ارزيابي الگوي تظاهر ژن هاي كربوهيدرات طي فرآيند سرمادهي با استفاده از روش Real-Time PCR كمي در گندم (Triticum aestivum L.em.Thell)

A Study on Expression Patterns of Carbohydrate Genes During Cold Acclimation Using Quantitative Real-Time PCR in Wheat (Triticum aestivum L. em.Thell)

Carbohydrate accumulation is one of the initial responses of plants to cold acclimation which occurs at a faster rate in tolerant varieties than in non tolerant ones, its accumulation also causing snow mold resistance. It is desirable to have varieties resistant to both freezing and snow mold. Hexokinase enzyme has a dual role in response to cold and snow mold stress. Hexokinase activity in freezing tolerant varieties reduces transcription of photosynthesis gene, inhibits further carbohydrate accumulation and reduces osmotic potential. Another group of enzymes are sugar transporters whose their activity increases during cold acclimation. In this research, expression patterns of hexokinase and sugar transporter genes isolated through SSH (Supression Subtractive Hybridization) were studied on Norstar as a freezing tolerant and snow mold susceptible variety and PI181268 as a less hardy, but snow mold resistant line. Crown tissues of the two varieties were sampled at 4°C in different periods of hardening and total RNA was extracted from crown tissues by Trizol method. cDNA was synthetized based on total RNA and used as template in Quantitative real-time PCR (QRT-PCR) method. Expression patterns of Contigl (Hexokinase) and Talt238M19 (sugar transporter) show dual role of these genes in cold and snow mold stresses. Finally, Contigl and Talt238M19 could be introduced as two important candidate genes which are effective in controling freezing and snow mold tolerance. Results indicated that Contigl and Talt417023 (sugar transporter) play a role only in cold stress.