The expression pattern of genes encoding putative transcription factors in ethylene signal transduction was investigated, after treatment of tomato (Lycopersicon esculentum cv. UC-82) seedlings with solutions of differing NaCl concentration for 12, 24 and 48 h. The role of ethylene signalling in tomato seedlings adapting to salt stress is discussed. Le-EIL1 gene expression in tomato seedlings was promoted after 12 h of treatment under different NaCl concentrations. The amount of Le-EIL2 transcript increased after 12 and 24 h in 0.08 mol/l NaCl, and the same effect was observed for Le-EIL3 gene expression in tomato seedlings grown in 0.04 and 0.08 mol/l NaCl. After 12 h, Le-ERF1 gene expression was significantly enhanced by 0.04 and 0.08 mol/l NaCl treatments. Le-ERF2 gene transcriptional expression increased with the application of 0.04, 0.08 and 0.16 mol/l NaCl to seedlings. However, Pti4 gene expression did not change remarkably. These results suggest that different temporal gene expression patterns exist in Le-EIL and Le-ERF family members after NaCl stress induction.
