scholarly journals Overexpression of the pitaya phosphoethanolamine N-methyltransferase gene (HpPEAMT) enhanced simulated drought stress in tobacco

Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.

2021 ◽  
Author(s):  
Alireza Abbasi ◽  
Meysam Malekpour ◽  
Sajjad Sobhanverdi

Abstract Expansins are cell wall proteins that, due to changes in pH, causing the expansion of the cell walls. In this study, a previously gene construct designed based on a root-specific gene, AtEXPA18, was utilized to assess its potential roles on different morphological, physiological, and cellular levels of generated transgenic tobacco plants in response to moderate and severe drought stress. AtEXPA18 gene was successfully transferred to the tobacco plants through an agrobacterium-mediate transformation system. Upon obtaining the second generation, tobacco transgenic plants were confirmed by conventional polymerase chain reaction (PCR) technique alongside reverse transcription PCR (RT-PCR) using specific primers. Under drought stress, the transgenic lines showed remarkable growth and significantly improved based on morphological traits such as height and stem diameter, leaf area, leaf number, root dry weight, and Abscisic acid (ABA) levels of leaves compared control plants. As a result, the Cytokinin content of transgenic plants has increased under severe stress levels. Notably, the area's expansion for abaxial epidermal cells under the microscope confirmed in transgene cells compared with the -transgene cells. These results, altogether, could support the AtEXPA18 gene implication in cell expansion and improving tolerance capacity of transgenic crops under drought stress.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Liu ◽  
Xinzhuan Yao ◽  
Lu Zhang ◽  
Litang Lu ◽  
Renxiang Liu

Drought is the primary disaster that endangers agricultural production, including animal husbandry, and affects the distribution, growth, yield, and quality of crops. Previous study had revealed that DIP, as a potential regulator of DBF activity, played an important role in response to drought stress in maize. In this study, a total of 67 DIPs were identified from seventeen land plants, including six tobacco DIPs (NtDIPs). NtDIP6 gene was further selected as a candidate gene for subsequent experiments based on the phylogenetic analysis and structural analysis. The transgenic tobacco and poplar plants over-expressing NtDIP6 gene were generated using the Agrobacterium- mediated method. Although there was not phenotypic difference between transgenic plants and wild-type plants under normal conditions, overexpression of the NtDIP6 gene in transgenic tobacco and poplar plants enhanced the drought tolerance under drought treatments in comparison with the wild type. The content of antioxidant defense enzymes peroxidase (POD), catalase (CAT), and the photosynthetic rate increased in NtDIP6-Ox transgenic tobacco and poplar plants, while the content of malondialdehyde decreased, suggesting that the overexpression of NtDIP6 enhances the antioxidant capacity of transgenic poplar. Furthermore, the results of qRT-PCR showed that the level of expression of drought-related response genes significantly increased in the NtDIP6-Ox transgenic plants. These results indicated that NtDIP6, as a positive response regulator, improves drought stress tolerance by scavenging superoxide via the accumulation of antioxidant defense enzymes.


Author(s):  
Ben Hu ◽  
Heng Yao ◽  
Xiaojun Peng ◽  
Ran Wang ◽  
Feng Li ◽  
...  

Flavonoids are major secondary metabolites in plants, which play important roles in maintaining the cellular redox balance in cells. Chalcone synthase (CHS) is the key enzyme in the flavonoids biosynthesis pathway, and has been proved to monitor the changes to drought stress tolerance. In this work, we overexpressed a CHS gene in tobacco (Nicotiana tabacum). The transgenic tobacco plants were more tolerant than the control plants to drought stress. The transcription levels of the key genes involved in the flavonoids pathway and the contents of seven flavonoids were also significantly raised in the transgenic tobacco plants. In addition, overexpression of the CHS gene lead to a lower concentration of the oxidative stress product malondialdehyde. Overall, the NtCHS gene studied in this work was considered as a candidate gene for genetic engineering to enhance drought tolerance of plants and improve response to oxidative stress.


2020 ◽  
Author(s):  
Ben Hu ◽  
Heng Yao ◽  
Yulong Gao ◽  
Ran Wang ◽  
Feng Li ◽  
...  

Abstract Flavonoids are important secondary metabolites in plants that play important roles in maintaining the cellular redox balance of cells. Chalcone synthase (CHS) is the key enzyme in the flavonoid biosynthesis pathway and has been found to monitor changes due to drought stress tolerance. In this study, a CHS gene in tobacco ( Nicotiana tabacum ) was overexpressed. Results revealed that transgenic tobacco plants were more tolerant than control plants to drought stress. Transcription levels of the key genes involved in the flavonoid pathway and the contents of seven flavonoids significantly increased in transgenic tobacco plants ( p < 0.01). Overexpression of the CHS gene led to lower concentrations of the oxidative stress product, malondialdehyde (MDA). Additionally, 11 CHS family genes were mined from the tobacco genome. Based on the phylogenetic tree, these genes split into two groups with eight genes clustered together with the bona fide Arabidopsis CHS gene, suggesting that those tobacco genes are CHS genes. Further phylogenetic analyses indicated that the tobacco CHS genes grouped further into three independent clades with the cloned tobacco CHS gene located within Clade iii. The tobacco CHS family genes exhibited a highly conserved CDS length, pI, and molecular weight of the encoded peptides. All CHS peptides contained two conserved domains, and the genes harbored two or three exons. Based on the results of this study, the NtCHS gene is considered a possible candidate gene for genetically engineering enhanced drought tolerance and improved responses to oxidative stress in plants.


Author(s):  
Ben Hu ◽  
Heng Yao ◽  
Yulong Gao ◽  
Ran Wang ◽  
Feng Li ◽  
...  

Abstract Background: Flavonoids are important secondary metabolites in plants that play important roles in maintaining the cellular redox balance of cells. Chalcone synthase (CHS) is the key enzyme in the flavonoid biosynthesis pathway and has been found to monitor changes due to drought stress tolerance.Results: In this study, a CHS gene in tobacco (Nicotiana tabacum) was overexpressed. Results revealed that transgenic tobacco plants were more tolerant than control plants to drought stress. Transcription levels of the key genes involved in the flavonoid pathway and the contents of seven flavonoids significantly increased in transgenic tobacco plants (p < 0.01). Overexpression of the CHS gene led to lower concentrations of the oxidative stress product, malondialdehyde (MDA). Additionally, 11 CHS family genes were mined from the tobacco genome. Based on the phylogenetic tree, these genes split into two groups with eight genes clustered together with the bona fide Arabidopsis CHS gene, suggesting that those tobacco genes are CHS genes. Further phylogenetic analyses indicated that the tobacco CHS genes grouped further into three independent clades with the cloned tobacco CHS gene located within Clade iii. The tobacco CHS family genes exhibited a highly conserved CDS length, pI, and molecular weight of the encoded peptides. All CHS peptides contained two conserved domains, and the genes harbored two or three exons.Conclusions: Based on the results of this study, the NtCHS gene is considered a possible candidate gene for genetically engineering enhanced drought tolerance and improved responses to oxidative stress in plants.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1749
Author(s):  
Samuel Aduse Poku ◽  
Peter Nkachukwu Chukwurah ◽  
Htut Htet Aung ◽  
Ikuo Nakamura

Climate change, with its attendant negative effects, is expected to hamper agricultural production in the coming years. To counteract these negative effects, breeding of environmentally resilient plants via conventional means and genetic engineering is necessary. Stress defense genes are valuable tools by which this can be achieved. Here we report the successful cloning and functional characterization of a melon Y3SK2-type dehydrin gene, designated as CmLEA-S. We generated CmLEA-S overexpressing transgenic tobacco lines and performed in vitro and in vivo drought and salt stress analyses. Seeds of transgenic tobacco plants grown on 10% polyethylene glycol (PEG) showed significantly higher germination rates relative to wild-type seeds. In the same way, transgenic seeds grown on 150 mM sodium chloride (NaCl) recorded significantly higher germination percentages compared with wild-type plants. The fresh weights and root lengths of young transgenic plants subjected to drought stress were significantly higher than that of wild-type plants. Similarly, the fresh weights and root lengths of transgenic seedlings subjected to salt stress treatments were also significantly higher than wild-type plants. Moreover, transgenic plants subjected to drought and salt stresses in vivo showed fewer signs of wilting and chlorosis, respectively. Biochemical assays revealed that transgenic plants accumulated more proline and less malondialdehyde (MDA) compared with wild-type plants under both drought and salt stress conditions. Finally, the enzymatic activities of ascorbate peroxidase (APX) and catalase (CAT) were enhanced in drought- and salt-stressed transgenic lines. These results suggest that the CmLEA-S gene could be used as a potential candidate gene for crop improvement.


2021 ◽  
Vol 5 (1) ◽  
pp. 168-182
Author(s):  
Hatice DAGHAN ◽  
Veli UYGUR ◽  
Abdullah EREN

Genetiği değiştirilmiş bitkiler, kurşunun (Pb) kökten yer üstü kısımlarına translokasyonunu geliştirmek için büyük bir potansiyele sahip olabilir. Transgenik olmayan ( Nicotiana tabacum L. cv. Petit Havana SR1) ve transgenik (p-cV-ChMTII GFP) tütün bitkileri tarafından Pb alımının sağlanması araştırmak için Çin hamsteri metalotiyonin II gezen bir kap deneyi yapıldı . Transgenik ve transgenik olmayan tütün bitkileri, 0, 1000, 2500, 5000 mg Pb kg- 1 ile Pb (NO 3 ) 2 olarak işlenmiş topraklarda yetiştirildi. Kelimede bir büyüme bölümünde 6 hafta boyunca çiçeklenme aşamasına kadar.Bitkilerin büyümesi, klorofil içeriği, mineral besin elementleri ve düşük glutatyon (GSH) bezleri, bitkilerin Pb alım potansiyeli ile birlikte incelenmiştir. Hem transgenik hem de transgenik olmayan bitkiler için Pb uygulamasındaki artışa bağlı olarak yer üstü biyokütle çevrildi aşamalı bir düşüş gözlendi. Yaprak besinlerinin bulaştığı, aşırı Pb işlemlerinden olumsuz etkilenmiştir, bunlardan en büyük düşüşü. Sürgün Pb yüksek derecesi 76.0 mg kg kadar ulaşan -1 transgenik ve 70.9 mg kg -1 transgenik olmayan bitkilerde. Pb alımı, p-cV-ChMTII GFP'nin tütün bitkisine aktarılmasıyla iyileştirildi; ancak, Pb fitoremediasyonunda yeterli değildi. 


2004 ◽  
Vol 84 (3) ◽  
pp. 785-790 ◽  
Author(s):  
Jianhong Yao, Xiuyun Zhao ◽  
Huaxiong Qi, Bingliang Wan ◽  
Fei Chen, Xiaofen Sun ◽  
Shanqian Yu ◽  
Kexuan Tang

Tobacco leaf discs were transformed with a plasmid, pBIAHA, containing the selectable marker neomycin phosphotransferase gene (nptII) and an Arisaema heterophyllum agglutinin gene (aha) via Agrobacterium tumefaciens-mediated transformation. Thirty-two independent transgenic tobacco plants were regenerated. PCR and Southern blot analyses confirmed that multiple copies of the aha gene had integrated into the plant genome. Northern blot analysis revealed that the aha gene was expressed at various levels in the transgenic plants. Insect bioassay test showed that transgenic plants expressing multiple copies of the aha gene reduced the rate of population increase of the peach potato aphid (Myzus persicae Sulzer). This is the first report that transgenic tobacco plants expressing the aha gene display enhanced resistance to aphids. Key words: Insect bioassay, Arisaema heterophyllum agglutinin, transformation, transgenic tobacco, peach potato aphid (Myzus persicae Sulzer)


Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 806
Author(s):  
Eun Jin Cho ◽  
Quynh Anh Nguyen ◽  
Yoon Gyo Lee ◽  
Younho Song ◽  
Bok Jae Park ◽  
...  

Here, we report an increase in biomass yield and saccharification in transgenic tobacco plants (Nicotiana tabacum L.) overexpressing thermostable β-glucosidase from Thermotoga maritima, BglB, targeted to the chloroplasts and vacuoles. The transgenic tobacco plants showed phenotypic characteristics that were significantly different from those of the wild-type plants. The biomass yield and life cycle (from germination to flowering and harvest) of the transgenic tobacco plants overexpressing BglB were 52% higher and 36% shorter than those of the wild-type tobacco plants, respectively, indicating a change in the genome transcription levels in the transgenic tobacco plants. Saccharification in biomass samples from the transgenic tobacco plants was 92% higher than that in biomass samples from the wild-type tobacco plants. The transgenic tobacco plants required a total investment (US$/year) corresponding to 52.9% of that required for the wild-type tobacco plants, but the total biomass yield (kg/year) of the transgenic tobacco plants was 43% higher than that of the wild-type tobacco plants. This approach could be applied to other plants to increase biomass yields and overproduce β-glucosidase for lignocellulose conversion.


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