Scientists have caused tomatoes to produce large amounts of nutrients.
The researchers, from the John Innes Center in the UK, have discovered a way to produce industrial quantities of two useful natural compounds efficiently by growing them in tomatoes: the phenylpropanoids resveratrol and genistein.
Resveratrol has been reported to extend lifespan in animal studies and is found in red grape skins and wine. It has been linked to decreased risk of coronary artery disease and cancer prevention. Previous studies have also found that it protected against lipid peroxidation in cell membranes and DNA damage caused by reactive oxygen species, which contribute to oxidative stress.
Genistein is found in soybeans. Tests have shown that it may help prevent steroid-hormone related cancers, particularly breast cancer, and that it could help to enhance the body's immune responses.
Benefits of 50 bottles of red wine in one tomato
Dr. Yang Zhang and colleagues have found a way to make one tomato produce the same quantity of resveratrol as exists in 50 bottles of red wine, or the same amount of genistein found in 2.5 kg of tofu.
- The tomato is of the deadly nightshade plant family
- 200 years ago, tomatoes were thought to be poisonous in the US
- Tomatoes contain nutrients that can help prevent cancers, high blood pressure and depression.
They have been studying the effect of a protein called AtMYB12, found in Arabidopsis thaliana - a plant that grows in most UK gardens and is used as a model plant in scientific investigation.
The protein AtMYB12 activates a broad set of genes involved in metabolic pathways responsible for producing natural compounds that are useful for the plant.
AtMYB12 is able to increase or reduce the production of natural compounds, depending on how much of the protein is present.
When the protein was introduced into a tomato plant, it had two effects.
Firstly, it increased the capacity of the plant to produce natural compounds by activating phenylpropanoid production. Secondly, it influenced the amount of energy and carbon the plant dedicated to producing these natural compounds.
Added protein and genes produce 80 g of new compound
In response to the protein, tomato plants began to create more phenylpropanoids and flavanoids devote more energy to the process.
When scientists introduced both AtMYB12 and genes from plants encoding enzymes specific for making resveratrol in grape and genistein in legumes, the tomatoes produced up to 80 mg of novel compound per gram of dry weight, indicating that large-scale production is possible.
Tomatoes are a high yielding crop. They produce up to 500 tonnes per hectare in countries delivering the highest yields and require relatively little input.
Therefore, production of valuable compounds like resveratrol or genistein in tomatoes could be a more economical way of producing them than relying on artificial synthesis in a lab or extracting them in tiny quantities from traditional plant sources, such as grapes and soybeans.
The tomatoes can be harvested and juiced, and the valuable compounds can be extracted from the juice. The tomatoes themselves could potentially become the source of increased nutritional or medicinal benefit.
Dr. Zhang says:
"Medicinal plants with high value are often difficult to grow and manage, and need very long cultivation times to produce the desired compounds.
Our research provides a fantastic platform to quickly produce these valuable medicinal compounds in tomatoes. [...] We believe our design idea could also be applied to other compounds such as terpenoids and alkaloids, which are the major groups of medicinal compounds from plants."
Prof. Cathie Martin, in whose lab the work was carried out, believes the study provides a general tool for producing valuable phenylpropanoid compounds on an industrial scale in plants. She adds that it could be used to create other products derived from aromatic amino acids.
She foresees that it will be of interest to different research areas including plants, plant/microbe engineering, medicinal plant natural products, as well as diet and health.Medical News Today recently reported that compounds found in tomatoes could help to block age-related muscle wasting.
Written by Yvette Brazier