*3.3. C. songorica Gene Promoter and Gene Expression Analysis*

ABA and stress responsive *cis*-regulatory elements, such as ABRE, MBS/MYB and G-Box were found to be abundant in the promoters of *C. songorica* Dehydrin and the *LEA\_2* subfamilies genes. These regulatory elements are known to provide binding sites for transcription factors like ABEF (a member of the bZIPTFs family), BHLH and ERF for the transcription of downstream stress responsive genes [46]. Expression analysis of *CsLEA37* and *CsLEA38* (*DEHYDRIN* genes), and *CsLEA14* and *CsLEA19* (*LEA\_2* subfamily genes) with qRT-PCR indicated that the expression levels of these four genes in root and shoot tissues were significantly up-regulated after the drought or ABA treatment.

The relevant role of DEHYDRIN or the LEA\_2 subfamily proteins during plant stress tolerance has been reported in earlier studies using various transgenic plants. For example, transgenic tobacco plant overexpressing the *CaLEA6* gene showed an enhanced dehydration and salt tolerance [47]. Additionally, sweet potato plants overexpressing the *IbLEA14* gene exhibited an improved salinity and dehydration tolerance [48]. A Foxtail millet plant overexpressing the *SiLEA4* gene displayed salt and drought resilience [49]. For DEHYDRIN proteins, transgenic Arabidopsis plant expressing a *Dehydrin* gene from an olive showed an enhanced osmotic stress tolerance [50]. Similarly, a wheat *Dhn-5* gene increased salinity and dehydration stress tolerance in transgenic Arabidopsis plants [51]. *C. songorica DEHYDRIN* and *LEA\_2* gene transcripts accumulation during water deficit and ABA treatment, reinforcestheir functional importance under detrimental stress conditions.
