scholarly journals Functional Analysis of Genes GlaDFR1 and GlaDFR2 Encoding Dihydroflavonol 4-Reductase (DFR) in Gentiana lutea L. Var. Aurantiaca (M. Laínz) M. Laínz

2022 ◽  
Vol 2022 ◽  
pp. 1-23
Author(s):  
Tingting Yu ◽  
Guojun Han ◽  
Zhihui Luan ◽  
Changfu Zhu ◽  
Jinghua Zhao ◽  
...  

Anthocyanins are important pigments for flower color, determining the ornamental and economic values of horticultural plants. As a key enzyme in the biosynthesis of anthocyanidins, dihydroflavonol 4-reductase (DFR) catalyzes the reduction of dihydroflavonols to generate the precursors for anthocyanidins (i.e., leucoanthocyanidins) and anthocyanins. To investigate the functions of DFRs in plants, we cloned the GlaDFR1 and GlaDFR2 genes from the petals of Gentiana lutea var. aurantiaca and transformed both genes into Nicotiana tabacum by Agrobacterium-mediated leaf disc method. We further investigated the molecular and phenotypic characteristics of T1 generation transgenic tobacco plants selected based on the hygromycin resistance and verified by both PCR and semiquantitative real-time PCR analyses. The phenotypic segregation was observed in the flower color of the transgenic tobacco plants, showing petals darker than those in the wild-type (WT) plants. Results of high-performance liquid chromatography (HPLC) analysis showed that the contents of gentiocyanin derivatives were decreased in the petals of transgenic plants in comparison to those of WT plants. Ours results revealed the molecular functions of GlaDFR1 and GlaDFR2 in the formation of coloration, providing solid theoretical foundation and candidate genes for further genetic improvement in flower color of plants.

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.


2005 ◽  
Vol 14 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Helga Schinkel ◽  
Andreas Schiermeyer ◽  
Raphael Soeur ◽  
Rainer Fischer ◽  
Stefan Schillberg

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.


2015 ◽  
Vol 24 (6) ◽  
pp. 945-953 ◽  
Author(s):  
Selcuk Aslan ◽  
Per Hofvander ◽  
Paresh Dutta ◽  
Chuanxin Sun ◽  
Folke Sitbon

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