Cannabidiolic Acid Synthase

Cannabidiolic acid synthase (CBDAS) is the enzyme responsible for catalyzing the conversion of cannabigerolic acid (CBGA) into cannabidiolic acid (CBDA), the acidic precursor to CBD. The presence and expression level of functional CBDAS genes determine a plant's capacity to produce CBD-dominant or CBD-rich chemotypes. Plants lacking active CBDAS typically express THCAS instead, leading to THC-dominant phenotypes, making this enzymatic pathway a critical branching point in cannabinoid biosynthesis. CBDAS activity is controlled by recessive alleles, meaning both copies of the gene must be functional for robust CBD production. Understanding CBDAS genetics is foundational to breeding CBD-rich cultivars and studying cannabinoid inheritance patterns.

Breeders select for CBDAS-positive lines by screening for CBD content and conducting crosses between confirmed CBD-producing parents. Molecular genotyping of CBDAS loci accelerates identification of homozygous CBD-producing individuals, reducing phenotypic screening cycles in breeding programs.