Scientists at the University of Oxford have figured out how to alter tomatoes’ color and ripening speed by modifying a specific gene. The discovery could help improve the transportability of fruit, reduce wastage, boost tomato yields, and possibly other crop varieties.
The novel work was carried out at the university’s Department of Plant Sciences, where researchers examined the fundamental mechanisms behind the fruit ripening process. Tiny “organelles” in the fruit cells called plastids that contain proteins are responsible for giving fruits like tomatoes their bright colors. However, little was known about how exactly plastids participate in the ripening process.
The Oxford team investigated further by turning their attention to a regulatory pathway called CHLORAD (Chloroplast Associated Protein Degradation), initially discovered by the group in 2019. CHLORAD enables plastids to import proteins they need from elsewhere in the plant and eliminate proteins they don’t need, allowing the plastids to ripen the fruit and perform several critical functions to ensure the plant’s success, from the seed’s germination to fruit production.
The researchers identified a single protein in the plastids called SP1 that plays a regulatory role in the CHLORAD system. The Oxford team demonstrated how knocking out the gene responsible for this SP1 protein slowed the ripening of tomatoes while intensifying its expression resulting in accelerated ripening.
These findings lay the groundwork for technologies that control the CHLORAD system to improve crop production efficiency. For example, it could create wheat that stays greener for longer – producing more grain, enhancing the yield of potato plants, or altering tomatoes to stay fresher for longer or ripen quickly.
Professor Paul Jarvis, the study’s author, explained:
“The regulatory properties of SP1 revealed in our study show that it has real potential as a technology for crop improvement. For example, it could be used to develop early or late fruiting varieties of fleshy fruits or 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 plastids can have such far-reaching consequences for fruit ripening in tomatoes.”
The discovery was published on May 18, 2021, in the journal Nature Plants.
