The results of studies on the presence in the seeds of legumes and cereals of protein inhibitors that are active against animal proteinases (trypsin) and exogenous peptidases of phytopathogenic microorganisms are presented. It has been shown that secreted proteolytic enzymes of the studied phytopathogens are mainly represented by cysteine proteinases, to a lesser extent, serine and aspartane proteinases are present. It has been established that a close positive correlation between plant resistance to pathogens is observed not with well-known and widespread trypsin inhibitors, but with the activity of inhibitors directed against exogenous peptidases secreted by fungal pathogens of the genus Fusarium , Colletotrichum and Helminthosporium . The results obtained in the course of the work can be used in breeding and genetic studies on the creation of varieties and types of crops with increased resistance to pathogenic microflora and insect pests, as well as to create protective preparations.

The depressing effect of electromagnetic radiation from power lines on morphometric and biochemical indicators of winter wheat and wild plant species has been established.Levelling of the inhibitory effect of power lines was observed as far away from the radiation source.The role of components of proteolysis system and lectins in plant adaptation to stress was noted.

Pre-harvesting germination of grain causes a considerable loss and it is one of the reasons for the decline of sowing and technological properties of grain. In this regard, the aim of this work was to elucidate the role of hydrolytic enzymes in the grain crop sustainability to germination in the ear. The object of the study were di- and tetraploid forms of rye and hexaploid forms of triticale and secalotriticum. The research allowed to select a stable and productive form of cereals to evaluate the resistance to grain germination for assessment of resistance to germination of grain at the root. It is shown that the germination of the grain at the root is affected by the ploidy of rye and the type of cytoplasm from heteroplasmic triticale. It is shown different levels of activity of proteolytic and amylolytic enzymes in the studied genotypes of cereals. Winter triticale had a marked higher level of activity of neutral, alkaline protease and α-amylase. Variation in the level of BAPase activity is 7.15– 24.4 EA/g. a. d. m. and α-amylase activity – 92 –118.7 mg/ml∙h. It is shown the close correlation between the activity of alkaline BAPase, α-amylase and resistance to the cereal grain germination in the ear. Heterogeneity of an electrophoretical range of proteins at the studied genotypes of rye and triticale is shown. The obtained data make a contribution to clarification of the reasons underlying the resistance of cereal cultures to germination of grain at the root and open possibilities of identification of their markers for use in selection.

Galega orientalis Lam. is a fodder crop with a number of important traits, including the early beginning of vegetation, fast growth, high productivity and nutritiousness. For its cultivation, the doses of mineral N are reduced due to active symbiotic N-fixation, resulting in the decrease of nitrogen content in the fodder and livestock production. Lectins and proteinase inhibitors, as anti-nutrients, affect the fodder quality negatively. But the distribution and activity of proteolytic factors and lectins in Galega orientalis are not still clarified enough. We conducted the chemical investigation of leaves and seeds in 19 varieties and samples of Galega orientalis, originated mainly from the Eastern Europe. The activity of neutral and alkaline proteinases, tripsin inhibitors, lectin phytohemagglutination (PHA), as well as the protein content, composition and digestibility were examined. In total, the parameters varied significantly. The tested Galega varieties are the highly valuable fodder crop. Particularly, the content of proteins and essential amino acids in plants was high. The amino acid composition, necessary for the young growing animals, was revealed. In contrary, the content of tripsin inhibitors and lectins was not sufficient. The inhibitors were more active in the plants which began their vegetation later, and PHA was higher in the plants with early and intermediate beginning of vegetation. The characteristic electrophoretic patterns of seed proteins were also shown.

The response of the components of a protease-inhibitor system of legume and cereal crops to stress factors was studied. It was found that salinization, heavy metal ions, and phytopathogenic flora inhibit the activity of neutral, acidic, and alkaline proteases at early stages of seed germination, the degree of the inhibition of the endoprotease activity being dependent on the index of tolerance of legume and cereal crops. It was shown that, in response to unfavorable conditions, accumulation of trypsin inhibitors occurs, which is accompanied by the appearance of new protein components, as indicated by electrophoresis. The results confirm the presumption that serine protease inhibitors are involved in the response of plants to stress factors.

Specific features of changes in the contents of free and bound abscisic acid (ABA) and the activities of neutral and alkaline proteinases and trypsin inhibitory proteins were determined in the embryonic axis and cotyledons of the common bean (Phaseolus vulgaris L.) after drying. The changes in ABA content, observed following the loss of 5% seed weight, were regarded as an adaptive reaction to stress, whereas the corresponding changes after the loss of 10% of the seed’s weight, was regarded as a result of a pathological disturbance of ABA metabolism. Both drying modes had a negative effect on the state of the proteinase-inhibitory system, as was apparent from the disruption of the regular inverse correlation between the activities of proteinases and serine proteinase inhibitory proteins. A comparison of the dynamics of these characteristics with the buildup of water stress demonstrates an inverse correlation between the content of free ABA and the activity of the proteinases studied. This suggests a potential inhibitory effect of this hormone on the function of the hydrolases in question in the germinating seed.

Physicochemical and functional characteristics of plant protein proteinase inhibitors as antistress biopolymers were studied to determine the mechanisms for plant resistance to phytopathogens and to obtain disease-resistant cereal and leguminous cultures. The activity of trypsin, chymotrypsin, and subtilisin inhibitors varied in monocotyledonous and dicotyledonous cultures. Study varieties of leguminous and cereal cultures were shown to contain endogenous inhibitors specific to proteinases of phytopathogenic fungi Fusarium, Colletotrichum, Helminthosporium, and Botrytis. These inhibitors were characterized by species specificity and variety specificity. Protease inhibitors from buckwheat seeds inhibited proteases of fungal pathogens and suppressed germination of spores and growth of the fungal mycelium. Our results suggest that proteinaceous inhibitors of proteinases are involved in the protective reaction of plants under stress conditions.