Effect of nitrogen on activity of peptide hydrolases and protein content in caryopses and flag leaf of barley in ontogenesis

St. Petersburg State Agrarian University, Peterburgskoe Shosse, 2, 196601, Pushkin, St. Petersburg, Russia

^* Corresponding author: r.gamzaeva@yandex.ru

Abstract

The aim of the research was to study the influence peculiarities of different levels of nitrogen nutrition on the activity of peptide hydrolases and protein content in ontogeny of barley plants.The paper discusses the content of total nitrogen, protein and the dynamics of activity of proteolytic enzymes during ontogenesis of barley plants. The activity of peptide hydrolases, the content of protein and total nitrogen were determined in four developmental phases in the flag leaf and forming caryopses of barley. The aim of the work was to determine the effect of different levels of nitrogen on the quantitative content of protein, the total amount of nitrogen, as well as on the activity of acidic and neutral peptide hydrolases. In the course of the research, the following features were revealed: 1. The content of total nitrogen and protein, as well as the activity of proteases, depended on the developmental phase and on the level of nitrogen nutrition; 2. Increasing doses of nitrogen contribute to a greater nitrogen outflow from flag leaves into the forming grain; 3. High nitrogen norms inhibit the activity of peptide hydrolases. 4. The highest rates of activity of acidic proteases were noted in the phase of full ripeness. 5. The total activity of peptide hydrolases increased in variants with a twoand three-fold nitrogen dose.