Research and analysis

Precision bred organism marketing notice (reference: PBM/26/FRAN/008)

Published 21 August 2026

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

Simplot Company, 5369 W Irving St. Boise, Idaho, 83706, United States 

2. General description of the precision bred plant

a) Genus and species

Fragaria × ananassa, Strawberry.  

The S4A-210 precision bred line is an octoploid strawberry variety. 

b) Intended alterations to characteristics of the plant

The genetic alteration was designed to knock out the Terminal Flower 1 gene (Tfl1) in strawberry. Knock out of one or more alleles of Tfl1 resulted in a remontant strawberry, S4A-210, which has an altered flowering pattern with a longer harvest season compared to the parent variety. Tfl1 does not play a role in composition, nutrition, or allergenicity in strawberries and has a non-toxic mode of action.

Remontancy exists in many wild strawberry varieties and in some commercial varieties. The remontant trait enables growers to harvest fruit for a longer period from strawberry fields. While breeding could have been used to transfer remontancy, using gene editing enabled us to edit the remontancy trait in a commercial strawberry variety without losing the identity and desirable attributes of this variety.

c) Types of genetic changes introduced to cause these alterations

The genetic alteration knocked out one or more alleles of the Tfl1 gene. Knock out of Tfl1 resulted in a remontant strawberry, which has an altered flowering pattern with a longer harvest season compared to the parent variety.

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

Agrobacterium transformation was used to introduce DNA into strawberry cells using a method optimized for transient expression. This DNA encoded Cas9 and a guide RNA (gRNA) designed specifically to target Tfl1. Transient expression resulted in breaks in the plant genomic DNA at the target site and these were repaired by the plant’s endogenous repair mechanism. Repair resulted in sequence errors at some sites which stopped the expression of Tfl1 at these repaired alleles. Decreased expression of the Tfl1 product resulted in remontant strawberry plants with a longer harvest season.

3. Intended use of the precision bred plant

The intended use of the precision bred strawberry is the same as that of conventionally bred strawberries. The precision bred strawberries outlined in this notification are intended for commercial cultivation in England and consumption as fresh fruit or in processed food products.  

Simplot plans to run line selection trials in England in 2026 with these eight strawberry lines. The trials will include value chain consultation and taste testing to select the best lines for production in England and marketing of fresh fruit in England, Wales, and Scotland. Commercial production and marketing of the lines will follow once line selection is completed and the lines have been registered for production in England. 

4. Intended genetic changes made

(a) the details of genetic changes made;

Strawberry (Fragaria x ananassa) is an octoploid species composed of four diploid sub genomes (A, B, C, and D) ​(Folta and Barbey, 2019)​. Tfl1 is present in all sub genomes with sub genome D containing only one copy of Tfl1 (present in D1 and absent on D2), resulting in seven copies of Tfl1 in the strawberry genome.  

The precision bred strawberry lines were developed using CRISPR/Cas9 gene editing to knock out one or more alleles of Tfl1. The plasmid encoded Cas9 and a gRNA that was designed specifically to target Tfl1. Agrobacterium tumefaciens transformation was used to deliver the gene editing components into strawberry cells and transiently express the DNA. Knock outs in edited Tfl1 alleles enabled the strawberry to produce fruit over an extended harvest season compared to the parent variety, which is referred to as remontancy. The remontancy trait could be bred into strawberry varieties but the genetic complexity of octoploid varieties makes it difficult to reestablish the traits that make non-remontant strawberry varieties popular with growers and consumers. 

The Cas9 nuclease is bound to the trans-acting CRISPR RNA (tracrRNA) region of the gRNA. The CRISPR RNA (crRNA) region of the gRNA directs the nuclease to regions of the plant’s genome containing a PAM recognition site (‘NGG’) immediately flanked by sequence identical to or highly similar to the crRNA sequence. Only sequences meeting both criteria are cleaved by Cas9, resulting in double-stranded breaks. The cell’s endogenous DNA repair mechanism repairs the break via non-homologous end-joining (NHEJ), a process that can introduce small insertions, deletions, or substitutions at, or around, the target cut site. Such edits may disrupt the coding sequence of the target gene, potentially introducing premature stop codons resulting in truncated, loss-of-function mutations. Details regarding the number and size of insertions, deletions, and/or substitutions in the S4A-210 strawberry line can be found in Table 1.  

Reference: Folta, K.M., and Barbey, C.R. (2019). The Strawberry Genome: A Complicated Past and Promising Future. Horticulture Research 6. 

(b) the location of genetic changes;

Table 1. Summary of Edits in the Precision Bred S4A-210 Strawberry Line 

Precision bred S4A line	Number of edited alleles1	Summary of edits2	Phenotype
S4A-210	7	1 to 4 bp deletions	15 bp insertion	1 to 3 bp substitutions	Remontant

1 Strawberry (Fragaria x ananassa) is octoploid, composed of four diploid sub genomes (A, B, C, and D). There are 7 Tfl1 alleles in the parent strawberry genome. 

2 In all cases, inserted DNA was genomic strawberry DNA. 

(c) the stability of genetic changes;

Commercial strawberries are vegetatively propagated; therefore, the progeny plants do not undergo meiotic recombination and are considered genetically and phenotypically stable. Nevertheless, the stability of the edits in the precision bred strawberry lines was confirmed by PCR and nanopore sequencing over three rounds of consecutive vegetative propagation demonstrating stability of the targeted edits. 

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;

No transgenic DNA remained in the final precision bred strawberry lines. The pSIM2797 was introduced using Agrobacterium tumefaciens transformation and was transiently expressed but not integrated into the plant genome. Molecular analysis confirmed the absence of plasmid-derived sequences in the eight precision bred strawberry lines.  

In some cases, small base pair insertions were observed at the target site, consistent with repair using the plant’s NHEJ mechanism. Bioinformatic analysis of these insertions confirmed that all inserted sequences originated from the strawberry genome itself, and not from the plasmid. 

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

Knock out of one or more alleles of TFL1 resulted in a remontant strawberry, which has an altered flowering pattern with a longer harvest season compared to the parent variety. Tfl1 does not play a role in composition, nutrition, or allergenicity in strawberries and has a non-toxic mode of action. 

5. Unintended genetic changes made

(a) the details of genetic changes made;

Analysis indicated that no unintended genetic changes were introduced into the precision bred line as a result of the gene editing.

(b) the location of genetic changes;

Analysis indicated that no unintended genetic changes were introduced into the precision bred line as a result of the gene editing.

(c) the stability of genetic changes;

Analysis indicated that no unintended genetic changes were introduced into the precision bred line as a result of the gene editing.

6. How the intended genetic changes were introduced

(a) which techniques of modern biotechnology were used;

The precision bred strawberry line was developed using CRISPR/Cas9 gene editing to knock out one or more alleles of Tfl1. Knock outs in Tfl1 enabled the S4A strawberry line to produce fruit over an extended harvest season compared to the parent variety, which is referred to as remontancy.  

Agrobacterium tumefaciens transformation was used to deliver the gene editing components into strawberry cells and transiently express the DNA. This DNA encoded Cas9 and a gRNA designed specifically to target Tfl1. 

The transformation plasmid contained elements to facilitate the identification and elimination of plants containing plasmid DNA. An antibiotic resistance marker was used to screen and discard plants with plasmid DNA, and two screenable markers were included to identify and discard plants retaining plasmid backbone sequences. 

Strawberry lines that met the criteria for precision breeding were field tested to assess the remontancy trait.

(b) information about any transgenic intermediates used;

No transgenic intermediates were used in the production of S4A-210.

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.

To confirm that the final precision bred strawberry line contained only genetic changes that could have occurred through traditional breeding methods, absence of plasmid integration was evaluated by PCR. Sixteen PCR assays were designed to identify pSIM2797 plasmid integration. The PCR analysis confirmed the absence of pSIM2797 DNA in the precision bred strawberry lines.  

The absence of plasmid sequences was confirmed a second time by next generation sequencing for the commercial lines. This confirmation will be completed for the lines commercialized in England. 

8. Other precision bred plants covered by this marketing notice

(a) Total number of precision bred plants being notified 

A total of eight precision bred strawberry lines are included in this marketing notice (Table 2). 

Table 2. Precision Bred Strawberry Lines Included in this Marketing Notice. 

DEFRA Designation	Precision Bred Strawberry Line
Precision Bred Plant 2 (PBM/26/FRAN/008-2)	S4A-115
Precision Bred Plant 1 (PBM/26/FRAN/008-1)	S4A-210
Precision Bred Plant 3 (PBM/26/FRAN/008-3)	S4A-293
Precision Bred Plant 4 (PBM/26/FRAN/008-4)	S4A-334
Precision Bred Plant 5 (PBM/26/FRAN/008-5)	S4A-336
Precision Bred Plant 6 (PBM/26/FRAN/008-6)	S4A-444
Precision Bred Plant 7 (PBM/26/FRAN/008-7)	S4A-448
Precision Bred Plant 8 (PBM/26/FRAN/008-8)	S4A-480

 (b) Confirmation of precision breeding criteria

All eight precision bred strawberry lines are Fragaria x ananassa and were developed at the same time with the same intended gene edit: the knockout of one or more alleles of the Tfl1 gene, which confers a remontant phenotype. All eight precision bred strawberry lines are remontant and meet the criteria set out in Regulation 5(4) for grouped notification, having been developed and assessed using identical methods, Table 3. 

All eight precision bred strawberry lines were developed using identical transformation and gene editing protocols, including Agrobacterium tumefaciens transformation with pSIM2797, which was transiently expressed in these lines and encoded Cas9 and a guide RNA targeting Tfl1. All precision bred strawberry lines were screened initially in a similar manner for plasmid DNA integration using antibiotic resistance and visual markers.  

To confirm that the final precision bred strawberry lines contain only genetic changes that could have occurred through traditional breeding methods, each precision bred strawberry line underwent the same molecular analysis that included PCR and genomic sequencing. This confirmed the absence of integrated plasmid DNA in the plant genomes. 

Table 3. Assessment Summary of Eight Precision Bred Strawberry Lines 

Precision Bred Strawberry Line	Analysis of Edits	Presence of foreign DNA	Stable	Unintended Changes
S4A-115	Yes	No	Yes	No
S4A-210	Yes	No	Yes	No
S4A-293	Yes	No	Yes	No
S4A-334	Yes	No	Yes	No
S4A-336	Yes	No	Yes	No
S4A-444	Yes	No	Yes	No
S4A-448	Yes	No	Yes	No
S4A-480	Yes	No	Yes	No

(c) Variations in intended genetic changes introduced

A summary of the variation regarding the number and size of insertions, deletions, and/or substitutions introduced in each precision bred organism is provided in Table 4.

Table 4. Summary of Edits in Eight S4A Strawberry PBO Lines 

Precision Bred S4A Line	Number of Edited Alleles1	Summary of Edits2	Phenotype
S4A-115	6	1 to 31 bp deletions	15 bp insertion	2 bp substitution	Not edited	Remontant
S4A-210	7	1 to 4 bp deletions	15 bp insertion	1 to 3 bp substitutions	Remontant
S4A-293	3	16 to 25 bp deletions	Not edited	Remontant
S4A-334	5	1 to 48 bp deletions	Not edited	Remontant
S4A-336	6	1 to 22 bp deletions	16 bp insertion	Not edited	Remontant
S4A-444	7	1 to 14 bp deletions	2 bp substitution	Remontant
S4A-448	7	1 to 5 bp deletions	1 bp insertion	1 bp substitution	Remontant
S4A-480	5	1 to 51 bp deletions	Not edited	Remontant

1 Strawberry (Fragaria x ananassa) is octoploid, composed of four diploid sub genomes (A, B, C, and D).  
There are 7 Tfl1 alleles in the parent strawberry genome. 

2 In all cases, inserted DNA was genomic strawberry DNA. 

The absence of non-target editing was examined in all the precision bred strawberry lines using nanopore sequencing. The results showed that the sequence of one potential non-target site remained identical to the parental genome and was not edited. 

The stability of the gene edits was confirmed through PCR and nanopore sequencing over three consecutive rounds of vegetative propagation, demonstrating that the intended genetic changes were stable and maintained across propagations. 

(d) Variations in unintended genetic changes introduced

No unintended genetic changes attributable to modern biotechnology were detected in any of the eight precision bred strawberry lines. Observed variation in edits is consistent with natural polymorphism and does not affect the precision bred status of the strawberry lines.