Biochemical and Molecular Characterization of Wheat Genotypes Under Drought Stress: Implications for Antioxidant Defense Mechanisms and Genomic Analysis

In abiotic stress factors, drought is a complex feature controlled by many genes. For this reason, drought stress effects should be investigated using molecular markers and biochemical characterization in wheat genotypes. Within the scope of this study; eight different wheat cultivars and two for control group including Gerek-79, known to be highly tolerant of drought, and sensitive Sultan-95 were grown during 40 days. After breeding, they were subjected to drought stress for 10 days. As a result of water deficiency stress, antioxidant amounts and antioxidant enzyme activities, which convert ROS into harmless components, are the most important resistance mechanisms against oxidative stress. Among the most effective anti-oxidative enzymes such as polyphenol oxidase (PPA), peroxidase (POD), ascorbate peroxidase (ASPX), catalase (CAT) levels were determined. The response of plants to stress can be described as changes in photosynthetic pigment, total protein, hydrogen peroxide, lipid peroxidation (MDA) and proline levels as well as antioxidant enzymes level. We also analyzed wheat genotypes with drought tolerance related SSR markers (Xwmc 89, Xwmc 118, Xwmc 304, Xgwm 337). Thus, the effect of molecular characterization on the analysis of biochemical changes under drought stress was evaluated. Suša je kompleksni stres, ki ga uravnavajo številni geni, kar pri genotipih krušne pšenice zahteva preučevanje molekularnih označevalcev in biokemičnih procesov. V to raziskavo je bilo vključenih osem genotiopov krušne pšenice in dve kontroli: na sušo tolerantna sorta Gerek-79 in občutljiva sorta sorta Sultan-95. Vse rastline so bile gojene 40 dni v standardnih razmerah in nato izpostavljene sušnemu stresu za 10 dni. Antioksidanti in antioksidacijski emcimi, ki nevtralizirajo aktivne zvrsti kisika (ROS) so ključni mehanizmi za odpravo oksidacijskega stresa. Izmerjene so bile vsebnosti polifenol oksidase (PPO), peroksidaze (POD), askorbat peroksidaze (APX) in katalaze (CAT). Analiza odziva rastlin na stres je obsegala še meritve sprememb v vsebnosti fotosinteznih pigmentov, celokupnih beljakovin, vodikovega peroksida, spremembe v peroksidaciji maščob (MDA) in v vsebnosti prolina. POD je pokazala največjo spremembo v aktivnosti med tem, ko je bila PPO najmanj prizadeta. Vsebnost klorofila b se je v stresnih razmerah povečala pri vseh sortah. Značilno se je po desetih dneh suše povečala vsebnost prolina kot označevalca abiotičnega stresa. Dodatno so bili v genotipih krušne