RNA-Seq analysis revealed genes associated with drought stress response in kabuli chickpea (Cicer arietinum L.)

Drought is the most important constraint that effects chickpea production globally. RNA-Seq has great potential to dissect the molecular mechanisms of tolerance to environmental stresses. Transcriptome profiles in roots and shoots of two contrasting Iranian kabuli chickpea genotypes (Bivanij and Hashem) were investigated under water-limited conditions at early flowering stage using RNA-Seq approach. A total of 4,572 differentially expressed genes (DEGs) were identified. Of these, 261 and 169 drought stress responsive genes were identified in the shoots and the roots, respectively, and 17 genes were common in the shoots and the roots. Gene Ontology (GO) analysis revealed several sub-categories related to the stress, including response to stress, defense response and response to stimulus in the tolerant genotype Bivanij as compared to the sensitive genotype Hashem under drought stress. In addition, several Transcription factors (TFs) were identified in major metabolic pathways such as, ABA, proline and flavonoid biosynthesis. Furthermore, a number of the DEGs were observed in "QTL-hotspot" regions which were reported earlier in chickpea. Drought tolerance dissection in the genotypes revealed that the genes and the pathways involved in shoots of Bivanij were the most important factor to make a difference between the genotypes for drought tolerance. The identified TFs in the experiment, particularly those which were up-regulated in shoots of Bivanij during drought stress, were potential candidates for enhancing tolerance to drought

RNA-Seq analysis revealed genes associated with drought stress response in kabuli chickpea (Cicer arietinum L.)

Drought is the most important constraint that effects chickpea production globally. RNA-Seq has great potential to dissect the molecular mechanisms of tolerance to environmental stresses. Transcriptome profiles in roots and shoots of two contrasting Iranian kabuli chickpea genotypes (Bivanij and Hashem) were investigated under water-limited conditions at early flowering stage using RNA-Seq approach. A total of 4,572 differentially expressed genes (DEGs) were identified. Of these, 261 and 169 drought stress responsive genes were identified in the shoots and the roots, respectively, and 17 genes were common in the shoots and the roots. Gene Ontology (GO) analysis revealed several sub-categories related to the stress, including response to stress, defense response and response to stimulus in the tolerant genotype Bivanij as compared to the sensitive genotype Hashem under drought stress. In addition, several Transcription factors (TFs) were identified in major metabolic pathways such as, ABA, proline and flavonoid biosynthesis. Furthermore, a number of the DEGs were observed in “QTL-hotspot” regions which were reported earlier in chickpea. Drought tolerance dissection in the genotypes revealed that the genes and the pathways involved in shoots of Bivanij were the most important factor to make a difference between the genotypes for drought tolerance. The identified TFs in the experiment, particularly those which were up-regulated in shoots of Bivanij during drought stress, were potential candidates for enhancing tolerance to drought

Transcription factors evaluation in a transcriptome analysis on Chickpea (Cicer arietinum L.) under drought stress

Drought causes detrimental effect on growth and productivity of many plants, including crops. Chickpea (Cicer arietinum L.) as one of the most important legume crops is subjected to terminal drought stress in arid and semi-arid regions. Transcription factors (TFs) play key roles during signal transduction and adaptation response to abiotic stresses such as drought. In the present study, TFs were assessed in a transcriptome analysis in the root and the shoot tissues of two contrasting drought responsive kabuli chickpea. Out of 4572 differentially expressed genes, 1806 TFs were identified using search on the plant transcription factor database (PTFD). The highest members (101) of the TFs belonged to bHLH family, followed by ERF (87), kinase superfamily (76), NAC (74), MYB (72), WRKY (72), etc. The comparison of the tolerant (Bivanij) and the sensitive (Hashem) cultivars under drought stress showed that the TFs were differently distributed based on the cultivars and the tissue types. The TF families including B3, NAC, MYB, WRKY, bHLH, etc. had most members in response to the drought stress. Furthermore, the results revealed that several TFs which were involved in abiotic stress-related responses and major biosynthetic pathways such as ABA and proline biosynthesis were up-regulated in the shoot of Bivanij as compared to Hashem indicating the vital role of the shoot for inducing drought tolerance in the tolerant cultivar. As result, these findings help the researches to better understanding of signal transduction and stress-related regulating networks in chickpea and provide the transferring of key TFs and promoting drought tolerance by genetic engineering

Transcriptome analysis of Iranian local chickpea in response to drought stress

Chickpea (Cicer arietinum L.) is one of the most important legumes for human food and plays major roles in soil productivity. This crop is subjected to terminal drought in arid and semi-arid regions such as Iran. Identification of drought-induced genes is necessary not only for understanding molecular mechanisms of drought tolerance, but also is important to develop tolerant crops. In present study, transcriptome profiling of Iranian local kabuli chickpea (Bivanij cultivar) was investigated under drought stress at early flowering stage at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). Illumina HiSeq2500 was applied for sequencing the root and the shoot samples under control and stress conditions. A total of 891 and 507 differentially expressed genes (DEGs) were identified in response to the drought stress in the root and the shoot, respectively. Likewise, 760, 376 and 131 DEGs were detected specifically in the root, the shoot and common in both organs, respectively. Gene ontology (GO) analysis revealed several GO terms associated with stress, including response to stimulus and signaling among the DEGs in response to the drought stress. Moreover, major metabolic pathways such as ABA and proline biosynthesis, biosynthesis of secondary metabolites such as flavonoids and phenylpropanoids, carbohydrates and energy metabolisms were identified by KEGG pathway analysis. These findings showed that more drought-related genes and pathways were induced in the root compared to the shoot. Several DEGs particularly those which were functioned as transcription factors (TFs) related to drought responsive genes, can be used for future researches and improving drought tolerant cultivars

Effects of starvation and re-feeding on compensatory growth performance, plasma metabolites and IGF-I gene expression of Persian sturgeon (Acipenser persicus, Borodin 1897)

The effects of starvation and subsequent re-feeding on compensatory growth performance, blood serum metabolites and IGF-ImRNA expression in liver and muscle were investigated in juvenile Persian sturgeon. Growth indices including body weight, SGR, CF, and HSI significantly decreased after starvation. However, after re-feeding sturgeons that were starved for 1 week reached the same weight as the control, indicating that complete compensatory growth had occurred. Conversely, sturgeon in longer periods of starvation showed only partial growth compensation. HSI values decreased significantly during starvation, although they returned to the control fish levels after re-feeding. Plasma levels of glucose and insulin during starvation and re-feeding did not significantly change. This suggests that sturgeon is able to maintain glycaemia during starvation, probably due to their non-carbohydrates source dietary. Plasma total lipid level in un-fed treatments, however, was found to increase, possibly as a mechanism to utilise lipids as a fuel during starvation. IGF-I mRNA expression in liver and muscle increased during starvation and decreased after re-feeding. However, changes in the IGF-ImRNA expression were not significantly different among treatments. These results indicate that a periodic short-term starvation in Persian sturgeon does not adversely sacrifice overall fish weight gain and sturgeon can realise compensatory growth