According to findings published in Nature Genetics, the key to the high yield, extra tasty tomatoes is one gene that produces a protein called florigen, which reportedly controls when the plant stops making leaves and starts making flowers and subsequently fruit.
Fruit yield in plants such tomatoes is controlled by a delicate balance between the florigen protein and another protein that delays flowering. The key to improved yield is a mutation in only one copy of the florigen gene causes the hybrid to produce more flowers in less time.
By cross-breeding 33 mutant plants, most of which produced low yield, the US-Israeli team produced hybrids with improved yield – in some cases, the yield increased by 60 per cent. The researchers tapped into a phenomenon called hybrid vigour, or heterosis, by which inter-crossing two varieties of plants produces more vigorous hybrid offspring with higher yields. The phenomenon was first observed by Charles Darwin in 1876.
Furthermore, the researchers observed that the florigen gene is also responsible for boosting sugar content and sweetness of the individual fruits.
“This discovery has tremendous potential to transform both the billion-dollar tomato industry, as well as agricultural practices designed to get the most yield from other flowering crops,” said co-author Dr Zach Lippman from the Cold Spring Harbor Laboratory (CSHL) in New York.
The discovery was patented by Yissum, the technology transfer arm of the Hebrew University, which is seeking potential partners for further development and commercialization.
The new study is reportedly the first example of a single gene consistently causing hybrid vigour. According to the researchers, this study suggests that hybrid mutations might lead the next revolution of improved crops.
Tomatoes have been a fertile ground for researchers in recent years, with scientists from across the globe reporting the development of pink, tangerine, and purple tomatoes, while scientists from the USDA’s Agricultural Research Service reported in The Journal of Experimental Botany (Vol. 59, pp. 2337-2346) that growing regular tomatoes in a mulch of hairy vetch activates the same flavour and nutrition-boosting genes and metabolic pathways as in transgenic tomatoes.
Hairy vetch (Vicia villosa Roth) is a hardy legume native to Europe and Asia that is often used for soil improvement purposes. In the ARS study conducted by Italian and American scientists it was used as a mulch or protective cover over tomato plants.
Source: Nature Genetics
Published online ahead of print, doi: 10.1038/ng.550
“The flowering gene SINGLE FLOWER TRUSS drives heterosis for yield in tomato”
Authors: U. Krieger, Z.B. Lippman, D. Zamir