Research and analysis

Precision bred organism marketing notice (reference: PBM/25/SOTU/002)

Published 3 July 2026

Applies to England

Information provided to the Secretary of State alongside a notice of intention to market a precision bred plant under schedule 2 of the Genetic Technology (Precision Breeding) Regulations 2025.

1. Name and address of the person with overall responsibility for marketing the precision bred plant

BioPotatoes, Centrum, Norwich Research Park, Colney Lane, Norwich NR4 7UG

2. General description of the precision bred plant

a) Genus and species

Solanum tuberosum

b) Intended alterations to characteristics of the plant

Solanum tuberosum variety Maris Piper was transformed with a stack of six single-copy cisgenes to achieve resistance to late blight (three cisgenes), resistance to potato virus Y (PVY) and resistance to potato leafroll virus (PLRV) (one cisgene each). The sixth cisgene is an allele of potato Acetolactate synthase that enables selection in vitro only.

c) Types of genetic changes introduced to cause these alterations

The inserted cisgenes encode receptor proteins that detect pathogen ligands and activate potato defences against these pathogens.

d) Techniques of modern biotechnology used to make these genetic changes

Agrobacterium-mediated transformation.

3. Intended use of the precision bred plant

For cultivation in England for use as food and feed.

4. Intended genetic changes made

(a) the details of genetic changes made;

Insertion of a T-DNA sequence comprising six cisgenes connected with short linker sequences; three cisgenes for resistance to late blight, on each for resistance to PVY and PLRV, and one as a selection market in vitro. T-DNA also contains short linker and border sequences at the beginning and end of the T-DNA.

(b) the location of genetic changes;

Non-targeted insertion.

(c) the stability of genetic changes;

The precision bred plant material reported here is exclusively vegetatively propagated. Vegetative propagation (VP) is commonly used to preserve the quality of planting material through multiple years by avoiding meiosis, segregation, and homologous recombination. VP has been also repeatedly proven to maintain the stability of introduced DNA sequences and prevent loss of trait efficacy in potato (see Pence and others, 2024). The cisgenes used here have been stably maintained in potato since the first lines were generated in 2017. Rpi-vnt1 and Rpi amr3 were also independently introduced and stably maintained in several commercial biotech varieties marketed in the US.  

 d) when a genetic change involves the insertion of any genetic material, a description of all the genetic elements inserted and the organism from which they originated;

Cisgenes 1-3: Rpi-vnt1.1 from Solanum venturii, Rpi-amr3 and Rpi-amr1 from Solanum americanum – resistance genes of the CNL class which confer resistance to a large range of isolates of the late blight pathogen Phytophthora infestans; expressed under control of their endogenous 5’ and 3’ regulatory sequences. GenBank: FJ423044.1

Cisgene 4: Rysto from Solanum stoloniferum – resistance gene of the TNL class which confers resistance to potato virus Y; expressed under control of its endogenous regulatory sequences. GenBank:MN393235.1

Cisgene 5: Rladg from Solanum tuberosum subsp. andigena – resistance gene of the TNL class which confers resistance to potato leafroll virus; expressed under control of it endogenous regulatory sequences. (Heal, R. P. J. (2024). Genetic and molecular analysis of Solanum disease resistance genes. Doctoral thesis, University of East Anglia

Cisgene 6: Acetolactate synthase (ALS) gene from Solanum tuberosum – changed at 2 positions to create an allele that is resistant to inhibition by chlorsulfuron; expressed under control of its endogenous regulatory sequences. For in vitro selection only, not intended as a trait. Gene ID: 102594064

Analysis of the linker and border sequences revealed sequence-identical regions in several Solanum species within the potato gene pool (S. tuberosum, S. stenotonum, S. verrucosum).

e) the purpose of the genetic changes described above in sub-paragraphs (a) to (d), including how they alter the characteristics of the precision bred plant

The cisgenes were added to provide resistance to late blight, PVY and PLRV. These cisgenes encode plant receptors that perceive pathogen-derived ligands (such as Phytophthora infestans-secreted effectors, PVY coat protein and PLRV P1 protease). The recognition of pathogen ligands by the receptors activates innate potato defences against these pathogens, leading to resistance. 

The complete late blight resistance provided by this triple Rpi- gene stack is the kind of trait we need to meet our commitments to reducing the environmental impact of agriculture and to bring us closer to net zero by reducing CO2 emissions from fungicide applications and to improve food security. Furthermore, the virus resistance provided by the Rysto and Rladg genes will greatly reduce the costs and losses involved in seed potato cultivation and reduce the need for insecticide applications to restrict viral transmission.

5. Unintended genetic changes made

(a) the details of genetic changes made;

Not present – no unintended genetic changes present.

(b) the location of genetic changes;

Not applicable – no unintended genetic changes present.

(c) the stability of genetic changes;

Not applicable – no unintended genetic changes present.

6. How the intended genetic changes were introduced

(a) which techniques of modern biotechnology were used;

Agrobacterium-mediate transformation with a T-DNA assesmbled using a Golden Gate binary vector backbone that had been optimized to reduce the frequency of backbone insertion events using a counterselection outside the left border.

(b) information about any transgenic intermediates used;

Not applicable.

7. Analysis and procedures used

(a) description of the analysis and procedures used to confirm the plant only contains genetic sequences that could arise by traditional processes.

The cisgenes and the other sequences comprising the inserted T-DNA all originate from genus Solanum and either have already been bred into some potato varieties or could have been plausibly bred in. Out of all source species, Solanum americanum might require more background information to ascertain its eligibility. 

S. americanum berries and leaves are often part of the human diet, particularly in Africa and China, but also in India and Indonesia (Särkinen and others, 2018). Viable and vigorous somatic hybrids of diploid S. americanum with tetraploid Desiree potato have been reported (Horsman and others, 1997). S. americanum has a hexaploid derivative, Solanum nigrum, which naturally arose through polyploidy; these two species can be crossed, and fertile F1 plants obtained (Lee and others, 2023). Somatic hybrids between S. nigrum and diploid or tetraploid potato have been reported (among others, Binding and others, 1982; Colon and others, 1992; Horsman and others, 1997; Szczerbakowa and others, 2003). Moreover, first and second backcrosses of S. nigrum somatic hybrids with S. tuberosum to tetraploid potato were successfully achieved (Horsman and others, 1999); the same report also demonstrates effective incorporation of the resistance-conferring genetic material into the recombining genetic pool of the BC2 progeny and genetic segregation of that resistance. Furthermore, successful somatic fusion experiments were performed between the above mentioned BC1 and BC2 and several potato cultivars (Horsman and others, 2001). As Rpi-amr1 and Rpi-amr3 are also found in S. nigrum, we therefore believe this provides strong evidence for potential introgression of resistance traits from S. nigrum into S. tuberosum by back-crossing. 

We would reiterate that Rpi-amr homologs (~71% identity for Rpi-amr1, ~75% identity for Rpi-amr3) are already present in potato and that using AlphaFold, they are predicted to adopt essentially the same protein structure and can therefore be considered alleles.

Furthermore, a United States Environmental Protection Agency (US EPA) approval for S. tuberosum plants carrying one of our two genes from S. americanum, Rpi-amr3 has been granted. In the submission it was said:

“the source plant of AMR3 (Rpi-amr3) is Solanum americanum, a species in the Morelloid clade[1] (commonly referred to as the black nightshades) of the Solanum L. genus. Species within the Morelloid clade are capable of forming interspecific hybrids, although with varying degrees of hybrid fertility (Baylis, 1958; D’Arcy, 1974; Edmonds and Chweya, 1997). For example, S. americanum will hybridize with S. nigrum (Ganapathi and Rao, 1986; Venkateswarlu and Rao, 1972). Species from the Morelloid clade have been successfully crossed with S. tuberosum using modern breeding techniques. […] The results of naturally occurring hybridizations and embryo capture indicate that genetic material from S. americanum could be introgressed to S. tuberosum using conventional breeding techniques, including wide crosses, ploidy manipulations, 2n gametes, and embryo capture (Jansky, 2006).” Thus, Rpi-amr3 is already part of the human diet in the US.

The presence of the cisgenes was confirmed by diagnostic PCRs across the unique junctions between genes in the T-DNA. The copy number was established by TaqMan Copy Number Assay by https://www.attodna.com/. The absence of backbone sequences was verified by 10x Illumina whole genome short read sequencing followed by kmer analysis, and by PCR. 

8. Other precision bred plants covered by this marketing notice

(a) Total number of precision bred plants being notified 

Two independent lines of potato var. Maris Piper carrying the above set of cisgenes (Plant 1 and 2).  

(b) Confirmation of precision breeding criteria

Both plants meet the criteria

(c) Variations in intended genetic changes introduced

No variation between Plant 1 and Plant 2 except with regard to T-DNA insertion location. 

(d) Variations in unintended genetic changes introduced

No unintended changes present in Plant 1 or Plant 2. The T-DNA insertion is an intended change.