Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Effects of Brassinosteroids on Barley (Hordeum Vulgare L.) Root Growth, Antioxidant System and Cell Division

Brassinosteroids (BRs) are endogenous plant hormones which have steroidal character and structure. BRs affect several biological processes, including cell expansion, xylem differentiation, seed germination, vegetative growth and promotion of apical dominance. Brassinosteroids confer resistance to plants against various abiotic stresses.

In this study, barley (Hordeum vulgare L. cv. Zafer 160) seeds were germinated in the dark at 25oC temperature in plant growth cabin, between filter papers which contain three different concentrations of BRs; 1 µM, 0.5 µM and 0.1 µM and using only distilled water for control groups. Effects of BRs on root growth were investigated and cytogenetic effects in root tips were also studied. Barley root tips obtained from germination of barley seeds during 48 hours were stained with iodine potassium iodide (IKI) and stained with 4',6-diamidino-2-phenylindole (DAPI) after the hydrolysation with 45 % acetic acid. Then they were analysed with fluorescent microscope (DM4000 B, Leica). Cell expansion and active cell division were observed in BR applied root tips. Preparations were made from germinated root tips with aceto orcein staining techniques. Root length of barleys which were germinated in solutions of 0.1 µM, 0.5 µM and 1 µM BR and number of cells in mitosis increased at significant level with respect to increasing dose of BR when compared with control group during 48 hours. In addition to this, effects of BRs on total soluble protein content, catalase (EC 1.11.1.6), peroxidase (EC 1.11.1.7) and superoxide dismutase (EC 1.15.1.1) activities were investigated in barley root tips. Comparing the control group, with the one which was treated with BR, showed a decrease in catalase and peroxidase activities. 0.5 and 1 µM concentration of BR caused decrease in superoxide dismutase activity comparing to untreated control. It was observed that the total soluble protein concentration was increasing at 0.1 and 0.5 µM BR and decreasing at 1 µM BR compared to untreated control. It is anticipated that data obtained from cytogenetic and histogenetic assays contribute to the understanding of BR mechanisms and root growth of barley and also could contribute to the malt industry.

KIĞ Cenk
Danışman : Prof.Dr. Güler TEMİZKAN

Anabilim Dalı : Moleküler Biyoloji ve Genetik

Mezuniyet Yılı : 2008

Tez Savunma Jürisi : Prof. Dr. Güler TEMİZKAN (Danışman)

Prof.Dr. Nermin GÖZÜKIRMIZI

Prof. Dr. Ayşegül TOPAL SARIKAYA

Prof. Dr. Sezai TÜRKEL

Prof. Dr. Ayşe ÖZER