Identification of plant growth promoting bacteria from Kaya Dağarcığı and Çam Dağarcığı endemic plants

Due to the increase in the world population, it is predicted that current food production will no longer be sufficient to feed people, and increasing agricultural productivity is a very important factor in meeting nutritional needs. Nowadays, however, biotic (pathogens, weeds, etc.) and abiotic (salinity, drought, etc.) stress factors are leading to a decline in agricultural productivity and quality. In addition, chemicals used unconsciously to increase agricultural productivity led to environmental pollution, disruption of the natural balance and damage to microorganisms. Various strategies and approaches are required to meet the increasing demand for food mentioned above. Bacteria are vital components of the soil and are involved in many biological processes such as nutrient transformation in the soil ecosystem. Bacteria contribute to plant development through many mechanisms such as the production of phosphate, siderephore, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3 acetic acid (IAA), known as plant growth regulators, protection of plants from phytopathogens and degradation of xenobiotics (such as pesticides). These bacteria are found in parts of the plant such as roots, leaves and stems known as Plant Growth Promoting Bacteria (PGPB). Within the scope of this thesis study, endophytic bacteria and rhizobacteria were isolated from Cam Dagarcıgı (Noccaea cariensis) Parolly, Nordt & Aytac and Kaya Dagarcıgı Aytaç (Noccaea camlikensis), Nordt & Paroly plants grown in serpentine soil. The siderophore production, phosphate solubilisation capacity, ACC deaminase activity, and IAA production capacity of these isolated bacteria were investigated and the PGPB property of the bacteria was evaluated. Additionally, most of these bacteria were found to be resistant to the antibiotics imipenem, tetracycline, kanamycin, and chloramphenicol, as well as to the heavy metals nickel, aluminium, chromium, and copper. As a result of the tests, 49 colonies with PGPB characteristics were selected and their molecular identification was carried out by DNA sequence analysis of the 16S rRNA gene regions and by laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF) of the proteins belonging to the same region. As a result of the identification, it was determined that the isolated bacteria were found to belong to the genera Pseudomonas, Pantoea, Peribacillus, Priestia, Bacillus, and Gottfriedia.