Dissertation for the Doctor of Philosophy degree 091 "Biology" (09 - Biology) - Institute of Cell Biology and Genetic Engineering - Kyiv, 2023.
The dissertation is devoted to the study of the relationship between damage to the genome under different types of irradiation and the stimulation of the release of pharmaceutical compounds of chamomile.
Due to the growing use of plants in official medicine, the variety of approaches to obtaining more medicinal substances from this natural raw material is also increasing. Along with the search for new species that have medicinal properties, the breeding of more productive varieties, the reorientation of the metabolism of organisms in the direction of increasing the substances necessary for practice is used. While genetic and metabolic engineering focuses on the genetic transformation of organisms to solve this issue, the experience of studying protective reactions to stressors indicates the possibility of using epigenetic mechanisms to reorient metabolism.
One of the effective approaches is the use of ionizing and UV-C irradiation. With acute and chronic exposure, there is a shift in metabolic processes towards the formation of substances of secondary metabolism, which include the majority of radioprotectors that have antioxidant, anticarcinogenic, immunomodulatory and anti-inflammatory effects and are used in pharmacology.
One of the main components of the development of biotechnology to increase the yield of medicinal substances from plant raw materials, in particular antioxidants, by using different types of irradiation, is the selection of genotypes with high sensitivity to the action of stress factors and the clarification of the interaction of molecular-genetic mechanisms that determine these effects. The study of these issues was carried out on six varieties of Matricaria chamomīlla of European selection from the collection of the Central Station of Medicinal Plants of the National Academy of Sciences of Ukraine (Lubny) and endemic ecotypes of seeds obtained from seed stations of Ukraine. Attention was directed to the molecular and genetic basis of stimulation in different genotypes of two technologically important characteristics - the yield of pharmaceutical raw materials (inflorescence) and the accumulation of antioxidants in it. Vegetation, field and laboratory studies were conducted. The methods of molecular-genetic analysis (ISSR-PCR and RAPD-PCR), biochemical methods of extracting antioxidants, methods of linear statistics and cluster analysis were used.
The implementation of the topic included a number of tasks that were performed in several stages.
The purpose of the first stage of the research was to establish, using the method of genetic markers, the connection between the sensitivity of genotypes to different types of radiation and the peculiarities of the organization of their genome. An assessment of polymorphism of the primary DNA structure of chamomile genotypes was carried out using ISSR-RAPD markers followed by a cluster analysis of the genetic distance between genotypes differing in stimulation of the productivity of pharmaceutical raw materials (inflorescence) and the accumulation of low molecular weight antioxidants flavonoids and phenols.
The analysis of the relationship between the efficiency of different types of irradiation on two indicators of increasing the productivity of different genotypes with the minisatellite polymorphism of their DNA showed ambiguous results. A very weak connection between the diversity of the two types of reaction of eight genotypes of chamomile with their DNA polymorphism according to ISSR markers was revealed. Not exclusively, no clear relationship between the initial (in control) polymorphism was found.
Meanwhile, a clear connection between DNA polymorphism by RAPD sequences and the productivity of pharmaceutical raw materials was revealed.
The studied eight genotypes are divided into three subclusters, two of which react significantly to UV-C irradiation, and one to X-ray irradiation.
The conducted study revealed the absence of a relationship between the stimulation of a certain type of irradiation of the productivity of pharmaceutical raw materials and the accumulation of antioxidants. Thus, only with X-ray irradiation of the Azulena and Goral varieties, both the yield of inflorescences and the content of antioxidants are stimulated at the same time. In the Perlyna lisostepu variety, the stimulation of pharmaceutical raw materials by UV-C irradiation is observed, while the increase in the content of flavonoids occurs with X-ray irradiation. In the Quedlinburg variety, stimulation of the yield of pharmaceutical raw materials occurs with X-ray irradiation, and stimulation of the productivity of antioxidants is observed with UV-C irradiation.
