Flower colour and cytochromes P450<sup><sup>†</sup></sup>

Yoshikazu Tanaka

Filippa Brugliera

^{Institute for Plant Science, Suntory Business Expert Ltd., Shimamoto, Osaka 618-8503, Japan}

^{Florigene Pty Ltd., Melbourne, Victoria 3083, Australia}

e-mail: pj.oc.yrotnus@akanat_uzakihsoy

^{We dedicate this review to the memory of Michael Dalling. A man of vision, passion and inspiration.}

One contribution of 9 to a Theme Issue ‘Cytochrome P450 and its impact on planet Earth’.

Abstract

Cytochromes P450 play important roles in biosynthesis of flavonoids and their coloured class of compounds, anthocyanins, both of which are major floral pigments. The number of hydroxyl groups on the B-ring of anthocyanidins (the chromophores and precursors of anthocyanins) impact the anthocyanin colour, the more the bluer. The hydroxylation pattern is determined by two cytochromes P450, flavonoid 3′-hydroxylase (F3′H) and flavonoid 3′,5′-hydroxylase (F3′5′H) and thus they play a crucial role in the determination of flower colour. F3′H and F3′5′H mostly belong to CYP75B and CYP75A, respectively, except for the F3′5′Hs in Compositae that were derived from gene duplication of CYP75B and neofunctionalization. Roses and carnations lack blue/violet flower colours owing to the deficiency of F3′5′H and therefore lack the B-ring-trihydroxylated anthocyanins based upon delphinidin. Successful redirection of the anthocyanin biosynthesis pathway to delphinidin was achieved by expressing F3′5′H coding regions resulting in carnations and roses with novel blue hues that have been commercialized. Suppression of F3′5′H and F3′H in delphinidin-producing plants reduced the number of hydroxyl groups on the anthocyanidin B-ring resulting in the production of monohydroxylated anthocyanins based on pelargonidin with a shift in flower colour to orange/red. Pelargonidin biosynthesis is enhanced by additional expression of a dihydroflavonol 4-reductase that can use the monohydroxylated dihydrokaempferol (the pelargonidin precursor). Flavone synthase II (FNSII)-catalysing flavone biosynthesis from flavanones is also a P450 (CYP93B) and contributes to flower colour, because flavones act as co-pigments to anthocyanins and can cause blueing and darkening of colour. However, transgenic plants expression of a FNSII gene yielded paler flowers owing to a reduction of anthocyanins because flavanones are precursors of anthocyanins and flavones.

Keywords: anthocyanin, anthocyanidin, flavonoid, flavonoid 3′-hydroxylase, flavonoid 3′,5′-hydroxylase, flavone synthase

Abstract

Acknowledgements

The authors are grateful to all colleagues in Suntory Holdings Ltd. (Japan) and Florigene Pty Ltd (Australia), Florigene Europe (the Netherlands) and Paso de Luna (Colombia). Dr David Nelson is acknowledged for his contribution to P450 nomenclature for many years. The photo of figure 4c was kindly provided by Dr Okuhara from his wedding.

Acknowledgements

References

1. Tanaka Y, Sasaki N, Ohmiya A. 2008 Plant pigments for coloration: anthocyanins, betalains and carotenoids. Plant J.54, 733–74910.1111/j.1365-313X.2008.03447.x () [] [[PubMed][Google Scholar]
2. Yoshida K, Mori M, Kondo T. 2009 Blue flower color development by anthocyanins: from chemical structure to cell physiology. Nat. Prod. Rep.26, 884–91510.1039/B800165K () [] [[PubMed][Google Scholar]
3. Honda T, Saito N. 2002 Recent progress in the chemistry of polyacylated anthocyanins as flower color pigment. Heterocycles56, 633–69210.3987/REV-01-SR(K)2 () [[PubMed][Google Scholar]
4. Tanaka Y. 2006 Flower colour and cytochromes P450. Phytochem. Rev.5, 283–29110.1007/s11101-006-9003-7 () [[PubMed][Google Scholar]
5. Shiono M, Matsugaki N, Takeda K. 2005 Phytochemistry: structure of the blue cornflower pigment. Nature436, 791.10.1038/436791a () [] [[PubMed][Google Scholar]
6. Yoshida K, Kondo T, Okazaki Y, Katou K. 1995 Cause of blue petal colour. Nature373, 291.10.1038/373291a0 () [[PubMed][Google Scholar]
7. Rausher MD. 2006 The evolution of flavonoids and their genes. In The science of flavonoids (ed. Grotewold E, editor. ), pp. 175–211 Berlin, Germany: Springer [PubMed][Google Scholar]
8. Stotz G, Forkmann G. 1981 Hydroxylation of the B-ring of flavonoids in the 3 - and 5-position with enzyme extracts from flowers of Verbena hybrida. Z. Naturforsch.37c, 19–23 [PubMed][Google Scholar]
9. Menting JGT, Scopes RK, Stevenson TW. 1994 Characterization of flavonoid 3′, 5′-hydroxylases in microsomal membrane fraction of Petunia hybrida flowers. Plant Physiol.106, 633–64210.1104/pp.106.2.633 () ] [[PubMed][Google Scholar]
10. Holton TA, et al. 1993. Cloning and expression of cytochrome P450 genes controlling flower colour. Nature366, 276–27910.1038/366276a0 () [] [[PubMed]
11. de Vetten N, ter Horst J, van Schaik HP, de Boer A, Mol J, Koes R. 1999 A cytochrome b5 is required for full activity of flavonoid 3′, 5′-hydroxylase, a cytochrome P450 involved in the formation of blue flower colors. Proc. Natl Acad. Sci. USA96, 778–78310.1073/pnas.96.2.778 () ] [[PubMed][Google Scholar]
12. Forkman G, Ruhnau B. 1987 Distinct substrate specificity of dihydroflavonol 4-reductase from flowers of Petunia hybrida. Z. Naturforsch.42C, 1146–1148 [PubMed][Google Scholar]
13. Winkel BSJ. 2004 Metabolic channeling in plants. Annu. Rev. Plant Biol.55, 85–10710.1146/annurev.arplant.55.031903.141714 () [] [[PubMed][Google Scholar]
14. Brugliera F, Barri-Rewell G, Holton TA, Mason JG. 1999 Isolation and characterization of a flavonoid 3′-hydroxylase cDNA clone corresponding to the Ht1 locus of Petunia hybrida. Plant J.19, 441–45110.1046/j.1365-313X.1999.00539.x () [] [[PubMed][Google Scholar]
15. Ueyama U, Suzuki K, Fukuchi-Mizutani M, Fukui Y, Miyazaki K, Ohkawa H, Kusumi T, Tanaka Y. 2002 Molecular and biochemical characterization of torenia flavonoid 3′-hydroxylase and flavone synthase II and modification of flower color by modulating the expression of these genes. Plant Sci.163, 253–26310.1016/S0168-9452(02)00098-5 () [[PubMed][Google Scholar]
16. Nelson D, Werck-Reichhart D. 2011 A P450-centric view of plant evolution. Plant J.66, 194–21110.1111/j.1365-313X.2011.04529.x () [] [[PubMed][Google Scholar]
17. Seitz C, Eder C, Deiml B, Kellner S, Martens S, Forkmann G. 2006 Cloning, functional identification and sequence analysis of flavonoid 3′-hydroxylase and flavonoid 3′,5′-hydroxylase cDNAs reveals independent evolution of flavonoid 3′,5′-hydroxylase in the Asteraceae family. Plant Mol. Biol.61, 365–38110.1007/s11103-006-0012-0 () [] [[PubMed][Google Scholar]
18. Seitz C, Ameres S, Forkmann G. 2007 Identification of the molecular basis for the functional difference between flavonoid 3′-hydroxylase and flavonoid 3′,5′-hydroxylase. FEBS Lett.581, 3429–343410.1016/j.febslet.2007.06.045 () [] [[PubMed][Google Scholar]
19. Ishiguro K, Masumi T, Tanaka Y. 2012 Functional analysis of Antirrhinum kelloggii flavonoid 3′-hydroxylase and flavonoid 3′,5′-hydroxylase genes; critical role in flower color and evolution in the genus Antirrhinum. J. Plant Res.125, 451–45610.1007/s10265-011-0455-5 () [] [[PubMed][Google Scholar]
20. Falginella L, Castellarin SD, Testolin R, Gambetta GA, Morgante M, Di Gaspero G. 2010 Expansion and subfunctionalisation of flavonoid 3′,5′-hydroxylases in the grapevine lineage. BMC Genomics11, 562.10.1186/1471-2164-11-562 () ] [[PubMed][Google Scholar]
21. Rausher MD. 2008 Evolutionary transitions in floral color. Int. J. Plant Sci.169, 7–2110.1086/523358 () [[PubMed][Google Scholar]
22. Hoshino A, Morita Y, Choi JD, Saito N, Toki K, Tanaka Y, Iida S. 2003 Spontaneous mutations of the flavonoid 3′-hydroxylase gene conferring reddish flowers in the three morning glory species. Plant Cell Physiol.44, 990–100110.1093/pcp/pcg143 () [] [[PubMed][Google Scholar]
23. Zufall RA, Rausher MD. 2003 The genetic basis of a flower color polymorphism in the common morning glory (Ipomoea purpurea). J. Hered.94, 442–44810.1093/jhered/esg098 () [] [[PubMed][Google Scholar]
24. Nakatsuka T, Nishihara M, Mishiba K, Hirano H, Yamamura S. 2006 Two different transposable elements inserted in flavonoid 3′,5′-hydroxylase gene contribute to pink flower coloration in Gentiana scabra. Mol. Genet. Genomics275, 231–24110.1007/s00438-005-0083-7 () [] [[PubMed][Google Scholar]
25. Sato M, Kawabe T, Hosokawa M, Tatsuzawa F, Doi M. 2011 Tissue culture-induced flower-color changes in Saintpaulia caused by excision of the transposon inserted in the flavonoid 3′, 5′ hydroxylase (F3′5′H) promoter. Plant Cell Rep.30, 929–93910.1007/s00299-011-1016-z () [] [[PubMed][Google Scholar]
26. Takahashi R, Dubouzet JG, Matsumura H, Yasuda K, Iwashina T. 2010 A new allele of flower color gene W1 encoding flavonoid 3′5′-hydroxylase is responsible for light purple flowers in wild soybean Glycine soja. BMC Plant Biol.10, 155.10.1186/1471-2229-10-155 () ] [[PubMed][Google Scholar]
27. Toda K, Yang D, Yamanaka N, Watanabe S, Harada K, Takahashi R. 2002 A single-base deletion in soybean flavonoid 3′-hydroxylase gene is associated with gray pubescence color. Plant Mol. Biol.50, 187–19610.1023/A:1016087221334 () [] [[PubMed][Google Scholar]
28. Hopkins R, Rausher MD. 2011 Identification of two genes causing reinforcement in the Texas wildflower Phlox drummondii. Nature469, 411–41410.1038/nature09641 () [] [[PubMed][Google Scholar]
29. Martens S, Forkmann G, Britsch L, Wellmann F, Matern U, Lukacin R. 2003 Divergent evolution of flavonoid 2-oxoglutarate-dependent dioxygenases in parsley. FEBS Lett.544, 93–9810.1016/S0014-5793(03)00479-4 () [] [[PubMed][Google Scholar]
30. Stotz G, Forkmann G. 1981 Oxidation of flavanones to flavones with flower extracts of Antirrhinum majus (snapdragon). Z. Naturforsch.36c, 737–741 [PubMed][Google Scholar]
31. Akashi T, Aoki T, Ayabe S. 1998 Identification of a cytochrome P450 cDNA encoding (2S)-flavanone2-hydroxylase of licorice (Glycyrrhiza echinata L.; Fabaceae) which represents licodione synthase and flavone synthase II. FEBS Lett.431, 287–29010.1016/S0014-5793(98)00781-9 () [] [[PubMed][Google Scholar]
32. Akashi T, Fukuchi-Mizutani M, Aoki T, Ueyama Y, Yonekura-Sakakibara K, Tanaka Y, Kusumi T, Ayabe S. 1999 Molecular cloning and biochemical characterization of a novel cytochrome P450, flavone synthase II, that catalyzes direct conversion of flavanones to flavones. Plant Cell Physiol.40, 1182–1186) () [[PubMed][Google Scholar]
33. Martens S, Forkmann G. 1999 Cloning and expression of flavone synthase II from Gerbera hybrids. Plant J.20, 611–61810.1046/j.1365-313X.1999.00636.x () [] [[PubMed][Google Scholar]
34. Du Y, Chu H, Chu IK, Lo C. 2010 CYP93G2 is a flavanone 2-hydroxylase required for C-glycosylflavone biosynthesis in rice. Plant Physiol.154, 324–33310.1104/pp.110.161042 () ] [[PubMed][Google Scholar]
35. Brazier-Hicks M, Evans KM, Gershater MC, Puschmann H, Steel PG, Edwards R. 2009 The C-glycosylation of flavonoids in cereals. J. Biol. Chem.284, 17926–1793410.1074/jbc.M109.009258 () ] [[PubMed][Google Scholar]
36. Yabuya T, Nakamura M, Iwashina T, Yamaguchi M, Takehara T. 1997 Anthocyanin-flavone copigmentaion in bluish purple flowers of Japanese garden iris (Irsi ensata Thunb.). Euphytica98, 163–16710.1023/A:1003152813333 () [[PubMed][Google Scholar]
37. Fukui Y, Tanaka Y, Kusumi T, Iwashita T, Nomoto K. 2003 A rationale for the shift in colour towards blue in transgenic carnation flowers expressing the flavonoid 3′,5′-hydroxylase gene. Phytochemistry63, 15–2310.1016/S0031-9422(02)00684-2 () [] [[PubMed][Google Scholar]
38. Akashi T, Aoki T, Ayabe S. 1999 Cloning and functional expression of a cytochrome P450 cDNA encoding 2-hydroxyisoflavanone synthase involved in biosynthesis of the isoflavonoid skeleton in licorice. Plant Physiol.121, 821–82810.1104/pp.121.3.821 () ] [[PubMed][Google Scholar]
39. Steele CL, Gijzen M, Qutob D, Dixon RA. 1999 Molecular characterization of the enzyme catalyzing the aryl migration reaction of isoflavonoid biosynthesis in soybean. Arch. Biochem. Biophys.367, 146–15010.1006/abbi.1999.1238 () [] [[PubMed][Google Scholar]
40. Jung W, Yu O, Lau SM, O'Keefe DP, Odell J, Fader G, McGonigle B. 2000 Identification and expression of isoflavone synthase, the key enzyme for biosynthesis of isoflavones in legumes. Nat. Biotechnol.18, 208–21210.1038/72671 () [] [[PubMed][Google Scholar]
41. Tanaka Y, Brugliera F, Chandler S. 2009 Recent progress of flower colour modification by biotechnology. Int. J. Mol. Sci.10, 5350–536910.3390/ijms10125350 () ] [[PubMed][Google Scholar]
42. Wesley SV, Helliwell CA, Smith NA. 2001 Construct design for efficient, effective and high-throughput gene silencing in plants. Plant J.27, 581–59010.1046/j.1365-313X.2001.01105.x () [] [[PubMed][Google Scholar]
43. Wang M-B, Waterhouse PM. 2001 Application of gene silencing in plants. Curr. Opin. Plant Biol.5, 146–15010.1016/S1369-5266(02)00236-4 () [] [[PubMed][Google Scholar]
44. Nakamura N, Fukuchi-Mizutani M, Suzuki K, Miyazaki K, Tanaka Y. 2006 RNAi suppression of the anthocyanidin synthase gene in Torenia hybrida yields white flowers with higher frequency and better stability than antisense and sense suppression. Plant Biotechnol.23, 13–1810.5511/plantbiotechnology.23.13 () [[PubMed][Google Scholar]
45. Tanaka Y, Brugliera F, Kalc G, Senior M, Dyson B, Nakamura N, Katsumoto Y, Chandler S. 2010 Flower color modification by engineering of the flavonoid biosynthetic pathway: practical perspectives. Biosci. Biotechnol. Biochem.74, 1760–176910.1271/bbb.100358 () [] [[PubMed][Google Scholar]
46. Tanaka Y, Ohmiya A. 2008 Seeing is believing: engineering anthocyanin and carotenoid biosynthetic pathways. Curr. Opin. Biotechnol.19, 190–19710.1016/j.copbio.2008.02.015 () [] [[PubMed][Google Scholar]
47. Nishihara M, Nakatsuka T. 2011 Genetic engineering of flavonoid pigments to modify flower color in floricultural plants. Biotechnol. Lett.33, 433–44110.1007/s10529-010-0461-z () [] [[PubMed][Google Scholar]
48. Comai L, Moran P, Maslyar D. 1990 Novel and useful properties of a chimeric plant promoter combining CaMV35S and MAS elements.Plant Mol. Biol.15, 373–38110.1007/BF00019155 () [] [[PubMed]
49. Holton TA, Tanaka Y.1994. Transgenic flowering plants. International Patent Publication number WO94/28140.
50. Shimada Y, Nakano-Shimada R, Ohbayashi M, Okinaka Y, Kiyokawa S, Kikuchi Y. 1999 Expression of chimeric P450 genes encoding flavonoid-3′, 5′-hydroxylase in transgenic tobacco and petunia plants. FEBS Lett.461, 241–24510.1016/S0014-5793(99)01425-8 () [] [[PubMed][Google Scholar]
51. Mori S, Kobayashi H, Hoshi Y, Kondo M, Nakano M. 2004 Heterologous expression of the flavonoid 3′,5′-hydroxylase gene of Vinca major alters flower color in transgenic Petunia hybrida. Plant Cell Rep.22, 415–42110.1007/s00299-003-0709-3 () [] [[PubMed][Google Scholar]
52. Okinaka Y, Shimada Y, Nakano-Shimada R, Ohbayashi M, Kiyokawa S, Kikuchi Y. 2003 Selective accumulation of delphinidin derivatives in tobacco using a putative flavonoid 3′,5′-hydroxylase cDNA from Campanula medium. Biosci. Biotechnol. Biochem.67, 161–16510.1271/bbb.67.161 () [] [[PubMed][Google Scholar]
53. Togami J, et al. 2006. Molecular characterization of the flavonoid biosynthesis of Verbena hybrida and the functional analysis of verbena and Clitoria ternatea F3′5′H genes in transgenic verbena. Plant Biotechnol.23, 5–1110.5511/plantbiotechnology.23.5 () [[PubMed]
54. Tsuda S, et al. 2004. Flower color modification of Petunia hybrida commercial varieties by metabolic engineering. Plant Biotechnol.21, 377–38610.5511/plantbiotechnology.21.377 () [[PubMed]
55. Bloor SJ. 1998 A macrocyclic anthocyanin from red/mauve carnation flowers. Phytochemistry49, 225–22810.1016/S0031-9422(97)01051-0 () [[PubMed][Google Scholar]
56. Gonnet J-F, Fenet B. 2000 ‘Cyclamen red’ color based on a macrocyclic anthocyanin in carnation flowers. J. Agric. Food Chem.48, 22–2510.1021/jf9907642 () [] [[PubMed][Google Scholar]
57. Holton TA.1996. Transgenic plants exhibiting altered flower colour and methods for producing same. International Patent Publication number WO96/36716.
58. Mol J, Cornish E, Mason J, Koes R. 1999 Novel coloured flowers. Curr. Opin. Biotechnol.10, 198–20110.1016/S0958-1669(99)80035-4 () [] [[PubMed][Google Scholar]
59. Brugliera F, Tanaka Y, Mason J.2004. Flavonoid 3′,5′-hydroxylase gene sequences and uses therefor. International Patent Publication number WO/2004/020637.
60. Brugliera F, Tull D, Holton TA, Karan M, Treloar N, Simpson K, Skurczynska J, Mason JG. 2000 Introduction of a cytochrome b5 enhances the activity of flavonoid 3′,5′-hydroxylase (a cytochrome P450) in transgenic carnation. Int. Plant Mol. Biol. Rep. (Suppl.)18, S6–S8 [PubMed]
61. Tanaka Y, Katsumoto Y, Brugliera F, Mason J. 2005 Genetic engineering in floriculture. Plant Cell Tissue Org.80, 1–2410.1007/s11240-004-0739-8 () [[PubMed][Google Scholar]
62. Brugliera F.2009. Genetically modified plants with altered inflorescence. International Patent Publication number WO/2009/062259.
63. Brugliera F.2010. A plant with altered inflorescence. International Patent Publication number WO/2010/069004.
64. Mikanagi Y, Yokoi M, Ueda Y, Saito N. 1995 Flower flavonol and anthocyanin distribution in subgenus Rosa. Biochem. Syst. Ecol.23, 183–20010.1016/0305-1978(95)93849-X () [[PubMed][Google Scholar]
65. Mikanagi Y, Saito N, Yokoi M, Tatsuzawa F. 2000 Anthocyanins in flowers of genus Rosa, sections Cinnamomeae (=Rosa), Chinenses, Gallicanae and some modern garden roses. Biochem. Syst. Ecol.28, 887–90210.1016/S0305-1978(99)00127-1 () [] [[PubMed][Google Scholar]
66. Katsumoto Y, et al. 2007. Engineering of the rose flavonoid biosynthetic pathway successfully generated blue-hued flowers accumulating delphinidin. Plant Cell Physiol.48, 1589–160010.1093/pcp/pcm131 () [] [[PubMed]
67. Nakamura N, et al. 2011. Environmental risk assessment and field performance of rose (Rosa x hybrida) genetically modified for delphinidin production. Plant Biotechnol.28, 251–26110.5511/plantbiotechnology.11.0113a () [[PubMed]
68. Nakamura N, Tems U, Fukuchi-Mizutani M, Chandler S, Matsuda Y, Takeuchi S, Matsumoto S, Tanaka Y. 2011 Molecular based evidence for a lack of gene-flow between Rosa x hybrida and wild Rosa species in Japan. Plant Biotechnol.28, 245–25010.5511/plantbiotechnology.10.1217a () [[PubMed][Google Scholar]
69. Johnson ET, Yi H, Shin B, Oh B-J, Cheong H, Choi G. 1999 Cymbidium hybrida dihydroflavonol 4-reductase does not efficiently reduce dihydrokaempferol to produce orange pelargonidin-type anthocyanins. Plant J.19, 81–8510.1046/j.1365-313X.1999.00502.x () [] [[PubMed][Google Scholar]
70. Seitz C, Vitten M, Steinbach P, Hartl S, Hirsche J, Rhthje W, Treutter D, Forkmann G. 2007 Redirection of anthocyanin synthesis in Osteospermum hybrida by a two-enzyme manipulation strategy. Phytochemistry68, 824–83310.1016/j.phytochem.2006.12.012 () [] [[PubMed][Google Scholar]
71. Schwinn KE, Markham KR, Giveno N. 1993 Floral flavonoids and the potential for pelargonidin biosynthesis in commercial chrysanthemum cultivars. Phytochemistry35, 145–15010.1016/S0031-9422(00)90523-5 () [[PubMed][Google Scholar]
72. Meyer P, Heidemann I, Forkmann G, Saedler H. 1987 A new petunia flower colour generated by transformation of a mutant with a maze gene. Nature330, 677–67810.1038/330677a0 () [] [[PubMed][Google Scholar]
73. Helariutta Y, Elomaa P, Kotilainen H, Seppanen P, Teeri TH. 1993 Cloning of cDNA for dihydroflavonol 4-reductase (DFR) and charaterization of dfr expression in the corollas of Gerbera hybrida var. Regina (Compositae). Plant Mol. Biol.22, 183–19310.1007/BF00014927 () [] [[PubMed][Google Scholar]
74. Tanaka Y, Fukui Y, Fukuchi-Mizutani M, Holton TA, Higgins E, Kusumi T. 1995 Molecular cloning and characterization of Rosa hybrida dihydroflavonol 4-reductase. Plant Cell Physiol.36, 1023–1031 [[PubMed][Google Scholar]
75. Nakatsuka T, Abe Y, Kakizaki Y, Yamamura S, Nishihara M. 2007 Production of red-flowered plants by genetic engineering of multiple flavonoid biosynthetic genes. Plant Cell Rep.26, 1951–195910.1007/s00299-007-0401-0 () [] [[PubMed][Google Scholar]
76. Ueyama Y, Katsumoto Y, Fukui Y, Fukuchi-Mizutani M, Ohkawa H, Kusumi T, Iwashita T, Tanaka Y. 2006 Molecular characterization of the flavonoid biosynthetic pathway and flower color modification of Nierembergia sp. Plant Biotechnol.23, 19–2410.5511/plantbiotechnology.23.19 () [[PubMed][Google Scholar]
77. Nakamura N, Fukuchi-Mizutani M, Fukui Y, Ishiguro K, Suzuki K, Tanaka Y. 2010 Generation of red flower varieties from blue Torenia hybrida by redirection of the flavonoid pathway from delphinidin to pelargonidin. Plant Biotechnol.27, 375–38310.5511/plantbiotechnology.10.0610a () [[PubMed][Google Scholar]
78. Boase MR, Lewis DH, Davies KM, Marshall GB, Patel D, Schwinn KE, Deroles SC. 2010 Isolation and antisense suppression of flavonoid 3′, 5′-hydroxylase modifies flower pigments and colour in cyclamen. BMC Plant Biol.10, 107.10.1186/1471-2229-10-107 () ] [[PubMed][Google Scholar]
79. Nakatsuka T, Mishiba K, Abe Y, Kubota A, Kakizaki Y, Yamamura S, Nishihara M. 2008 Flower color modification of gentian plants by RNAi-mediated gene silencing. Plant Biotechnol.25, 61–6810.5511/plantbiotechnology.25.61 () [[PubMed][Google Scholar]
80. Nakatsuka T, Mishiba K, Kubota A, Abe Y, Yamamura S, Nakamura N, Tanaka Y, Nishihara M. 2010 Genetic engineering of novel flower colour by suppression of anthocyanin modification genes in gentian. J. Plant Physiol.167, 231–23710.1016/j.jplph.2009.08.007 () [] [[PubMed][Google Scholar]
81. Nakatsuka T, Nishihara M, Mishiba K, Yamamura S. 2006 Heterologous expression of two gentian cytochrome P450 genes can modulate the intensity of flower pigmentation in transgenic tobacco plants. Mol. Breed.17, 91–9910.1007/s11032-005-2520-z () [[PubMed][Google Scholar]