Plant breeding for abiotic & biotic stresses
Morteza Barati; mohammad reza azimi; Mohammad Reza Naghavi; Ehsan Mohsenifard
Abstract
MicroRNAs (miRNAs) are small RNAs of about 22 nucleotides. They are commonly known for their essential roles in regulating biotic and abiotic stress response in plants. Drought stress is one of the most common problems for wheat (Triticum aestivum L.) productivity in Iran. The present study evaluated ...
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MicroRNAs (miRNAs) are small RNAs of about 22 nucleotides. They are commonly known for their essential roles in regulating biotic and abiotic stress response in plants. Drought stress is one of the most common problems for wheat (Triticum aestivum L.) productivity in Iran. The present study evaluated the expression of miR9863a and its drought-related target genes (PLGG1 and SAR1A) in wheat and three Aegilops species under drought stress. Drought stress was induced by limiting the irrigation, maintaining the soil moisture at 20% field capacity for 14 days, followed by 3 days without water supply. The results showed the differently expression of miR9863a in the shoot of the studied plants under drought stress condition, so that its expression was increased in Ae. tauschii and Ae. crassa and decreased in Ae. cylindrica. This difference expression could be due to the mixing of RNAs of different tissues of shoots or the nature of miRNA as a mediator molecule in various biological processes. By considering the expression pattern of miR9863a and its target genes in Ae. tauschii, it could be attributed to the effect of miR9863a in response to drought stress by PLGG1 through its role in glycerate/glycolate transfers and SAR1A through the role of trafficking of transcription factors from the endoplasmic reticulum to the nucleus. Also, as a complement to previous studies on the role of miR9863 in countering plant diseases, the results herein demonstrated how this miRNA assists the abiotic stress-response mechanism in plants, with an emphasis on drought stress.
Plant molecular physiology & breeding
Mostafa Zibanezhadian; Babak Pakdaman Sardrood; Hengameh Taheri; Mohammad Farkhari
Abstract
Under global warmth conditions, it is expected that tomato yield will reduce due to insect pests and fungal diseases such as fusarium wilt. Using of biological control agents is effective in the control of both groups as regard as an ecofriendly and economically rational practice. Here, Bacillus thuringiensis ...
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Under global warmth conditions, it is expected that tomato yield will reduce due to insect pests and fungal diseases such as fusarium wilt. Using of biological control agents is effective in the control of both groups as regard as an ecofriendly and economically rational practice. Here, Bacillus thuringiensis (Bt) was used to study its capability to prime tomato resistance against fusarium wilt caused by the fungus Fusarium oxysporum f. sp. lycopersici (Fol). Priming of tomato cv. Falat C.H. seedlings was performed at 4-5 leaf stage and leaf samples were analyzed 3, 18, 24, 48 and 72 hours after fungal treatment (hat). The rate of hydrogen peroxide (H2O2) and changes in the relative transcription of the antioxidant enzyme genes such as superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) were evaluated using qRT-PCR. No significant change was observed in the relative transcription of the CAT gene. The relative transcription of SOD, and GST genes was increased with time in the treated plants compared to control plants. The highest rate of relative transcription of SOD was found at 18 and 24 hat, and for GST at 18 and 72 hat. The increment of genes transcripts was in agreement with the reduced level of H2O2 in Bt-primed plants. These results are in accordance with the effectiveness of Bt in the induction of tomato systemic resistance to the F. oxysporum f. sp. lycopersici.
Molecular biology and (trans) gene expression technology in plant breeding
Arezoo Pourfarid; Ali Pakdin-Parizi; Reza Ghorbani-Nasrabad; Heshmatollah Rahimian
Abstract
Arbuscular mycorrhizal fungi (AMF) symbiosis could mitigate the adverse effects of abiotic stresses in various plants. The aim of this study was to investigate the effect of AMF-inoculation on expression of several stress-responsive genes in two rice cultivars under different water conditions. The seedlings ...
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Arbuscular mycorrhizal fungi (AMF) symbiosis could mitigate the adverse effects of abiotic stresses in various plants. The aim of this study was to investigate the effect of AMF-inoculation on expression of several stress-responsive genes in two rice cultivars under different water conditions. The seedlings of Tarom-Hashemi and Nemat rice cultivars were transplanted in soil with or without G. mosseae spores. At the tilling stage, the AMF-inoculated (+AMF) and AMF-uninoculated (−AMF) plants were subjected to flooded and water deficit conditions (70% field capacity (FC) and 50%FC). The genes expression was evaluated by qRT-PCR and reported relative to control (flooded, -AMF) plants. The results showed lower expression of osDREB2A in +AMF plants in comparison with –AMF plants under water deficient conditions. The expression of OsPIP1;2 was significantly increased in roots of +AMF to –AMF plants. But, the expression of this gene was decreased in shoots of +AMF and –AMF plants in comparison with control plants. The stress-responsive gene transcripts, OsPIP2;3, OsGH3-8, OsLTP, OsAOS2 and OsADC1 in +AMF rice cultivars was higher than -AMF plants at both water deficit conditions. Expression of OsP5CS in +AMF and –AMF plants was increased in comparison with control plants, though, their differences was not significant. In 70%FC, OsEXP15 gene expression of +AMF and –AMF root plants was increased in comparison with control plants. However, under 50%FC the gene expression was decreased and not changed in -AMF and +AMF plants, respectively. It seems AMF induced changes in rice genes expression may enhance tolerance to water deficit conditions.
Erfan Jamshidi; Maryam Parvini Kohneh shahri; Reza Darvishzadeh
Abstract
Sclerotinia stem rot disease caused by Sclerotinia sclerotiorum is one of the most important diseases of sunflower. Telomeres are nucleoprotein structures at the ends of chromosomes that are essential for maintaining the integrity of the genome. The aim of this study was to determine the alteration of ...
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Sclerotinia stem rot disease caused by Sclerotinia sclerotiorum is one of the most important diseases of sunflower. Telomeres are nucleoprotein structures at the ends of chromosomes that are essential for maintaining the integrity of the genome. The aim of this study was to determine the alteration of telomerase enzyme gene (tert) expression under fungal infection stress. The expression of tert gene in both susceptible (SDR19) and resistant (LC1064-C) genotypes of sunflower was evaluated by qRT-PCR after infection with A37 isolate of S. sclerotiorum. The results showed significant and drastic decreased levels of tert expression in both susceptible and resistant genotypes of sunflower, immediately after fungal infection. This depletion followed by mild variation when infection continued for more hours, which was more constant in resistant line, compared with the susceptible one. In conclusion, the expression of tertgene in sunflower is downregulated in response to Sclerotinia rot disease.