Researchers need continuously improve their views on mechanisms of salt tolerancein crop plants in order to overcome their limitations and improve yields understress conditions including salt stress. One of the most important methods of controllingstresses in plants is through making adjustments during the process of genetranscription. Transcription factors adjust the degree of expression in many genesby binding to DNA and are thus very important in salt tolerance of plants. Therefore,the present research studied the role of transcription factors bHLH, CBF4, andZpt2-1in salt tolerance by investigating their expression patterns under salt stress inthe leaf and root tissues of the Yazdi (salt tolerant) and the Diabloverde (sensitiveto salinity) genotypes of Alfalfa. Results showed that short-term salt stress affectson expression patterns of the CBF4, Zpt2-1, and bHLH genes in leaf and root tissuesof both genotypes. Using qRT-PCR (Real-Time PCR) analysis, it was shownthat the transcription factors Zpt2-1 and CBF4 in the salt tolerant genotype (Yazdi)were expressed at a higher level in root tissues. In other words, it seems that higherexpression levels of the transcription factors Zpt2-1 and CBF4 were accompaniedby greater salt tolerance. This finding can help plant breeders to use these transcriptionfactors for selecting salt-tolerant genotypes in alfalfa.

With regard to its economic importance of grapevine, study on different aspects of factors that induce hardiness to the unexpected early-season and late-season cold seems to be essential. Some of the transcription factors are essential for synthesis of proteins that are important for cold adaptation. In the present study, differences in the expression patterns of two CBF1 and CBF4 transcription factors were evaluated under cold stress conditions in the “Khalili-Danedar”, “Shahroodi” and “Riparia”. Results showed that expression of CBF1 was increased at early minutes of cold stress and “Riparia” showed higher expression compared with two other genotypes. Also the least expression was recorded for “Shahroodi” after 24 h of cold treatment. Regarding CBF4, increase in the expression was started one hour after cold treatment and similar to the CBF1, the highest expression was recorded for “Riparia”. Results of expression patterns of these two genes in “Riparia” grape showed that expression of CBF4 was about 10 fold of CBF1.