Authorized as of August 12, 2025
We have evaluated information submitted by Norfolk Healthy Produce, Inc. concerning tomato Del/Ros1-N, which bears purple fruit with elevated anthocyanin levels at maturity. We have determined that tomato Del/Ros1-N does not present an altered environmental risk when compared to tomato varieties currently grown in Canada. Tomato Del/Ros1-N is therefore authorized for unconfined release as of August 12, 2025, subject to the provisions outlined in this decision document.
This bulletin was created by the Canadian Food Inspection Agency (CFIA). For further information, contact the Plant Biosafety Office by visiting the contact us page.
On this page
- 1. Brief identification of the modified plant
- 2. Background information
- 3. Description of the novel traits
- 4. Criteria for the environmental assessment
- 5. New information requirements
- 6. Regulatory decision
- 7. Contact us
- 8. References
1. Brief identification of the modified plant
- Designation:
- Tomato Del/Ros1-N (OECD Unique Identifier: NPS-01201-8)
- Applicant:
- Norfolk Healthy Produce, Inc.
- Plant species:
- Tomato (Solanum lycopersicum L.)
- Novel trait:
- Elevated anthocyanin levels and resultant purple colouration throughout the ripe fruit
- Trait introduction method:
- Agrobacterium-mediated transformation
- Intended end use:
- Traditional uses as human food
- Intended area of cultivation:
- Not intended to be grown outside the usual tomato production areas of Canada
2. Background information
Norfolk Healthy Produce, Inc. (hereafter, Norfolk) has developed a tomato that has elevated anthocyanin levels and resultant purple colouration throughout the ripe fruit.
Norfolk provided information on:
- the identity of the tomato Del/Ros1-N
- a detailed description of the introduced genetic elements and proteins encoded by these genetic elements
- information about how the tomato Del/Ros1-N compares to other tomato varieties in terms of its environmental safety
We have reviewed the previously mentioned information, in light of the assessment criteria for determining environmental safety of plant with novel traits (PNTs), as described Directive 94-08 (Dir94-08). We have considered:
- the potential for the tomato Del/Ros1-N to become a weed of agriculture or to be invasive of natural habitats
- the potential for gene flow from the tomato Del/Ros1-N to sexually compatible plants whose hybrid offspring may become more weedy or more invasive
- the potential for the tomato Del/Ros1-N to become a plant pest
- the potential impact of the tomato Del/Ros1-N and its gene products on non-target organisms, including humans
- the potential impact of the tomato Del/Ros1-N on biodiversity
3. Description of the novel traits
3.1. Development method
The tomato Del/Ros1-N was developed through Agrobacterium-mediated transformation of the MicroTom variety using a single plasmid that included a single transfer DNA (T-DNA). The T-DNA contained 3 genes and their regulatory elements:
- the Delila (Del) and Rosea1 (Ros1) genes, both derived from the common garden snapdragon (Antirrhinum majus), to produce 2 major anthocyanins in the tomato ripe fruit
- the nptII gene derived from Escherichia coli, to confer resistance to kanamycin and used as a selectable marker during the transformation process
Tomato leaf discs were cultured on a selective medium containing kanamycin to select transformants. The presence of the transgenes was confirmed by Polymerase Chain Reaction (PCR) and Southern blot analyses. Tomato Del/Ros1-N showed high anthocyanin accumulation in fruit and was selected for further development.
3.2. Purple pigmentation
Introduction of the T-DNA described in 3.1 into the tomato genome results in anthocyanin accumulation, visible as purple colouration in the ripe fruits. The Del and Ros1 genes encode 2 transcription factors derived from the common garden snapdragon (Antirrhinum majus). These transcription factors regulate the pigmentation pattern of anthocyanins in A. majus flowers. When introduced in tomato, both Del and Ros1 genes activate the endogenous tomato anthocyanin biosynthetic pathway. As the Del and Ros1 genes in tomato Del/Ros1-N are both controlled by a promoter specific to ripe fruit, this ultimately results in a purple pigmentation restricted to the ripe tomato fruit.
The Del and Ros1 genes code for the DEL and ROS1 proteins, respectively. The levels of DEL and ROS1 protein expression in Del/Ros1-N fruit were quantified by mass spectrometry. Both DEL and ROS1 proteins were produced at levels under the limit of detection for the assay. The expression of the DEL and ROS1 proteins in tomato Del/Ros1-N was confirmed by the observation of the purple color exhibited by ripe fruit.
The potential allergenicity and toxicity of the DEL and ROS1 proteins were evaluated. These proteins are unlikely to be allergenic, because bioinformatics evaluations of the DEL and ROS1 amino acid sequences do not show any relevant similarities to known allergens.
It was also concluded that the DEL and ROS1 proteins are unlikely to be toxic because:
- both proteins lack a mode of action to suggest that they may be intrinsically toxic
- bioinformatics evaluations of the DEL and ROS1 amino acid sequences confirmed the lack of similarities to known toxins
- the expression levels of DEL and ROS1 proteins in tomato Del/Ros1-N are very low (below the limit of detection)
3.3 Resistance to kanamycin
Tomato Del/Ros1-N contains the neomycin phosphotransferase type II (nptII) gene derived from the bacteria Escherichia coli. The nptII gene encodes the NPTII protein, which phosphorylates kanamycin, rendering it inactive. Resistance to kanamycin was used to select transformed cells during the initial development of tomato Del/Ros1-N and is not a trait of commercial or agronomic interest.
The NPTII protein has been subject to previous safety assessments by us as it is expressed in several authorized PNTs, such as:
The conclusion from these assessments, as well as the information published in scientific literature (EFSA, 2009), have established that the NPTII protein is not a toxic or allergenic protein.
3.4 Stable integration into the plant genome
Junction sequence analyses and genome sequencing demonstrated that tomato Del/Ros1-N contains a single intact copy of the T-DNA with the exact expected sequence. No plasmid backbone sequences, linked or unlinked to the intact insert, were detected in the tomato Del/Ros1-N. The stability of the inserted DNA was demonstrated by the consistent presence of junction sequences across 6 generations and by the stable expression of the phenotype in thousands of cultivated plants. The inheritance pattern of the insert was evaluated by genotypic and phenotypic segregation analyses in an F2 generation of tomato Del/Ros1-N. This analysis showed that the insert segregates according to the Mendelian rules of inheritance for a single genetic locus.
4. Criteria for the environmental assessment
4.1. Potential of the Tomato Del/Ros1-N to become a weed of agriculture or be invasive of natural habitats
As indicated in BIO2025-01: The Biology of Solanum lycopersicum L. (tomato), tomato does not invade unmanaged habitats in Canada. While volunteer tomato plants may emerge in cultivated fields during the season following a tomato crop, they are generally eliminated by frost or standard herbicide applications. There is no evidence that volunteer tomatoes persist as established weeds in Canada. Moreover, there have been no reports of tomato becoming an unmanageable agricultural weed or invasive pest in North America or elsewhere.
Neither the high anthocyanin content in ripe fruit nor the presence of the NPTII selectable maker is expected to alter the reproductive biology or vegetative vigour of the tomato plant. These novel traits are not expected to confer characteristics associated with weediness to the tomato plant, such as increased seed dormancy or enhanced seed dispersal.
Anthocyanins are known to contribute to biotic and abiotic stress response in plants (Li and Ahammed, 2023). While elevation of anthocyanin levels in green tissues has been associated with increase in stress tolerance (Gould, 2004; Ahmadzai et al., 2025), anthocyanin production in tomato Del/Ros1-N is confined to ripe fruit. Thus, tomato Del/Ros1-N is not expected to display increased resistance to stress compared to conventional tomatoes.
We have therefore concluded that tomato Del/Ros1-N has no altered weediness potential in Canada compared to currently grown tomato varieties.
4.2. Potential for gene flow from the Tomato Del/Ros1-N to sexually compatible plants whose hybrid offspring may become more weedy or more invasive
As indicated in BIO2025-01: The Biology of Solanum lycopersicum L. (tomato), there are no species naturally occurring in Canada that are sexually compatible with S. lycopersicum.
The novel traits introduced into tomato Del/Ros1-N are not expected to change tomato reproductive biology.
Based on the previous information, we have concluded that there is no potential for gene transfer from tomato Del/Ros1-N to sexually compatible species in Canada.
4.3. Potential for tomato Del/Ros1-N to become a plant pest
Tomato is not considered to be a plant pest in Canada. The purple colour and high anthocyanin content of ripe fruit, as well as the NPTII selectable marker, are not expected to increase the susceptibility of tomato Del/Ros1-N to pests or pathogens. Therefore, tomato Del/Ros1-N is unlikely to harbour new or increased populations of pathogens or pests compared to conventional tomatoes.
We have therefore concluded that tomato Del/Ros1-N is not expected to display any altered plant pest potential compared to tomato varieties that are currently grown in Canada.
4.4. Potential impact of the tomato Del/Ros1-N on non-target organisms, including humans
We evaluated the potential impacts of the novel traits expressed by tomato Del/Ros1-N, as well as the proteins which confer the novel traits, on non-target organisms.
The production of anthocyanins in ripe fruit and resistance to kanamycin are unlikely to result in different interactions between tomato Del/Ros1-N and organisms interacting with tomatoes, such as:
- pest insects
- pathogens
- pollinators
- soil organisms
It has been determined that the DEL, ROS or NPTII proteins are not toxins or allergens (see 3.2 and 3.3).
Based on the previous information, we have determined that the unconfined release of tomato Del/Ros1-N in Canada will not result in altered impacts on non-target organisms, including humans, when compared to tomato varieties that are currently grown in Canada.
4.5. Potential impact of tomato Del/Ros1-N on biodiversity
Tomato Del/Ros1-N expresses no novel phenotypic characteristics that would extend its range beyond the current geographic range of tomato production in Canada. Tomato Del/Ros1-N is unlikely to cause adverse effects on non-target organisms and is not expected to display increased weediness, invasiveness or plant pest potential compared to tomato varieties grown in Canada. Since tomato has no wild relatives with which it can outcross in Canada, there will be no transfer of the novel traits to other species in unmanaged environments. The agronomic and management practices for tomato Del/Ros1-N are no expected to be different from those currently used for cultivating conventional tomatoes.
We have therefore concluded that the potential impact on biodiversity of tomato Del/Ros1-N is unlikely to be different from that of the tomato varieties that are currently grown in Canada.
5. New information requirements
If at any time, Norfolk becomes aware of any new information regarding risk to the environment or human health that could result from the unconfined environmental release of tomato Del/Ros1-N or lines derived therefrom, Norfolk is required to immediately provide such information to us. On the basis of such new information, we will re-evaluate the potential impact of tomato Del/Ros1-N on the environment and human health and may re-evaluate our decision with respect to the unconfined environmental release authorization of the tomato Del/Ros1-N.
6. Regulatory decision
Environmental release
Based on the review of the data and information submitted by Norfolk and input from other relevant scientific sources, we have concluded that the unconfined environmental release of tomato Del/Ros1-N does not present altered environmental risk when compared to tomato varieties that are currently grown in Canada.
Unconfined release into the environment of tomato Del/Ros1-N is therefore authorized by us as of August 12, 2025.
Lines derived from the authorized line
Any tomato lines derived from tomato Del/Ros1-N may also be released into the environment, provided that:
- no inter-specific crosses are performed
- the intended uses are similar
- it is known based on characterization that these plants do not display any additional novel traits and are substantially equivalent to tomato varieties that are currently grown in Canada, in terms of their potential environmental impact
Other regulatory requirements
is subject to the same phytosanitary import requirements as unmodified tomato varieties. Tomato Del/Ros1-N is required to meet the requirements of other Canadian legislation as applicable, including but not limited to the Food and Drugs Act.
The environmental assessment of PNTs is a critical step in the potential commercialization of these plant types. Other requirements, such as the assessment of novel foods by Health Canada, have been addressed separately from this review. Refer to Health Canada's Decisions on Novel Foods for a description of the food safety assessment of tomato Del/Ros1-N.
7. Contact us
For more information on this decision, contact our Plant Biosafety Office.
8. References
Ahmadzai, A.S., Hu, C., Zhang, C. et al. (2025) Mechanisms of anthocyanin-mediated salt stress alleviation and cellular homeostasis in plants. Plant Growth Regul 105, 655–673.
European Food Safety Authority (2009) Consolidated presentation of the joint Scientific Opinion of the GMO and BIOHAZ Panels on the "Use of Antibiotic Resistance Genes as Marker Genes in Genetically Modified Plants" and the Scientific Opinion of the GMO Panel on "Consequences of the Opinion on the Use of Antibiotic Resistance Genes as Marker Genes in Genetically Modified Plants on Previous EFSA Assessments of Individual GM Plants". EFSA Journal 2009; 7(6):1108, 107 pp.
Gould, K.S. (2004) Nature's Swiss Army Knife: The Diverse Protective Roles of Anthocyanins in Leaves. J Biomed Biotechnol. 2004(5), 314-320.
Li, Z. and Ahammed, G.J. (2023) Plant stress response and adaptation via anthocyanins: A review. Plant Stress, Volume 10