Determination of physiological and molecular responses in beans (phaseolus vulgaris L.) treated with cadmium

Various anthropogenic activities such as mining, modern agricultural practices and industrialization cause increases in the concentration of heavy metals in soil, water and air and have long-term harmful effects on the environment we live in. Cadmium (Cd) is an important environmental pollutant that has emerged recently due to its widespread industrial use. Cd toxicity affects the metabolism of plants from germination to yield suppression. In this context, in the thesis study, it was attempted to understand the metabolic and molecular responses of bean (Phaseolus vulgaris L.) plant to different cadmium applications. A commercial variety (Gina) and a geographically indicated local variety (Gevaş) were selected and depending on the preliminary trial results according to the randomized plots trial design under climate chamber conditions, 10, 20, 40 and 80 ppm cadmium concentrations were applied to these varieties as irrigation water. In order to determine the effects of heavy metal, morphologically; root, stem length, fresh dry weight, physiologically; chlorophyll, carotenoid, phenolic, flavonoid and DPPH activities as well as stomatal apertures, cadmium values in soil and organs, and molecular expression status of 5 different gene regions were evaluated. When the data analyses were evaluated, it was seen that Gina and Gevaş varieties generally exhibited quite different and variable responses depending on the concentration. While increasing cadmium concentration in Gina caused a decrease in chlorophyll and phenolic amounts, it was determined that it caused an increase in Gevaş variety. It was observed that stomatal apertures and sizes decreased especially in 80 ppm application. Due to increasing cadmium concentration, especially in 40 and 80 ppm applications, it was determined that Gina variety accumulated cadmium more in roots and stems than leaves, while Gevaş variety generally accumulated cadmium in leaves. In the analysis of gene expressions, WRKY, NAC, MTF, IRT and ABA 8H regions related to stress and cadmium pathways were studied. The expression changes in WRKY gene expressions were found to be at the same rates for both varieties. In other gene regions, differences were calculated depending on the concentration. It has been noted that there are significant differences in the responses to heavy metal stress between the Gevaş local variety grown in the Van-Gevaş region and the Gina commercial variety, which is also widely grown in our country. As a result of the analyses, it has been determined that the Gevaş bean really gives successful and effective responses to cadmium stress at both physiological and molecular levels and that the variety has the potential to be tolerant and resistant to heavy metal stress