TY - JOUR JF - MGJ JO - MGj VL - 11 IS - 2 PY - 2016 Y1 - 2016/8/01 TI - The effect of salinity in galactinol synthase (GAS) gene expression, antioxidant enzymes activity, carbohydrst and prolin in sistan melon landrace (Cucumis melo L.) TT - بررسی اثر شوری بر بیان ژن گالاکتینول سنتاز (GAS)، فعالیت آنزیم-های آنتی اکسیدان، میزان کربوهیدرات و پرولین در توده‌های بومی خربزه سیستان (Cu N2 - Salinity is a major problems in a wide area of Iran. Oligosaccharides of Raffinose family (RFOs) perform several physiological functions in plants such as accumulation of the suger in response to salt stress during seed forming. The synthesis of galactinol, mediated by galactinol synthase (GAS), is the first committed step in RFO formation. In order to resist to salinity, plants not only use osmotic regulation but also use a mechanism for increasing activity of antioxidant enzymes. In the present study, In order to determine GAS gene expression level, the role of catalase (CAT), ascorbate peroxidase (APX) and gayacol peroxidase (GPX), carbohydrat and proline levels in 3 selected Sistanian melon landraces (Cucumis melo L.) which are under salinity, a factorial arrangement in randomized complete block design with three replications experiment was done in Center of Agricultural Biotechnology of Zabol University. Four concentrations including 0, 50, 100 and 150 mM NaCl were used in this study. RNA was extracted from leaf samples and cDNA was designed using reverse transcription. The result showed that GAS gene expression increased by increasing salinity level from 0 to 150 mM. In comparison with control, in the highest level of salinity (150 Mm) GAS gene expression level increased 10.2-fold in Tashekandi landrace, 7.3-fold in Atashshirazi landrace and 19.79-fold in Sefidak landrace. The gene has the highest level of expression in Sefidak landrace comparing to other landraces. When salinity stress increased in three melon landraces of Tashekandi, Atashshirazi and Sefidak, antioxidant enzymes such as catalase (CAT) 85.9, 63.2 and 87.1 percent, ascorbate peroxidase (APX) 68.89, 36.48 and 92.81 percent, gayacol peroxidase (GPX) 89.25, 72.84 and 70.37 percent, carbohydrat 40.2, 84.4 and 92.8 percent and proline 86.6, 69.8 and 89.4 percent increased in comparison to control.It seems that expression of GAS gene synthesizes the sugars of raffinose family in three selected melon landraces in such condition which is effective for plant protection against the environmental stresses. This can help the plant for enduring under the salinity stress. It also provides the condition for plant endurance through the activity of two systems the enzyme activity increase and osmotic regulations. SP - 185 EP - 195 AU - فروزان حیدری, AU - صالحه نادری, AU - حمیده خواجه, AU - عباسعلی بهاری, AD - KW - Antioxidative enzyme KW - Galactinol synthase gene KW - Gene expression KW - Melon KW - salt stress UR - http://mg.genetics.ir/article-1-1417-en.html ER -