PLANT SELF-DEFENSE SYSTEMS AGAİNST NEGATİVE FACTORS

From a biological perspective, stress is considered as any change in the external environmental conditions that weakens the normal development of a plant or changes it in a negative direction [2]. Biotic (pathogen, competition with other organisms, etc.) and abiotic (drought, salinity, radiation, high and low temperatures, etc.) stresses cause changes in the physiological activity of plants, weaken the biosynthesis process in the cell, disrupt normal life activities and ultimately can cause the death of plants. Drought stress, being one of the most widespread environmental factors affecting development and productivity, induces many physiological, biochemical and molecular responses in plants and plants form tolerant mechanisms to adapt to unfavorable environmental conditions. The study of these mechanisms is of great theoretical and experimental importance in the creation of plant varieties and forms resistant to unfavorable external environmental factors. All living organisms, including plants, are constantly exposed to the environmental factors they live in during their life activity. The responses of organisms to external environmental factors are of a general nature. These factors can be changes in natural conditions (drought, salinity, radiation, high and low temperatures, etc.), infectious factors (viruses, bacteria, etc.) or other anthropogenic factors. In order for plants to survive and continue their life activity, they must adapt to changed external environmental factors. In the process of evolution, various ways of adaptation of organisms to external environmental factors have arisen, but the mechanisms for perceiving and defending against these factors have not yet been fully elucidated.