The Effect of Reni Products on Enzymatic Activity of Nitrogen Metabolism in Garden Peas

N. POPOV1, A. DZIMOTUDIS1, S. KRASTEV1 and S. KALAPCHIEVA2

1 Agricultural University, BG - 4000 Plovdiv, Bulgaria
2 Maritsa Institute of Vegetable Crops, BG - 4003 Plovdiv, Bulgaria

Abstract

POPOV, N., A. DZIMOTUDIS, S. KRASTEV and S. KALAPCHIEVA, 2010. The effect of reni products on enzymatic activity of nitrogen metabolism in garden peas. Bulg. J. Agric. Sci., 16: 609-614

The aim of the present study was to establish the effect of two products of regulating effect (RENI and RENI A) on the activity of some major enzymes of nitrogen metabolism in garden peas at the stages of active nitrogen fixation. The investigations were carried out with garden pea plants of Vyatovo cultivar, grown in soil pot experiments (each plastic bucket of 5 l volume containing 3 kg of air dry soil). The experimental variants were: 1. Control – untreated, 2. Treated with RENI, 3. Treated with RENI À. Treatment was applied only once at the stage of buttoning and the first analyses were made 7 days after treatment. Treatment of garden peas with RENI products increased the activity of the enzymes nitrogenase, glutamine synthetase and asparagine synthetase in the plant roots. The highest activities were reported at the stage of mass flowering, which is a precondition for extending the process of symbiotic nitrogen fixation. The reported values ranged within 3.14 – 11.75 µmol/h/plant for nitrogenase; 33 – 90 µmol/h/g/ for glutamine synthetase; 28 – 88 µmol/h/g/ for asparagine synthetase. A positive interaction was established between nitrogenase activity (directly related to biological nitrogen fixation) and glutamine synthetase and asparagine synthetase activities (directly related to the uptake of the reduced nitrogen) after treatment with the products RENI. Treatment with the products RENI and RENI A decreased nitrate reductase activity in the leaves at all the studied stages and in the roots – at the buttoning stage. The effect of the action of both substances was different – RENI reduced nitrate reductase activity to a greater degree and at the same time, it increased nitrogenase, glutamine synthetase and asparagine synthetase activities also to a greater degree.

Key words: peas, nitrogen metabolism, nitrogenase, glutamine synthetase, asparagine synthetase

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