybrid)

Alves

Torres

Fernandes

et al. 2016

Revista Ciência Agronômica

Self Cite

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“…Some plants, such as sunflower (Rocha et al, 2014) and rice (Santos et al, 2005;Santos et al, 2009;Santos et al, 2011) accumulate NO3 --N preferentially in the stem over other parts of the plant. Similarly, the tomato plants accumulated NO3 --N in the stem (Figure 5a), which suggests that the stem is the preferred compartment for the accumulation of NO3 --N.…”

Section: Acephala Applanata Species Complex (Pac)mentioning

confidence: 99%

Physiological changes in tomato colonized by dark septate endophytic fungi

Vergara

Araujo²,

Zilli

2023

RSD

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As is customary in mycorrhizae, the interaction between plant and dark septate endophytic (DSE) fungi can result in physiological changes in the host plant, which are still poorly understood. This study aimed to evaluate the physiological changes in tomato plants colonized by DSE fungi. Four DSE isolates previously identified through ITS phylogeny were inoculated on tomato seeds and compared to non-inoculated plants (control). Kinetic parameters (Vmax and Km) were calculated measuring the nitrate content in the nutrient solution. The contents of NO3--N, NH4+-N, amino-N, soluble sugars in the root, petiole, stem and leaf, and the contents of macronutrients in the shoot were determined. The plants inoculated with A101 and A105 exhibited (i) significant increases in the soluble sugar contents; (ii) increases in the contents of P, K, Mg and S; and (iii) increased dry biomass compared to control. The A103 inoculation was antagonistic when compared to the other treatments, leading to a higher influx of NO3--N in the plants, resulting in a higher amino-N and the lower soluble sugar content in the shoot. The physiological parameters of tomato varied depending on the inoculation, and the changes ranged from positive to negative depending on each isolate involved in the interaction.

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“…A nitrato redutase é a enzima responsável pela assimilação do N-NO 3 -pelas plantas (EPSTEIN; BLOOM, 2006;SANTOS et al, 2009). Neste contexto, o arroz, por ser uma planta hidrófila de ambiente reduzido, com predominância do nitrogênio na forma de amônio, tem dificuldade de sintetizar no primeiro mês de desenvolvimento a enzima nitrato redutase, o que pode explicar o baixo desenvolvimento inicial da cultura (MALAVOLTA, 1980).…”

Section: Introductionunclassified

Acidez do solo afetando concentração de micronutrientes, atividade da enzima nitrato redutase e produtividade em plantas de arroz de terras altas

Moro¹,

Crusciol²,

Cantarella³

et al. 2013

Sem. Ci. Agr.

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Efeito da disponibilidade de nitrato em solução nutritiva sobre a absorção de nitrogênio e atividade enzimática de duas cultivares de arroz

Cited by 6 publications

References 17 publications

Soluble fractions and kinetics parameters of nitrate and ammonium uptake in sunflower ("Neon" Hybrid)

Soluble fractions and kinetics parameters of nitrate and ammonium uptake in sunflower ("Neon" Hybrid)

Physiological changes in tomato colonized by dark septate endophytic fungi

Acidez do solo afetando concentração de micronutrientes, atividade da enzima nitrato redutase e produtividade em plantas de arroz de terras altas

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