scholarly journals Disrupting Flavone Synthase II Alters Lignin and Improves Biomass Digestibility

2017 ◽  
Vol 174 (2) ◽  
pp. 972-985 ◽  
Author(s):  
Pui Ying Lam ◽  
Yuki Tobimatsu ◽  
Yuri Takeda ◽  
Shiro Suzuki ◽  
Masaomi Yamamura ◽  
...  
Plant Science ◽  
2002 ◽  
Vol 163 (2) ◽  
pp. 253-263 ◽  
Author(s):  
Yukiko Ueyama ◽  
Ken-ichi Suzuki ◽  
Masako Fukuchi-Mizutani ◽  
Yuko Fukui ◽  
Kiyoshi Miyazaki ◽  
...  

1987 ◽  
Vol 42 (11-12) ◽  
pp. 1193-1199 ◽  
Author(s):  
K. Stich ◽  
G. Forkmann

Flowers of Sinningia (syn. Rechsteineria) cardinalis contain glycosides of the flavones apigenin (4′-OH) and luteolin (3′,4′-OH) respectively, and of the related 3-deoxyanthocyanidins apigeninidin and luteolinidin. Studies on substrate specificity of the key enzyme of flavonoid biosynthesis, chalcone synthase, revealed that the 3′,4′-hydroxylated flavonoids are formed by hydroxylation of flavonoid compounds rather than by incorporation of caffeoyl-CoA into the flavonoid skeleton during the condensation reaction. In fact, flavonoid 3′-hydroxylase activity could be demonstrat­ed in the microsomal fraction of the flower extracts. The enzyme catalyses hydroxylation of naringenin and apigenin in the 3′-position to eriodictyol and luteolin, respectively, with NADPH as cofactor. Besides flavanone 3′-hydroxylase a further NADPH-dependent enzyme activity (flavone synthase II) was observed in the microsomal fraction catalysing the oxidation of naringenin to apigenin and of eriodictyol to luteolin. The Cytochrome P-450 inhibitor ancymidol was found to abolish completely flavone synthase II activity, whereas flavonoid 3′-hydroxylase activity was not impaired.


2008 ◽  
Vol 3 (8) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Heidi Halbwirth ◽  
Gerlinde Muster ◽  
Karl Stich

Dahlia ( Dahlia variabilis) exists in a dazzling array of cultivars, showing red, orange, magenta, lilac, yellow and white flower color, which is exclusively based on the presence of flavonoids and biochemically related compounds. Red hues (red, orange, magenta, lilac) are a result of anthocyanin accumulation in varying concentration and composition, while a yellow color is based on the formation of 6′-deoxychalcones in the petals. Red dahlia pigments are all derived from pelargonidin and cyanidin. Delphinidin derivatives are not formed due to the absence of flavonoid 3′,5′-hydroxylase in dahlia petals, which provides an explanation for the lack of blue dahlia flowers. Orange, lilac and rose cultivars are characterized by a lower anthocyanin content compared to many red cultivars. We investigated 198 cultivars for the presence of flavonoid enzymes. The activities of chalcone isomerase (CHI), chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), flavanone 3-hydroxylase (FHT), flavone synthase II (FNSII), flavonol synthase (FLS) and flavonoid 3′-hydroxylase (F3′H) were demonstrated in enzyme preparations of dahlia petals. CHI accepted 6′-hydroxychalcones as substrates, but did not catalyze the conversion of 6′-deoxychalcones to the corresponding flavanones. White cultivars were frequently characterized by the lack of DFR activity, whereas in many yellow cultivars neither FHT nor DFR activity could be shown.


2005 ◽  
Vol 71 (12) ◽  
pp. 8241-8248 ◽  
Author(s):  
Effendi Leonard ◽  
Yajun Yan ◽  
Kok Hong Lim ◽  
Mattheos A. G. Koffas

ABSTRACT Flavones are plant secondary metabolites that have wide pharmaceutical and nutraceutical applications. We previously constructed a recombinant flavanone pathway by expressing in Saccharomyces cerevisiae a four-step recombinant pathway that consists of cinnamate-4 hydroxylase, 4-coumaroyl:coenzyme A ligase, chalcone synthase, and chalcone isomerase. In the present work, the biosynthesis of flavones by two distinct flavone synthases was evaluated by introducing a soluble flavone synthase I (FSI) and a membrane-bound flavone synthase II (FSII) into the flavanone-producing recombinant yeast strain. The resulting recombinant strains were able to convert various phenylpropanoid acid precursors into the flavone molecules chrysin, apigenin, and luteolin, and the intermediate flavanones pinocembrin, naringenin, and eriodictyol accumulated in the medium. Improvement of flavone biosynthesis was achieved by overexpressing the yeast P450 reductase CPR1 in the FSII-expressing recombinant strain and by using acetate rather than glucose or raffinose as the carbon source. Overall, the FSI-expressing recombinant strain produced 50% more apigenin and six times less naringenin than the FSII-expressing recombinant strain when p-coumaric acid was used as a precursor phenylpropanoid acid. Further experiments indicated that unlike luteolin, the 5,7,4′-trihydroxyflavone apigenin inhibits flavanone biosynthesis in vivo in a nonlinear, dose-dependent manner.


2014 ◽  
Vol 165 (3) ◽  
pp. 1315-1327 ◽  
Author(s):  
Pui Ying Lam ◽  
Fu-Yuan Zhu ◽  
Wai Lung Chan ◽  
Hongjia Liu ◽  
Clive Lo

2010 ◽  
Vol 71 (5-6) ◽  
pp. 508-514 ◽  
Author(s):  
Judith Fliegmann ◽  
Katarina Furtwängler ◽  
Georg Malterer ◽  
Corrado Cantarello ◽  
Göde Schüler ◽  
...  

2016 ◽  
Vol 7 ◽  
Author(s):  
Hiroshi Mizuno ◽  
Takayuki Yazawa ◽  
Shigemitsu Kasuga ◽  
Yuji Sawada ◽  
Hiroyuki Kanamori ◽  
...  

2018 ◽  
Vol 4 (2) ◽  
pp. 196-198 ◽  
Author(s):  
Rodrigo A. Contreras ◽  
Gustavo E. Zúñiga

The role of flavonoids in plant-environmental stress has many biotechnological applications, in this way Antarctic plants have an important potential for molecular farming. However, the concentration and exploitation of resource are highly restricted, for this reason the use of enzymatic machinery of the Antarctic plants have importance for in vitro flavonoid production for different biotechnological applications. Despite their potential applications, key enzymes for flavonoid biosynthesis are poorly studied in non-model plants. In this work, we studied the flavonoid key enzyme, flavone synthase II (FNS II) in C. quitensis. The results show a cooperative kinetic model for NADPH and naringenin. The temperature and pH stability assays show optimal temperature between 20-30 °C, with an operative range from 2 to 37 °C, pH stability shows an optimum of 7.0 to 8.0, with operative range from 3.0 to 8.0, demonstrating a big thermal and pH-stability, an interesting characteristic to in vitro production of flavones.


2009 ◽  
Vol 61 (4) ◽  
pp. 983-994 ◽  
Author(s):  
Yegang Du ◽  
Hung Chu ◽  
Mingfu Wang ◽  
Ivan K. Chu ◽  
Clive Lo

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