Top notes of sex? Engineered plants trick pests using sex perfume

Researchers have now unlocked ways to synthetically engineer plants such as tobacco into pheromone factories that only require sunlight and water. This is made possible by creating genetic modules with the instructions to build new molecules.

“Synthetic biology can allow us to engineer plants to make a lot more of something they already produced or we can provide the genetic instructions that allow them to build new biological molecules, such as medicines or these pheromones,” said Dr. Nicola Patron, head of the Synthetic Biology Group at the Earlham Institute and the lead on this new research.

Dr. Patron and her team worked with scientists at the Plant Molecular and Cell Biology Institute in Valencia to engineer Nicotiana benthamiana- a species of tobacco previously used to produce Ebola antibodies and coronavirus-like particles for use in vaccines- to release moth sex pheromones.

Coercing plants to continuously build these molecules has its drawbacks. The team introduced a few molecular switches to the plant’s DNA to regulate production like an on-off switch.

“Too much energy is diverted away from normal growth and development,” explained Dr. Patron. “The plants are producing a lot of pheromones but they’re not able to grow very large. Our new research provides a way to regulate gene expression with more subtlety, ” she added. 

Moth pheromones are often a blend of two or three molecules in specific ratios. In their tests, the team observed that copper sulfate could finely tune the control of the genes mimicking the sex pheromones of species such as navel orangeworms and cotton bollworms, allowing better control over the timing and level of gene expression.

Copper sulfate is readily available, cheap, and approved for use in agriculture, which signifies the viability of routinely using plants to produce a wide range of valuable natural products. 

An advantage of using plants to build complex molecules over chemical processes is its lower cost. Collaborators of the research are currently extracting these plant-made pheromones and studying them in comparison to female moths. 

Dr. Patron envisions a future where we may see greenhouses full of plant factories- a greener, cheaper, and more sustainable way to manufacture complex molecules.

Study Abstract

Researchers part of the SUSPHIRE project describe their breakthroughs in engineering tobacco plants to release pheromones that mimic moth species. This achievement is seen as a replacement for pesticides.