Advanced Microscopy Reveals Highest Potency of Cannabis

Research from the University of British Columbia (UBC) has revealed that a higher quantity of the microscopic, mushroom-shaped hairs that cover the marijuana plant are what determine the potency of the cannabinoid and fragrance.

In a study published in The Plant Journal, UBC researchers used a combination of advanced microscope techniques and chemical profiling to examine the internal structures and development of individual microscopic hair, called trichomes, in a fast-flowering hemp variety of Cannabis sativa called Finola. The researchers’ findings proved a long-held belief among cannabis enthusiasts that the trichomes hold the richest source of THC- and CBD-forming metabolites and fragrance-giving terpenes.

“Trichomes are the biochemical factories of the cannabis plant, and this study is the foundation for understanding how they make and store their valuable products,” said co-lead author Teagen Quilichini, a postdoctoral fellow at the UBC Department of Botany and Anandia Laboratories Inc. Quilichini noted that research on the plant has been hampered by past legal issues concerning marijuana, which along with prohibiting the use of the drug also made it illegal for researchers to study it.

The team found that under ultraviolet light, the stalked trichomes emitted a bright blue color and contained a large, distinctive pie-shaped disc of cells. The smaller sessile trichomes, which do not have a stalk, emitted a red color, had smaller secretory discs, and produced fewer fragrant terpenes.

“We also found that [stalked trichomes] grow from sessile-like precursors and undergo a dramatic shift during development that can be visualized using new microscopy tools,” said co-lead author Sam Livingston, a Ph.D. candidate at UBC botany.

According to Livingston, UV light could help researchers monitor trichome maturity on flowers and inform optimal harvest times.

The researchers said they plan next to investigate how trichomes export and store the CBD-metabolites they produce.

“Trichomes store the metabolites in their cell walls,” Livingston said. “And what’s really astounding is that such high levels of product should be toxic to the cells, so we want to understand how they manage this.”