Leila amraee - Biology Department, Faculty of Sciences, Urmia University, Urmia, Iran
Fatemeh Rahmani - Biology Department, Faculty of Sciences, Urmia University, Urmia, Iran,Institute of Biotechnology, Urmia University, Urmia, Iran
Babak Abdollahi Mandoulakani - Plant Breeding and Biotechnology Department, Agriculture Faculty, Urmia University, Urmia, Iran

Salinity is a common environmental stresses and a complex phenotypic and physiological phenomenon which limits worldwide agricultural crop yields. Transcriptional regulation of the stress-induced genes plays an important role in developing stress tolerance and responses. Brassinosteroids (BRs) are novel group of phytohormones which initiate adaptive reactions of plant cell metabolism against environmental stresse. The present investigation was carried out to study the effect of 24-epibrassinolide (24-epiBL) on expression patterns of ERF and MYB1-1 transcription factors in salt sensitive (TN-97-1) and tolerant (TN-97-106) flax cultivars under NaCl-stress. After surface sterilisation, seeds were soaked for 8h in distilled water (control) and in 10-8 M concentration of 24-epiBL. Then, twenty-one-day-old-plants were exposed to salt stress ( 0 and 150 mM ) for 21 days. Results showed that in sensitive cultivar, imposition of NaCl (150 mM) induced MYB1-1 and ERF mRNA level compared to control plants while two genes showed decrease in expression level in tolerant cultivar. On the other hand, the transcript level of two genes was elevated in 24-epiBL+NaCl treated TN-97-1 cultivar compared to NaCl treated plants whereas in 24-epiBL+NaCl treated TN-97-106 cultivar, ERF gene expression revealed decrease (26%) compared to NaCl treated plants and no significant difference was observed in MYB1-1 gene transcription level between 24-epiBL+NaCl treated and NaCl treated TN-97-106 cultivar. The results indicate different patterns of transcription expression in sensitive and tolerant cultivars in response to salinity and application of 24-epiBL under NaCl (150 mM) imposition.

24-epiBL, Transcription Factors, Flaxceed, Salinity