Supersweet protein thaumatin II in fruit and berry plants

Thaumatin II protein from the West African plant Thaumatococcus daniellii Benth. has unique properties – it is 3000 times sweeter than sucrose and is extremely resistant to heating in an acidic environment. It has been comprehensively studied and approved for use as a food additive E957. Thaumatin II belongs to the family 5 pathogenesis-related proteins and is involved in plant defense against fungal pathogens. The complex properties of thaumatin make it a promising object for use in breeding to improve the fruit and berry plants resistance to fungal pathogens, and to improve the taste of their fruits. A topical task is also to obtain plants producing recombinant thaumatin II for the needs of the food industry. The review examines the structure and properties of thaumatin II, the principles of its sweet taste formation, successes in obtaining plants transformed with the thaumatin II gene, and the results of their study. The prospects for using thaumatin II in further studies to improve the agronomic and consumer characteristics of agricultural plants, including fruits and berries, are discussed. The review is addressed to a wide range of readers, including researchers and breeders interested in modern molecular biological approaches for use in the selection of fruit and berry plants.