“Plant growth-promoting rhizobacteria (PGPR) establish beneficial associations with plants, enhancing nutrient uptake, growth, and stress tolerance.
Cannabis sativa L., a medicinal plant producing over 300 specialized metabolites with relevant medicinal properties, remains underexplored for PGPR influence on its metabolism. This study assessed the ability of four PGPR taxa: Bacillus, Pseudomonas, Flavobacterium, and Burkholderia to colonize roots and modulate cannabinoid metabolism.
Two Δ9-tetrahydrocannabinolic acid (THCA) drug-type C. sativa cultivars, Amnesia Haze and Gorilla Glue, were tested. Plants grown hydroponically were inoculated under controlled conditions. Root colonization was confirmed via endophyte-specific assays.
Phenotypic analyses revealed no effects on plant phenotype, while chemical analyses revealed a response shared across taxa and cultivars. Bacterial inoculation increased the precursor cannabinoid Cannabigerolic acid (CBGA) concentration significantly by +27.37% while reducing Δ9-tetrahydrocannabinol (Δ9-THC) by -15.76%. The CBGA/THCA and THCA/CBDA ratios shifted significantly, indicating a favored CBGA accumulation and CBDA production, respectively.
PGPR treatments reduced in vivo and post-harvest decarboxylation of THCA into Δ9-THC, preserving the acidic cannabinoid profile. Under a standardized, soilless hydroponic regimen with a single shared reservoir and identical fertigation across groups, PGPR colonization was associated with shifts in cannabinoid metabolism and reduced decarboxylation.
This study demonstrates that PGPR can influence the specialized metabolism of high-THCA C. sativa, offering insights into sustainable cultivation and pharmaceutical exploitation of this relevant medicinal plant species.”
https://pubmed.ncbi.nlm.nih.gov/41578722
“Plants and bacteria share a long history that spans over a 100 million years. Since then, they have co-evolved to form complex relationships that facilitate the survival of both.”
“PGPRs can promote growth in several ways.”
“The findings and methodology of this research lay the groundwork for further evaluating and exploiting the potential beneficial relationship between PGPRs and C. sativa and implementing their sustainable applications in the agricultural, biotechnological, and pharmaceutical sectors.”