Pretty much everybody (I think) knows that getting a tomato from the grocery store is a completely different experience than sinking your teeth into one just picked off of a plant in your back yard. The tastes do not even start to compare with each other. The reason for this is that in commercial operations, the tomatoes are picked off the vine while still green so that they’re nice and red (instead of disintegrated) when they get to your table.
The chemical compounds in a tomato responsible for its red color are called carotenoids. When left on the vine, these chemicals are naturally produced in reckless abandon. When taken off the vine prematurely, not so much.
A recent paper from Purdue University is looking to change that. By moving into the budding field of metabolic engineering, researchers determined that they could tap into the molecular building blocks of carotenoids to boost their production in fruits and other flowering plants. By fusing two of the available molecular building blocks to build an intermediate product, the researchers found they could nudge further modification of the chemicals into the sweet stuff of back yard garden lore.
You might note that I haven’t said anything yet about chemicals that give tomatoes their taste. (Yup, look back. All I mentioned was the color.) Here’s where that bit comes in.
A tomatoes juicy goodness comes from chemicals called terpenes, which are structurally extremely similar to the red-inducing carotenoids. Figure out how to bioengineer one, and you should be able to easily move to the other. And if you’re in a laboratory setting, which one would you try to engineer first? The chemicals that give taste and scent, very subjective characteristics that can only be measured by painstakingly tasting each and every specimen, or the ones that determine redness, which can easily be quickly measured by a simple glance?
According to author Natalia Dudareva, distinguished professor of biology, this research is a first step to bringing better tasting tomatoes to your local megamart. But beyond that, terpenes are also important in attracting pollinators and defending themselves against pests. So metabolically engineering their quantities and types could have many more benefits than just a better tasting marinara.
The paper, “Cytosolic monoterpene biosynthesis is supported by plastid-generated geranyl diphosphate substrate in transgenic tomato fruits,” was published in The Plant Journal by Dudareva and colleague Michael Gutensohn and collaborators from the University of Michigan and Israel.