2.6. Real-time RT-PCR assays
To evaluate mRNA level expression, real-time RT-PCR assays were prepared using the Rotor Gene 3000 real-time thermal cycler(Corbett Life Science Co.) at the laboratory of Floriculture Section,Leibniz University Hannover, Germany. The PCR reaction mixture was made up to a volume of 20 L containing 10 ng of cDNA tem-plate, 150 M of each dNTP, 0.25 M forward primer, 0.25 Mreverse primer (Table 1), 1 U of Taq DNA polymerase (Axon Co.),5 mM MgCl2, 10 mM Tris-HCl and 50 mM KCl. PCR Amplification was monitored via intercalation of SYBR®Green (Roche Applied Science Co.) added to the reaction mixture in each tube. After 3 min of incubation at 94◦C, the cDNA was amplified by 40 three-step cycles: 30 s at 95◦C, 1 min at 61◦C, and 2 min at 72◦C. Each specific gene expression was quantified by normalization to -actin, a housekeeping gene, which concomitantly runs with specific genes’ primers. Specificity of the PCR amplification reaction was checked with a melting curve analysis (from 70 to 94◦C) following the final cycle, at the end of real-time PCR (Ahmadi et al., 2008).