نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه ایلام، ایلام، ایران.
2 موسسه تحقیقات کشاورزی دیم، معاونت سرارود، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرمانشاه، ایران.
3 گروه بیوتکنولوژی و بهنژادی گیاهی، واحد کرمانشاه، دانشگاه آزاد اسلامی، کرمانشاه، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction: Drought stress is one of the most important factors limiting the productivity of durum wheat (Triticum durum L.) in arid and semi-arid regions of the world, and understanding the response of genes at the molecular level is essential for the development of tolerant cultivars. Therefore, the present study aimed to investigate the relative expression of six key genes related to drought response, including TdDhn5 and Wdhn13 (dehydrin genes), TdAPX1 and TdCAT1 (antioxidant genes), and TdDRF1 and TdDREB1 (transcription factors), in seven durum wheat genotypes including (Zahab, G6, G8 and G9 as sensitive and genotypes G10, G12 and G14 as tolerant under no stress, mild, and severe conditions. The primary objective of the study was to identify genotype-based expression patterns and assess their potential as factors for enhancing drought tolerance.
Materials and methods: Wheat seeds were grown in greenhouse conditions in pots with a volume of approximately 2 liters containing 1.5 kg of field soil. Drought stress was applied at the three-leaf stage at two levels: mild and severe. Mild drought with biweekly irrigation and severe drought stress at the 3-leaf stage with complete cutting. Irrigation was induced according to the method described by Moradi et al. (2024). Each irrigation was 250 cc. After four weeks of exposure to stress, sampling was performed. The third fully opened leaf was harvested from three biological replicates of the pot for each genotype in each treatment, with each replicate consisting of five plants. Total RNA was extracted from the third leaves of the seedlings at the 3-4 leaf stage by the TRIzol method and after cDNA synthesis, gene expression was quantified by the technique using the Actin gene as a reference gene. Data were analyzed using ANOVA and the LSD test (p < 0.05).
Results: The results showed that the expression of the dehydrin genes TdDhn5 and TdWdhn13 increased significantly under mild and severe stress conditions (50% and 100%, respectively). In severe stress, the highest expression value was observed in the G14 genotype for TdDhn5 and in the G12 genotype for TdWdhn13. Antioxidant genes TdAPX1 and TdCAT1 were also upregulated under both mild and severe stress conditions, with the increase being greater in drought-tolerant genotypes. Notably, under severe stress, TdAPX1 expression was prominent in Genotype G9, and TdCAT1 expression was observed in genotype G12. Transcription factors TdDRF1 and TdDREB1 demonstrated their regulatory role, with increased expression under mild stress and a peak under severe stress, particularly in Genotypes G12 and G14.
Conclusion: This study clarified gene- and genotype-specific expression patterns in response to drought stress and identified G12 genotype as a prominent candidate for tolerance. The coordinated increase in dehydrin genes and transcription factors in response to severe stress confirms their potential as molecular markers in durum wheat breeding programs for drought tolerance. The need for field studies to validate these findings is recommended.
کلیدواژهها [English]
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