Investigating the physiological and genetic impacts of Drought stress in Sunflower (Helianthus annuus)

With the increasing frequency and intensity of droughts due to climate change, understanding plant responses to water stress is crucial. This thesis investigates the physiological effects and underlying genetic mechanisms of drought stress in sunflowers (Helianthus annuus L.). The study employed two sunflower varieties: a drought-resistant and a drought-susceptible one, grown under controlled greenhouse conditions. A drought stress treatment was applied, followed by measurement of several physiological parameters such as Stomatal conductance, Chlorophyll content, Electron Transport Rate, etc. Afterwards, leaf samples were collected before and after the drought stress application for RNA extraction and the subsequent analysis of changes happening at the chromatin level. Thus, this research aims to understand the impacts of drought stress on sunflowers at the physiological and genetic/ epigenetic levels and identify potential mechanisms of drought tolerance. The findings will contribute to a deeper understanding of sunflower physiology under water stress and potentially guide the development and breeding of drought-resistant sunflower cultivars in the face of a changing climate.