Scientists discover how tomato ripening can be slowed down and sped up
With the global population continuing to increase and arable land continuing to shrink, there is an urgent need to improve the efficiency of food production, and a new technology developed at the University of Oxford could offer a helping hand. Scientists there have come up with a way to control the speed at which tomatoes ripen by modifying a specific gene, which could not only help reduce wastage and boost yields of these fleshy fruits, but possibly other crop varieties, too.
The work was carried out at the university's Department of Plant Sciences, where researchers where investigating the underlying mechanisms behind the fruit ripening process. Tiny units called plastids that are packed with proteins are known to play a central role in this and give fruits like tomatoes their bright colors, but exactly how they do this hasn't been so well understood.
So the scientists investigated further by turning their attention to a previously discovered regulatory pathway called CHLORAD (short for Chloroplast Associated Protein Degradation), which enables plastids to import proteins they need from elsewhere in the plant and remove proteins they don't. This allows the plastids to not just ripen the fruit, but perform various functions that are critical to the plant's success, from the seed's germination to the production of fruit.
By studying this in greater detail, the scientists were able to pinpoint a single protein in the plastids that plays a regulatory role in the CHLORAD system. The scientists were able to show how knocking out the gene responsible for this SP1 protein delayed the ripening of tomatoes, while heightened its expression resulted in accelerated ripening.
The scientists believe this discovery lays the groundwork for technologies that manipulate the CHLORAD system to improve the efficiency of crop production. For example, it might be used to improve the output of potato plants, wheat that stays greener for longer to produce more grain could be created, or tomatoes could be made to ripen quickly or stay fresher for longer.
"The regulatory properties of SP1 revealed in our study show that it has real potential as a technology for crop improvement," says study author Professor Paul Jarvis. "For example, it could be used to develop early or late fruiting varieties of fleshy fruits, or to improve the transportability or shelf-life of fruit by delaying ripening without compromising the quality of the ripe fruit. It’s fascinating that the amount of a single protein in these tiny subcellular structures called plastids can have such far-reaching consequences for fruit ripening in tomato."
The research was published in the journal Nature Plants.
Source: University of Oxford