آنالیز مقایس هایی متابولی تها به منظور شناسایی ژنوتیپهای با کارایی انتقال مجدد بالا در مرحله پرشدن دانه جو در پاسخ به تنش خشک ی

Objective: Drought conditions at the terminal of grain filling stage are one of the main factors limiting barley yield. In stressful conditions, due to the limitation of current photosynthesis, the importance of storing more stems and its contribution to the production of the final product will be significant. Among other internodes of the stem, the penultimate internode plays the most important role in remobilization. The aim of this study is to investigate the drought tolerance of two cultivars and one line of barley with different degrees of remobilize of substances and also to investigate the comparative metabolic analysis on the penultimate internodes of three genotypes of barley Yousef (tolerant), Morocco (sensitive) and line PBYT17 (semi-tolerant) under the terminal of grain filling stage. 

Materials and methods: Evaluation of metabolomics analysis of barley genotypes (Yousef, Morocco and line PBYT17) in response to drought stress was carried out 21 and 28 days after the application of drought stress in the grain filling stage. Also, the ability to remobilize stem penultimates of Yusuf, Morocco and PBYT17 genotypes in response to drought was investigated. Identification of metabolites profile which included 17 metabolites including soluble sugars, sugar phosphate, sugar nucleotide, organic acids, phosphorylated metabolites and nucleotides. 

Results: The results obtained from the metabolomics data showed that Youssef cultivar had a significantly higher efficiency than other cultivars in retransmission, related to penultimate. Among the investigated genotypes, 17 metabolites were identified. The amount of transferred reserves and the amount of remobilization efficiency were significantly different among different genotypes. Two cultivars Yousef and Morocco had the highest and lowest remobilization efficiency under stress conditions, respectively. Our results showed that the tolerant genotype, by increasing UDP-glucose and glucose-6-phosphate, led to the synthesis of trehalose-6-phosphate, which plays a key role in remobilization materials in the stem. 

Conclusions: In general, the results of this research show that the effective metabolites in the remobilze of stem reserves can play a major role in maintaining the performance of barley plants during the drought stress at the end of the season, and this issue can be targeted solutions to increase the genotype performance. The desired varieties of barley that face drought stress at the end of the season should be used. This study may provide potential directions and valuable resources for further study of drought stress in the barley.