Enlightening effects of biotic stress caused by Puccinia malvacearum in Malva spp. by biochemical and physiological parameters

Enlightening Effects of Biotic Stress Caused by Puccinia malvacearum in Malva spp. by Biochemical and Physiological Parameters Mehmet TEMEL Inonu University Graduate School of Natural and Applied Sciences Deparment of Biology ix + 76 2019 Supervisor: Professor Dr. Emel YİĞİT Co-Supervisor: Associate Professor Dr. Şanlı KABAKTEPE In this study, changes in pigment content which has an important role in photosynthesis, changes in malondialdehyde (MDA) which is an important indicator of lipid peroxidation, changes in peroxidase (POD) and ascorbate peroxidase (APX) which are known to be important in antioxidant system, changes in phenolic content and changes in dry weight were evaluated in Malva sylvestris (mallow) species which were and were not infected by Puccinia malvacearum (mallow rust). Pigment content were determined to be lower in the infected group in the samples taken in 2017-2018. In June and July, there was an increase in infected groups. The decrease in pigment content in the infected groups in May suggests that the degradation of some enzymes which are important in the metabolic pathway in pigment synthesis in plants that encounter stress factor for the first time. The increase observed in June and July may also be evidence of adaptation, probably due to the development of resistance in plants exposed to long-term stress. The increase in MDA content in infected groups was also considered as an indicator of oxidative stress in M. sylvestris. In addition, decrease in POD activity and increase in phenolic content were observed in the infected group. APX activity was also increased in infected groups. Again, the increase and decrease in the amount of dry matter in the infected groups were pointed to. When we evaluate our findings in general, we can say that Puccinia malvacearum caused important physiological and biochemical responses against biotic stress in Malva sylvestris and that Puccinia malvacearum caused oxidative stress. KEYWORD: Biotic Stress Puccinia malvacearum, Malva sylvestris, Pigmentation, Malondialdehyte, Peroxidase, Ascorbate Peroxidase, Phenolic Matter