Finally, researchers appear to have identified the actual pathway of exactly how UVB affects THC production. While the analysis is somewhat technical, we’ll do our best to outline the results below. Ready?
UVB causes damage in plants in much the same way as it damages human skin, and plants created defenses against UVB in the form of a protein called UVR8.
UVR8 is a protein molecule which senses UV, and then “tells” plant cells to change their behavior. Exactly how UVR8 molecules sense UV was recently discovered and is pretty interesting. UVR8 is what chemists call a “dimer,” which simply means that it’s made of two structurally similar protein subunits. When UV light hits the two protein subunits in UVR8, their charge weakens and they break apart. To help visualize this, imagine rubbing two balloons against one another. The balloons will stick together because of a static charge. Now imagine the balloons get rained on. The water takes the static charge with it and the two balloons fly apart. In this example, the balloons are the two protein subunits and the rain is UV light cascading down on the plant cell. After the protein subunits break apart, they head to the cell nucleus to deliver their information.
One of these changes caused by this reaction is very important in your cannabis garden. UV stress stimulates cannabis’ production of chemicals via the phenylpropanoid pathway, specifically malonyl-CoA and phenylalanine. Why is this important? Because cannabis uses malonyl-CoA to make Olivtol, which it in turn uses to make THC. So finally the specific pathway which increases Cannabis potency when exposed to UV light is understood, and we can use this information to our advantage.