Nightshade’s deadly berries have been the source of legend for centuries, but it turns out that tomatoes, a close relative, have a similar defense mechanism – albeit one that makes them safe for human consumption.
Tomatoes and other Solanaceae family members produce toxic steroidal glycoalkaloids as a natural defense against pests. However, researchers at Sichuan University have discovered the genetic mechanisms behind the transformation of these toxins into something more palatable and less deadly in tomatoes.
The process involves a protein called DML2, which regulates gene expression by removing methyl groups from specific genes involved in suppressing the toxins. This epigenetic regulation allows the plant to control its toxin production and ensures that only ripe fruits contain high levels of toxic compounds.
By studying other related plants, scientists found that DML2-driven DNA demethylation increased during domestication, changing the plants’ characteristics from small berry producers to large red fruit creators. This shift ultimately made tomatoes a healthier crop for humans, allowing them to be safely consumed in moderation.
The research, published in Science Advances, sheds new light on the complex mechanisms behind plant defense and highlights the intricate relationship between tomato toxicity and human consumption.
Source: https://www.sciencealert.com/tomatoes-dont-kill-humans-and-we-just-figured-out-why