scholarly journals Cloning and Functional Characterization of Dihydroflavonol 4-Reductase Gene Involved in Anthocyanidin Biosynthesis of Grape Hyacinth

2019 ◽  
Vol 20 (19) ◽  
pp. 4743 ◽  
Author(s):  
Hongli Liu ◽  
Qian Lou ◽  
Junren Ma ◽  
Beibei Su ◽  
Zhuangzhuang Gao ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Flower Colour ◽  
Flower Color ◽  
Color Variation ◽  
Blue Flower ◽  
Blue Color ◽  
Color Development ◽  
High Preference ◽  
Grape Hyacinth

Grape hyacinth (Muscari spp.) is a popular ornamental plant with bulbous flowers noted for their rich blue color. Muscari species have been thought to accumulate delphinidin and cyanidin rather than pelargonidin-type anthocyanins because their dihydroflavonol 4-reductase (DFR) does not efficiently reduce dihydrokaempferol. In our study, we clone a novel DFR gene from blue flowers of Muscari. aucheri. Quantitative real-time PCR (qRT-PCR) and anthocyanin analysis showed that the expression pattern of MaDFR had strong correlations with the accumulation of delphinidin, relatively weak correlations with cyanidin, and no correations with pelargonidin. However, in vitro enzymatic analysis revealed that the MaDFR enzyme can reduce all the three types of dihydroflavonols (dihydrokaempferol, dihydroquercetin, and dihydromyricetin), although it most preferred dihydromyricetin as a substrate to produce leucodelphinidin, the precursor of blue-hued delphinidin. This indicated that there may be other functional genes responsible for the loss of red pelargonidin-based pigments in Muscari. To further verify the substrate-specific selection domains of MaDFR, an assay of amino acid substitutions was conducted. The activity of MaDFR was not affected whenever the N135 or E146 site was mutated. However, when both of them were mutated, the catalytic activity of MaDFR was lost completely. The results suggest that both the N135 and E146 sites are essential for the activity of MaDFR. Additionally, the heterologous expression of MaDFR in tobacco (Nicotiana tabacum) resulted in increasing anthocyanin accumulation, leading to a darker flower color, which suggested that MaDFR was involved in color development in flowers. In summary, MaDFR has a high preference for dihydromyricetin, and it could be a powerful candidate gene for genetic engineering for blue flower colour modification. Our results also make a valuable contribution to understanding the basis of color variation in the genus Muscari.

scholarly journals Newly Elucidated Mechanism for Blue Flower Color Development

1996 ◽  
Vol 54 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Tadao KONDO ◽  
Minoru UEDA ◽  
Kumi YOSHIDA
Keyword(s):  
Flower Color ◽  
Blue Flower ◽  
Color Development

Structure of anthocyanin from the blue petals of Phacelia campanularia and its blue flower color development

2006 ◽  
Vol 67 (6) ◽  
pp. 622-629 ◽  
Author(s):  
Mihoko Mori ◽  
Tadao Kondo ◽  
Kenjiro Toki ◽  
Kumi Yoshida
Keyword(s):  
Flower Color ◽  
Blue Flower ◽  
Color Development ◽  
Phacelia Campanularia

scholarly journals The Use of Recycled Waste Paper as an Al Source for Blue-flowering Hydrangea

HortScience ◽  
1998 ◽  
Vol 33 (4) ◽  
pp. 604b-604
Author(s):  
K.M. Ryan ◽  
J.H. Edwards ◽  
C.H. Gilliam ◽  
G.J. Keever
Keyword(s):  
Waste Paper ◽  
Aluminum Concentration ◽  
Blue Flower ◽  
Blue Color ◽  
Time Control ◽  
Color Development ◽  
Hydrangea Macrophylla ◽  
The Media ◽  
Recycled Waste ◽  
Recycled Waste Paper

Blue color development in Hydrangea macrophylla is usually accomplished by applying Al as an alum drench. Drenches are applied during forcing 10–14 days after transplanting at a rate of 17,500 mg·L-1. Cultivars Blue Wave and Nikko Blue were used to evaluate if the Al contained in waste paper can provide the necessary Al for blue flower development. Two waste paper forms, pelletized and crumble, were used as surface mulches and as media amendments. The amendments were incorporated into the media at transplanting and mulches were applied either at transplanting or 28 days later. Alum drenching was initiated at transplanting as a control. Leachates were collected weekly using the VTEM. Total Al, electrical conductivity, and pH were determined on all samples. All waste paper treatments resulted in pink flowers in both cultivars. Leachate pH, from plants in this test, was >6.5. Aluminum concentration was greater than the 15 mg·L-1 Al needed for blue color development in flowers, but Al concentration decreased with time. Control of pH at the waste paper surface and in the media is critical for increasing the availability of labile Al for uptake by hydrangea.

ChemInform Abstract: Newly Elucidated Mechanism for Blue Flower Color Development

ChemInform ◽  
2010 ◽  
Vol 27 (33) ◽  
pp. no-no
Author(s):  
T. KONDO ◽  
M. UEDA ◽  
K. YOSHIDA
Keyword(s):  
Flower Color ◽  
Blue Flower ◽  
Color Development

Insights into the biochemical and functional characterization of sortase E transpeptidase of Corynebacterium glutamicum

2019 ◽  
Vol 476 (24) ◽  
pp. 3835-3847 ◽  
Author(s):  
Aliyath Susmitha ◽  
Kesavan Madhavan Nampoothiri ◽  
Harsha Bajaj
Keyword(s):  
Protein Engineering ◽  
Cell Attachment ◽  
Functional Characterization ◽  
Protein Structures ◽  
Structural Similarity ◽  
Surface Proteins ◽  
Sortase A ◽  
Peptide Cleavage ◽  
New Findings

Most Gram-positive bacteria contain a membrane-bound transpeptidase known as sortase which covalently incorporates the surface proteins on to the cell wall. The sortase-displayed protein structures are involved in cell attachment, nutrient uptake and aerial hyphae formation. Among the six classes of sortase (A–F), sortase A of S. aureus is the well-characterized housekeeping enzyme considered as an ideal drug target and a valuable biochemical reagent for protein engineering. Similar to SrtA, class E sortase in GC rich bacteria plays a housekeeping role which is not studied extensively. However, C. glutamicum ATCC 13032, an industrially important organism known for amino acid production, carries a single putative sortase (NCgl2838) gene but neither in vitro peptide cleavage activity nor biochemical characterizations have been investigated. Here, we identified that the gene is having a sortase activity and analyzed its structural similarity with Cd-SrtF. The purified enzyme showed a greater affinity toward LAXTG substrate with a calculated KM of 12 ± 1 µM, one of the highest affinities reported for this class of enzyme. Moreover, site-directed mutation studies were carried to ascertain the structure functional relationship of Cg-SrtE and all these are new findings which will enable us to perceive exciting protein engineering applications with this class of enzyme from a non-pathogenic microbe.

Relationship Between the Composition of Anthocyanins and Flower Color Variation in Hardy Water Lily (Nymphaea spp.) Cultivars

2013 ◽  
Vol 47 (5) ◽  
pp. 437-453
Author(s):  
Zhu Manlan ◽  
Wang Liangsheng ◽  
Zhang Huijin ◽  
Xu Yanjun ◽  
Zheng Xuchen ◽  
...  
Keyword(s):  
Flower Color ◽  
Color Variation ◽  
Water Lily

Novel Toxin-antitoxin System Xn-mazEF from Xenorhabdus nematophi-la: Identification, Characterization and Functional Exploration

2020 ◽  
Vol 16 ◽  
Author(s):  
Jogendra Singh Nim ◽  
Mohit Yadav ◽  
Lalit Kumar Gautam ◽  
Chaitali Ghosh ◽  
Shakti Sahi ◽  
...  
Keyword(s):  
Interaction Analysis ◽  
Functional Characterization ◽  
Host Cells ◽  
System Control ◽  
Xenorhabdus Nematophila ◽  
Functional Features ◽  
Dynamics Simulations ◽  
Species Specific ◽  
Rna Interaction

Background: Xenorhabdus nematophila maintains species-specific mutual interaction with nematodes of Steinernema genus. Type II Toxin Antitoxin (TA) systems, the mazEF TA system controls stress and programmed cell death in bacteria. Objective: This study elucidates the functional characterization of Xn-mazEF, a mazEF homolog in X. nematophila by computational and in vitro approaches. Methods: 3 D- structural models for Xn-MazE toxin and Xn-MazF antitoxin were generated, validated and characterized for protein - RNA interaction analysis. Further biological and cellular functions of Xn-MazF toxin were also predicted. Molecular dynamics simulations of 50ns for Xn-MazF toxin complexed with nucleic acid units (DU, RU, RC, and RU) were performed. The MazF toxin and complete MazEF operon were endogenously expressed and monitored for the killing of Escherichia coli host cells under arabinose induced tightly regulated system. Results: Upon induction, E. coli expressing toxin showed rapid killing within four hours and attained up to 65% growth inhibition, while the expression of the entire operon did not show significant killing. The observation suggests that the Xn-mazEF TA system control transcriptional regulation in X. nematophila and helps to manage stress or cause toxicity leading to programmed death of cells. Conclusion: The study provides insights into structural and functional features of novel toxin, XnMazF and provides an initial inference on control of X. nematophila growth regulated by TA systems.

scholarly journals Functional identification of ygiP as a positive regulator of the ttdA-ttdB-ygjE operon

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2129-2135 ◽  
Author(s):  
Taku Oshima ◽  
Francis Biville
Keyword(s):  
Functional Characterization ◽  
Anaerobic Growth ◽  
Functional Identification ◽  
New Members ◽  
E Coli ◽  
Inner Membrane Protein ◽  
Tartrate Dehydratase

Functional characterization of unknown genes is currently a major task in biology. The search for gene function involves a combination of various in silico, in vitro and in vivo approaches. Available knowledge from the study of more than 21 LysR-type regulators in Escherichia coli has facilitated the classification of new members of the family. From sequence similarities and its location on the E. coli chromosome, it is suggested that ygiP encodes a lysR regulator controlling the expression of a neighbouring operon; this operon encodes the two subunits of tartrate dehydratase (TtdA, TtdB) and YgiE, an integral inner-membrane protein possibly involved in tartrate uptake. Expression of tartrate dehydratase, which converts tartrate to oxaloacetate, is required for anaerobic growth on glycerol as carbon source in the presence of tartrate. Here, it has been demonstrated that disruption of ygiP, ttdA or ygjE abolishes tartrate-dependent anaerobic growth on glycerol. It has also been shown that tartrate-dependent induction of the ttdA-ttdB-ygjE operon requires a functional YgiP.

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