Isoprenoid Biosynthesis

Isoprenoid biosynthesis refers to the metabolic pathways through which cannabis plants produce terpenes, cannabinoids, and other volatile compounds from simple carbon precursors. These biosynthetic routes—primarily the mevalonate (MVA) and methylerythritol phosphate (MEP) pathways—generate the C5 isoprene building blocks that form larger isoprenoid molecules. Cannabinoids like THC and CBD are technically isoprenoids (diterpenes), as are the monoterpene and sesquiterpene components of cannabis aroma profiles. Understanding isoprenoid biosynthesis is central to breeding programs seeking to stabilize chemotype expression, enhance terpene diversity, or explore rare cannabinoid pathways. Genetic variation in enzyme activity at multiple steps of these pathways contributes to the chemical phenotype variation observed across cultivars.

Breeders working with isoprenoid biosynthesis focus on selecting for stable expression of specific terpene synthases and cannabinoid synthases. Lineage records frequently report that cultivars selected for high expression of particular monoterpenes or cannabinoid ratios often carry heritable variation in the enzymes governing these biosynthetic steps.