Cannabis sativa L., a dioecious diploid plant, has gained global attention for its multifaceted applications in medicine, fiber production, and oil extraction. This study explores the intricate transcriptomic landscape and cannabinoid biosynthesis of two distinct Indian cannabis landrace accessions: CIM-CS-39, an elite strain with a genetic potential for high tetrahydrocannabinol (THC > 20%), and CIM-CS-64, recognized for its elevated cannabidiol potential (CBD > 10%). Employing a de novo RNA-Seq assembly framework across six tissue-specific libraries, significant genetic variants and expression patterns associated with chemotypic divergence were unveiled. At the specific short-day harvest stage (Day 72), quantitative HPLC analysis confirmed distinct profiles, revealing a high accumulation of total THC (9.67% w/w) in CIM-CS-39 and total CBD (4.44% w/w) in CIM-CS-64, with negligible cross-contamination (< 0.3% THC in the high-CBD line). Differential gene expression (DEG) analysis identified over 5,000 significantly altered transcripts between the accessions. Notably, core structural genes in the cannabinoid biosynthetic pathway, including tetrahydrocannabinolic acid synthase (THCAS) and cannabidiolic acid synthase (CBDAS), exhibited highly polarized expression profiles that tightly synchronized with their respective chemotypic accumulation matrices. These results validate the genomic integrity of localized landraces and provide critical molecular blueprints and specific synthase targets for marker-assisted breeding and biotechnological strategies aimed at optimizing therapeutic cannabis strains.
Aftab et al. (2026) studied this question.