Differential Expression of The Tasos4 Gene in Salt-Tolerant and Salt-Sensitive Wheat (Triticum aestivum L.) Varieties

Abstract

Salinity is a major abiotic stress that significantly impacts crop growth, yield, and quality, particularly in arid and semi-arid regions. The Salt Overly Sensitive (SOS) gene family plays a critical role in plant responses to salt stress by maintaining ion homeostasis. Among these, the TaSOS4 gene, associated with pyridoxal kinase activity, is believed to contribute to salt tolerance by regulating cellular metabolism and ion transport. In this study, we analyzed the differential expression of the TaSOS4 gene in two bread wheat (Triticum aestivum L.) varieties: the salt-tolerant 'E'zoz' and the salt-sensitive 'Faw-43'. Ten-day-old seedlings were subjected to 100 mM and 200 mM NaCl treatments for 48 hours, and quantitative real-time PCR (qRT-PCR) was used to evaluate gene expression levels. Our results revealed that the TaSOS4 gene is highly expressed in the salt-tolerant 'E'zoz' variety under increasing salt concentrations, indicating its potential role in enhancing salt tolerance. In contrast, the salt-sensitive 'Faw-43' exhibited minimal expression of TaSOS4 under both control and stress conditions. These findings suggest that the activation of TaSOS4 contributes to maintaining ion balance and protecting cellular integrity under saline environments. The consistent expression of the reference Actin gene confirmed the reliability of our qRT-PCR data. This study highlights the importance of TaSOS4 as a genetic resource for improving salt tolerance in wheat. The differential expression patterns observed between tolerant and sensitive varieties underscore its potential for breeding programs aimed at developing resilient wheat cultivars. Further research into the regulatory mechanisms of TaSOS4 could provide deeper insights into its role in plant stress responses and its application in sustainable agriculture.