Vitamin D deficiency is becoming more widespread as vegan and vegetarian diets become more popular. Jie Li, a postdoctoral researcher at Norwich Research Park’s John Innes Centre, discusses how she is using gene editing to fortify tomatoes and play ‘ketchup’ on this worldwide public health concern.
Every month, those who work at the cutting-edge heart of Norwich Research Park tell us how their work is influencing the world we live in. Read about them here.
What is the scope of investigation?
My research employs biotechnologies such as gene editing to supplement meals with important vitamins and phytonutrients. Gene editing is similar to using a pair of molecular tweezers. The approach might be used to remove a small portion of a gene and modify the pathway to improve plant nutrition. My research focuses on vitamin D3 biofortification of tomatoes.
Biofortification is an effective technique to alleviate vitamin deficiencies that is not limited to tomatoes. We believe that similar possibilities exist in closely related plants such as pepper, aubergine, and potato.
I am also a board member of the Wellcome Trust-funded EDESIA Ph.D. program, which aims to develop major aspects of plant-based nutrition and health — from crop to clinic.
Vitamin D deficiency affects approximately one billion people globally and is connected with a deleterious influence on immunological function and inflammation. It has also been related to an increased risk of cancer, dementia, and depression. Vitamin D deficiency has even been associated to increased severity of Covid-19 infection in studies.
The typical dietary consumption of vitamin D in the United Kingdom is about three micrograms per day, although the recommended daily dose is ten micrograms. This nutritional gap could be filled by two medium-sized biofortified tomatoes. Engineering vitamin D in plants is an unique and cost-effective technique to address the deficiency, with the added benefit of producing vegan-friendly supplements from the vitamin D-enriched plants’ leaf extracts.
Why was research centered on tomatoes?
Tomatoes naturally contain the vitamin D3 building block known as provitamin D3 or 7-dehydrocholesterol (7-DHC). However, provitamin D3 is not generally found in mature tomato fruits. Gene editing allows us to introduce or improve certain features far more efficiently, precisely, and quickly than traditional breeding procedures.
I genetically modified tomatoes to produce provitamin D3 by inhibiting an enzyme called 7-dehydrocholesterol reductase 2. (Sl7-DR2). In tomatoes, inhibiting this enzyme had no effect on growth, development, or yield; the accumulated provitamin D3 can then be converted to vitamin D3 via UVB irradiation. After UVB treatment, one tomato contains the same amount of vitamin D3 as two medium-sized eggs or 28 grammes of tuna.
