Colour modified petunias | BCH-LMO-SCBD-258884 | Living Modified Organism | Biosafety Clearing-House


Living Modified Organism (LMO)

Decisions on the LMO Risk Assessments  
last updated: 13 Jan 2022
Living Modified Organism identity
The image below identifies the LMO through its unique identifier, trade name and a link to this page of the BCH. Click on it to download a larger image on your computer. For help on how to use it go to the LMO quick-links page.
Colour modified petunias
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The petunia (Petunia hybrida) was modified for red-orange flower coloration through the expression of Zea mays dihydroflavonol 4-reductase, which promotes the synthesis of anthocyanin pigments in the plant. The maize enzyme overcomes the endogenous enzyme's inability to produce pelargonidin derivatives (orange to red pigments) by allowing for the conversion of dihydrokaempferol to leucopelargonidin. Several floral colour variations and varieties exist due to crossing of this modified petunia with other non-modified varieties (Also see 'Additional information' below).

The petunia also expresses Escherichia coli neomycin phosphotransferase II, which allowed for kanamycin or neomycin selection during transformation. 
The term “Recipient organism” refers to an organism (either already modified or non-modified) that was subjected to genetic modification, whereas “Parental organisms” refers to those that were involved in cross breeding or cell fusion.
Characteristics of the modification process
  • Direct DNA transfer
  • Electroporation
  • Heat shock
  • Microinjection
  • Osmotic shock
Some of these genetic elements may be present as fragments or truncated forms. Please see notes below, where applicable.
The modified petunia contains two gene cassettes: Zea mays dihydroflavonol-4-reductase (dfr; also known as A1) and Escherichia coli neomycin phosphotransferase II (nptII).

The dfr coding sequence is under control of a Cauliflower mosaic virus (CaMV) 35S promoter and an Agrobacterium tumefaciens octopine synthase terminator. The allele of the dfr gene that was chosen for the transformation was the allele containing the Cin4-1 element, which does not convey any alter function properties to the DFR protein.

The nptII sequence is under control of an A. tumefaciens nopaline synthase promoter and octopine synthase terminator.

  • Two vector sequences (E. coli beta-lactamase and lacUV5 promoter) are present before the CaMV 35S promoter and between the two gene cassettes, respectively. The beta-lactamase gene is not expected to be active. Similarly, the lacUV5 promoter is not expected to be active in the modified petunia and was active in the bacterial plasmid prior to transformation. This promoter may also function as an efficient terminator for the dfr cassette.
LMO characteristics
  • Ornamental
Detection method(s)
Additional Information
Some unintentional modified varieties are: Big Deal Freaky Fuchsia; Big Deal Salmon Shimmer; Crazytunia® Cherry Cheesecake; Crazytunia® Citrus Twist; Crazytunia® Firecracker; Crazytunia® Maniac Pink; Crazytunia® Star Jubilee; Crazytunia® Swiss Dancer; Hells® Bells Orange; Hells® Fruit Punch; Hells® Glow; Perfectunia® Citrus Wheel; Perfectunia® Mandarin; Perfectunia® Orange; Perfectunia® Orange Morn and Perfectunia® Red impr. Other modified varieties may include: African Sunset; Bonnie Orange; Electric Orange; Raspberry Blast, Salmon Ray and Viva Orange varieties, among others. The flower colour and shade differ between varieties and can be white, red, orange, salmon, pink and pruple. The pattern may also vary, being star-shaped or morn (white/light center). Thus, it is not possible to visually distinguish between modified and non-modified varieties in all cases (other than the presence of orange coloration).

Dihydroflavonol 4-reductase (DFR) is specifically involved in anthocyanin biosynthesis and catalyzes the reduction of the dihydroflavonols dihydroquercetin, dihydromyricetin and dihydrokaempferol to the flavan-3,4-cis diols leucocyanidin, leucodelphinidin and leucopelargonidin, which are the immediate precursors for the respective anthocyanidins cyanidin (red to magenta), delphinidin derivatives (magenta to purple) and pelargonidin (orange to red). Petunia DFR, in contrast to maize A1-DFR, cannot use dihydrokaempferol as a substrate for conversion to leucopelargonidin. Therefore petunias synthesize cyanidin- and delphinidin- derivatives, but not pelargonidinderivatives.
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Record type Field Record(s)