They’re typically a summer fruit – but strawberries could soon be enjoyed out of season, thanks to a new gene edited variety set to be sold in British supermarkets.
Scientists have tweaked the DNA of the strawberry plant, turning off particular genes to allow it to produce fruit for a longer period of time.
The strawberries, created by US company Simplot, have reached the final approval stage before being legally allowed to be sold to members of the public.
A notice, published by the Department for Environment, Food & Rural Affairs (Defra), reads: ‘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, which has an altered flowering pattern with a longer harvest season.’
It adds that the DNA change does not alter the composition or nutrition of the fruit.
In total, eight different gene–edited strawberry varieties – all of which have a longer growing season – have been submitted for review.
And if approved by the Food Standards Agency, they could soon appear in your local shop.
For the new strawberries, scientists used ‘molecular scissors’ called CRISPR/Cas9 to precisely cut the Tfl1 gene so it no longer functions properly (stock image)
Increasing the availability of British strawberries would reduce reliance on imports from Spain, Morocco and Egypt during the cooler winter months.
One UK company, based near Chichester, has already managed to extend their strawberry growing season to a full 12 months.
However, this achievement is due to innovative LED technology and a combined heat and power plant, which recreate optimal spring conditions indoors during colder months.
For the new strawberries, scientists used ‘molecular scissors’ called CRISPR/Cas9 to precisely cut the Tfl1 gene so it no longer functions properly.
This changes the plant’s flowering behaviour, making it remontant – meaning it can flower and produce fruit repeatedly rather than producing one main crop.
While the Defra notice does not explicitly state how long the growing season would be for the gene edited fruit, it is thought it could allow for year–round growing.
A key feature of the new fruit is that its genetic changes are ones that could have occurred – over many decades – through traditional breeding methods.
Alongside strawberries, gene–edited tomatoes, developed by the John Innes Centre in Norfolk, are up for review.
Alongside strawberries, gene–edited tomatoes, developed by the John Innes Institute in Norfolk, are up for review. Pictured: A vitamin D tomato (left) and a wild type tomato (right)
These ‘sunshine’ tomatoes have as much vitamin D as two eggs or 28g tuna, scientists say.
Experts were able to turn off a gene that makes an enzyme convert vitamin D3 into cholesterol so that it stays in the leaves and fruit.
This fortified crop could help in the battle against ‘endemic vitamin D deficiency, especially in autumn and winter seasons’, Defra said.
Professor Cathie Martin, who leads the lab where the tomatoes are developed, said all new plant varieties go through strict testing – and these crops will be held to the same standards.
‘I am passionate about science supporting public health, and with vitamin D deficiency a widespread problem, our biofortified tomato could one day be a low–cost, simple, plant–based solution that can improve diets across the world,’ she added.
‘This is an important step in getting the tomato approved to go to market in England.’
Once the products reach shelves, they will not require a label identifying them as being gene–edited.
Gene editing involves making small, specific changes to the existing DNA of a product, or removing a section of DNA. The process differs from genetic modification, which adds new genes to a crop.
Scientists have also produced disease–resistant potatoes, high–fat barley to feed cows and wheat with lower levels of a cancer–linked chemical, all of which have also received a marketing notice from Defra.
Earlier this year, scientists announced they had bred cows with ‘elite genetics’ that could see tastier steaks, burgers and mince on supermarket shelves in the UK in just three years.
Experts in the US have come up with a way to make sperm from superior bulls more available to breeders.
Their project, called ‘Surrogate Sires’, involves genetically editing regular bulls to make them sterile, meaning they produce none of their own sperm.
These animals then receive an injection of stem cells taken from the testicles of another bull with ‘first–class genetics’.
When these ‘surrogate’ bulls go on to breed, they pass on the ‘top grade’ genes from the other bull – meaning their offspring will contain superior traits that make their meat taste better.
As a result the most desirable steaks – from the likes of Wagyu and Black Angus cows – could soon become more widely available.
WHAT IS CRISPR-CAS9?
Crispr-Cas9 is a tool for making precise edits in DNA, discovered in bacteria.
The acronym stands for ‘Clustered Regularly Inter-Spaced Palindromic Repeats’.
The technique involves a DNA cutting enzyme and a small tag which tells the enzyme where to cut.
The CRISPR/Cas9 technique uses tags which identify the location of the mutation, and an enzyme, which acts as tiny scissors, to cut DNA in a precise place, allowing small portions of a gene to be removed
By editing this tag, scientists are able to target the enzyme to specific regions of DNA and make precise cuts, wherever they like.
It has been used to ‘silence’ genes – effectively switching them off.
When cellular machinery repairs the DNA break, it removes a small snip of DNA.
In this way, researchers can precisely turn off specific genes in the genome.
The approach has been used previously to edit the HBB gene responsible for a condition called β-thalassaemia.
