نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد، گروه بیوتکنولوژی، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران.
2 دانشیار، گروه بیوتکنولوژی، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران.
3 استادیار، پژوهشکده فناوری تولیدات گیاهی، پژوهشگاه افضلیپور، دانشگاه شهید باهنر کرمان، ایران.
4 استادیار، گروه بیوتکنولوژی، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران.
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Objective
Safflower (Carthamus tinctorius L.) is a drought-resistant and environmentally stress‑tolerant crop with considerable importance in the food, pharmaceutical, and industrial sectors due to its high content of unsaturated fatty acids, particularly linoleic acid. The ratio of unsaturated to saturated fatty acids plays an essential role in maintaining cell membrane fluidity and stability. Regulating the expression of key genes in their biosynthesis pathway, including FAD2 and SAD, can help elucidate the molecular mechanisms underlying salt stress tolerance.
Materials and Methods
To evaluate the molecular responses of safflower to salinity, two cultivars (Goldasht and American Line A) were subjected to salt treatments at concentrations of 100, 200, and 300 mM sodium chloride. RNA was extracted from leaf tissue, followed by cDNA synthesis. The expression levels of FAD2 and SAD were quantified using real-time PCR. Relative changes in gene expression were calculated using the 2^-ΔΔCt method. Statistical analyses were performed using REST software, and significance was assessed through the Pair-wise Fixed Reallocation Randomization Test.
Results
The results demonstrated that the Goldasht cultivar exhibited a coordinated gene expression pattern in response to increasing salinity. FAD2 expression increased from 1 to 3.65-fold, whereas SAD expression simultaneously decreased from 1 to 0.38-fold. These changes reflect an enhanced linoleic acid ratio, maintenance of membrane fluidity, and improved salt tolerance. In contrast, American Line A showed a biphasic response: FAD2 expression decreased after an initial rise at low salinity levels, and SAD expression increased up to 2.06-fold under high salinity. This pattern suggests a shift toward higher oleic acid content and altered membrane structure. Such responses primarily serve as survival and adaptation mechanisms under severe osmotic stress rather than improving oil quality.
Conclusion
The findings indicate that safflower genotypes employ different molecular strategies to cope with salinity. The selection or development of genotypes with stable FAD2 expression and proper SAD regulation can be an effective approach to enhancing salt tolerance and improving safflower oil quality under diverse environmental conditions.
کلیدواژهها [English]
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