A fast-growing plant in the sunflower family could provide a new source of cannabinoids, a class of phenolic compounds found in cannabis1. The plant, genetically distinct from cannabis, produces the cannabinoids in its aerial parts.
More than 40 years ago, researchers discovered a cannabinoid called cannabigerolic acid (CBGA) in the herb Helichrysum umbraculigerum. Until now, no studies have replicated this finding.
An international research team grew the plant in a greenhouse facility and collected its leaves to study the enzymatic pathways and related genes for cannabinoid synthesis. They found that CBGA accumulates in all the aerial parts of the plant, reaching up to 4.3% of dry weight in leaves.
The team, which included researchers at the CSIR-National Chemical Laboratory in Pune, identified that biosynthesis of cannabinoids in leaves and flowers arises via five parallel pathways. They detected three core enzymes and two previously unknown types, which are absent in Cannabis, that generate previously unreported cannabinoids.
The core cannabinoid pathway consists of similar types of enzymes and reactions as in Cannabis. The enzymes that enabled H. umbraculigerum to produce cannabinoids evolved independently in this lineage through multiple instances of gene duplication.
These findings prove a case of parallel evolution in cannabinoid formation in two genetically distant plant families and provide new enzymes for metabolic engineering. The study demonstrates the potential for another perennial, fast-growing, commercially viable plant source for bioactive cannabinoids with therapeutic potential.
