Functional characterization of tobacco (Nicotiana benthamiana) serotonin N-acetyltransferases (NbSNAT1 and NbSNAT2)

2021 ◽  
Vol 4 (4) ◽  
pp. 507-521
Author(s):  
Kyoungwhan Back ◽  
Lee Hyoung Yool ◽  
Hwang Ok Jin
Keyword(s):  
Transgenic Tobacco ◽  
Nicotiana Benthamiana ◽  
Feedback Inhibition ◽  
Functional Characterization ◽  
Substrate Affinity ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants ◽  
Maximum Reaction Rate ◽  
Maximum Reaction

Nicotiana benthamiana (tobacco) is an important dicotyledonous model plant; however, no serotonin N-acetyltransferases (SNATs) have been characterized in tobacco. In this study, we identified, cloned, and characterized the enzyme kinetics of two SNAT genes from N. benthamiana, NbSNAT1 and NbSNAT2. The substrate affinity (Km) and maximum reaction rate (Vmax) for NbSNAT1 were 579 µM and 136 pkat/mg protein for serotonin, and 945 µM and 298 pkat/mg protein for 5-methoxytryptamine, respectively. Similarly, the Km and Vmax values for NbSNAT2 were 326 µM and 26 pkat/mg protein for serotonin, and 872 µM and 92 pkat/mg protein for 5-methoxytryptamine, respectively. Moreover, we found that NbSNAT1 and NbSNAT2 localized to chloroplasts, similar to SNAT proteins from other plant species. The activities of the NbSNAT proteins were not affected by melatonin feedback inhibition in vitro. Finally, transgenic tobacco plants overexpressing either NbSNAT1 or NbSNAT2 did not exhibit increased melatonin levels, possibly due to the expression of catabolic enzymes. Generating transgenic tobacco plants with downregulated NbSNAT expression would provide further insight into the functional role of melatonin in tobacco plants. 

Functional characterization of chrysanthemum SEPALLATA3 homologs CDM77 and CDM44 in transgenic tobacco plants

2012 ◽  
Vol 443 (1) ◽  
pp. 87-90 ◽  
Author(s):  
E. N. Goloveshkina ◽  
O. A. Shulga ◽  
A. V. Shchennikova ◽  
A. M. Kamionskaya ◽  
K. G. Skryabin
Keyword(s):  
Transgenic Tobacco ◽  
Functional Characterization ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants

scholarly journals Production of transgenic tobacco plants expressing GS1 gene for the increase ofnitrogen use efficiency

2016 ◽  
Vol 14 (3) ◽  
pp. 507-513
Author(s):  
Nguyễn Thị Hồng Gấm ◽  
Trần Thị Hương Giang ◽  
Bùi Phương Thảo ◽  
Nguyễn Văn Đoài ◽  
Nguyễn Thị Thơm ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Transgenic Tobacco ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Scientific Basis ◽  
Transgenic Tobacco Plants ◽  
Tobacco Plants ◽  
Gm Plants ◽  
Use Efficiency

Glutamine synthetase (GS, CE 6.3.1.2) is an enzyme that catalyzes the ATP-dependent condensation of glutamic acid with ammonia to yield glutamine. Glutamine synthetase is a key enzyme involved in the assimilation of inorganic nitrogen into organic forms. In plant cells, GS is present in both chloroplasts (GS2) and cytoplasm (GS1), in which GS1 can assimilate nitrogen source. In this study, one transgenic vector pBI121 carrying GS1 gene under the control of promoter 35S (pBI121::GS1) were successfully constructed. This vector containing G1S gene was transformed into tobacco leaves pieces via Agrobacterium tumefaciens strain C58. Five weeks after cultivation, there were 28 tobacco lines which had roots on the medium added kanamycin 50 mg/l. Then, the presence of G1S gene in these tobacco lines was tested from leaves in the next experiments. PCR and Southern blot confirmed that there are five tobacco lines carrying transferred GS1 gene. The effectiveness of nitrogen using in GS1 transgenic tobacco plants in vitro was evaluated. The tissue fresh weight, number and height of shoots forming buds and rooting ability of GS1 transgenic tobacco plants were greater than those of non-GM plants in the medium of low nitrogen concentration (0.1X - 0.2X). Assessment of crop growing in a greenhouse demonstrated that GS1 transgenic tobacco plants grow faster than non-transgenic ones. In detail, the increment of plant height after planting 03 months and 05 months in greenhouse is 43.55% and 33.29%, respectively. These results provide a scientific basis for the development of other genetically modified plants which enhanced nitrogen-use efficiency.

Production of an active recombinant thrombomodulin derivative in transgenic tobacco plants and suspension cells

2005 ◽  
Vol 14 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Helga Schinkel ◽  
Andreas Schiermeyer ◽  
Raphael Soeur ◽  
Rainer Fischer ◽  
Stefan Schillberg
Keyword(s):  
Transgenic Tobacco ◽  
Transgenic Tobacco Plants ◽  
Suspension Cells ◽  
Tobacco Plants ◽  
Recombinant Thrombomodulin

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

2021 ◽  
Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Transgenic Plants ◽  
Drought Tolerance ◽  
Transgenic Tobacco ◽  
Sequence Similarity ◽  
Amino Acid Sequence Similarity ◽  
Transgenic Tobacco Plants ◽  
Wild Type ◽  
Tobacco Plants

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.

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