Two-Dimensional Electrophoretic Analysis of Soluble Leaf Proteins of a Salt-sensitive (Triticum aestivum) and a Salt-tolerant (T. durum) Cultivar in Response to NaCl Stress
Abstract:In this research, 3-day-old etiolated wheat seedlings of Triticum aestivum L. cv. Ceyhan-99 (salt-sensitive) and T. durum Desf. cv. Fırat-93 (salt-tolerant) were grown in control and salt (150 mmol/L NaCl) treatments at a 15/25 ◦C temperature regime in the light for 12 days. Soluble proteins extracted from the first leaf tissues of two cultivars were analyzed by twodimensional (2-D) electrophoresis in order to detect NaCl-induced changes. The soluble leaf protein profiles of cultivars were observed to be similar. However, quantitative differences in 74 proteins were detected in the salt treatment group, compared to the control. Among the 74 protein spots, 14 were common for two cultivars. As a result of NaCl treatment, two low-molecular-weight (LMW) proteins (28.9 and 30.0 kDa) and one intermediate-molecular-weight (IMW) protein (44.3 kDa) in cv. Ceyhan-99 and six LMW proteins (18.6, 19.4, 25.7, 25.9, 26 and 27.6 kDa) in cv. Fırat-93 were newly synthesized. The newly synthesized proteins were specific to each cultivar. In the Fırat-93 cultivar, four proteins with LMW (24.8–27.9 kDa) were completely lost in NaCl treatment. Moreover, these four protein spots were not observed in both protein profiles of cv. Ceyhan-99. Most of these proteins were in acidic character (pl <6.0–6.9) and low molecular weight (<31.6 kDa). It is suggested that the newly synthesized or completely lost LMWproteins may be important for cultivars differing in sensitivity towards NaCl.