scholarly journals Overexpression of an Agave Phosphoenolpyruvate Carboxylase Improves Plant Growth and Stress Tolerance

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 582
Author(s):  
Degao Liu ◽  
Rongbin Hu ◽  
Jin Zhang ◽  
Hao-Bo Guo ◽  
Hua Cheng ◽  
...  

It has been challenging to simultaneously improve photosynthesis and stress tolerance in plants. Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism that facilitates plant adaptation to water-limited environments. We hypothesized that the ectopic expression of a CAM-specific phosphoenolpyruvate carboxylase (PEPC), an enzyme that catalyzes primary CO2 fixation in CAM plants, would enhance both photosynthesis and abiotic stress tolerance. To test this hypothesis, we engineered a CAM-specific PEPC gene (named AaPEPC1) from Agave americana into tobacco. In comparison with wild-type and empty vector controls, transgenic tobacco plants constitutively expressing AaPEPC1 showed a higher photosynthetic rate and biomass production under normal conditions, along with significant carbon metabolism changes in malate accumulation, the carbon isotope ratio δ13C, and the expression of multiple orthologs of CAM-related genes. Furthermore, AaPEPC1 overexpression enhanced proline biosynthesis, and improved salt and drought tolerance in the transgenic plants. Under salt and drought stress conditions, the dry weight of transgenic tobacco plants overexpressing AaPEPC1 was increased by up to 81.8% and 37.2%, respectively, in comparison with wild-type plants. Our findings open a new door to the simultaneous improvement of photosynthesis and stress tolerance in plants.

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 859
Author(s):  
Nancy Sofia Hernández-Bueno ◽  
Ramón Suárez-Rodríguez ◽  
Edgar Balcázar-López ◽  
Jorge Luis Folch-Mallol ◽  
José Augusto Ramírez-Trujillo ◽  
...  

White-rot fungi are efficient lignin degraders due to the secretion of lignin peroxidase, manganese peroxidase, laccase, and versatile peroxidase (VP) on decayed wood. The VP is a high-redox-potential enzyme and could be used to detoxify reactive oxygen species (ROS), which accumulate in plants during biotic and abiotic stresses. We cloned the VP gene and expressed it via the Agrobacterium transformation procedure in transgenic tobacco plants to assay their tolerance to different abiotic stress conditions. Thirty independent T2 transgenic VP lines overexpressing the fungal Bjerkandera adustaVP gene were selected on kanamycin. The VP22, VP24, and VP27 lines showed significant manganese peroxidase (MnP) activity. The highest was VP22, which showed 10.87-fold more manganese peroxidase activity than the wild-type plants and led to a 34% increase in plant height and 28% more biomass. The VP22, VP24, and VP27 lines showed enhanced tolerance to drought, 200 mM NaCl, and 400 mM sorbitol. Also, these transgenics displayed significant tolerance to methyl viologen, an active oxygen-generating compound. The present data indicate that overproducing the VP gene in plants increases significantly their biomass and the abiotic stress tolerance. The VP enzyme is an effective biotechnological tool to protect organisms against ROS. In transgenic tobacco plants, it improves drought, salt, and oxidative stress tolerance. Thus, the VP gene represents a great potential for obtaining stress-tolerant crops.


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.


2012 ◽  
Vol 39 (12) ◽  
pp. 10201-10209 ◽  
Author(s):  
Luciana C. Cidade ◽  
Tahise M. de Oliveira ◽  
Amanda F. S. Mendes ◽  
Amanda F. Macedo ◽  
Eny I. S. Floh ◽  
...  

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. 


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.


2012 ◽  
Vol 19 (6) ◽  
pp. 2202-2211 ◽  
Author(s):  
Melina A. Talano ◽  
Débora C. Busso ◽  
Cintia E. Paisio ◽  
Paola S. González ◽  
Silvia A. Purro ◽  
...  

2015 ◽  
Vol 85 (1) ◽  
pp. 148-160 ◽  
Author(s):  
Alessandro Occhialini ◽  
Myat T. Lin ◽  
P. John Andralojc ◽  
Maureen R. Hanson ◽  
Martin A. J. Parry

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