Nitrate reductase and glutamine synthetase activity in coffee leaves during fruit development
Autor: | Milton Ferreira Moraes, André Rodrigues dos Reis, José Laércio Favarin, Eurípedes Malavolta, Luiz Antonio Gallo, José Lavres Junior |
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Rok vydání: | 2009 |
Předmět: |
nitrogen assimilating enzymes
biology Coffea arabica food and beverages Soil Science engineering.material Nitrate reductase Enzyme assay Glutamine chemistry.chemical_compound Horticulture Nitrate chemistry Glutamine synthetase Botany engineering biology.protein Fertilizer Agronomy and Crop Science Plant nutrition nitrogen fertilizer |
Zdroj: | Revista Brasileira de Ciência do Solo v.33 n.2 2009 Revista Brasileira de Ciência do Solo Sociedade Brasileira de Ciência do Solo (SBCS) instacron:SBCS ResearcherID |
ISSN: | 0100-0683 |
Popis: | Nitrate reductase is the first enzyme in the pathway of nitrate reduction by plants, followed by glutamine synthetase, which incorporates ammonia to glutamine. The purpose of this study was to evaluate the nitrate reductase and glutamine synthetase activity, total soluble protein content, N and Ni content in coffee leaves during fruit development under field conditions to establish new informations to help assess the N nutritional status and fertilizer management. The experimental design was in randomized complete blocks, arranged in a 3 x 6 factorial design, with five replications. The treatments consisted of 3 N rates (0 - control, 150 and 300 kg ha-1) and six evaluation periods (January, February, March, April, May, and June) in six-year-old coffee (Coffea arabica L.) plants of Catuaí Vermelho IAC 44 cv. The nitrate reductase and glutamine synthetase activities, leaf soluble protein, and N concentrations increased linearly with the N rates. During fruit development, the enzyme activity, leaf soluble protein and N content decreased, due to the leaf senescence process caused by nutrient mobilization to other organs, e.g, to the berries. Leaf Ni increased during fruit development. Beans and raisin-fruits of plants well-supplied with N had higher Ni contents. Enzyme activities, total leaf N and leaf soluble protein, evaluated during the green fruit stage in March, were significantly correlated with coffee yield. These variables can therefore be useful for an early assessment of the coffee N nutritional status as well as coffee yield and N fertilization management. |
Databáze: | OpenAIRE |
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