Israel’s Institute of Soil Water & Environmental Sciences researchers investigated how magnesium (Mg) supply impacts cannabinoid and terpene biosynthesis in cannabis. Magnesium is an essential mineral-nutrient for many types of plants, including cannabis, and it is required for enzyme activity in the biosynthesis pathway of cannabinoids and terpenes. The findings, published in the Journal of Cannabis Research, highlighted the optimal magnesium supply for plant function, as well as deficiency and toxicity concentration thresholds for the reproductive stage.
The researchers grew cannabis plants under five specific magnesium levels, ranging from 2 to 140 mg L−1 (ppm), to determine the optimal supply concentrations for plant morphophysiology and secondary-metabolite production. They developed cannabinoid and terpene profiles of inflorescences from two developmental orders.
The results revealed high sensitivity of cannabinoid and terpene biosynthesis to magnesium. The supply treatment of 35 mg L−1 optimized metabolite activity. This amount resulted in enhanced yield quantity as well as quality (high secondary metabolite production). Lower or higher magnesium availability suppressed cannabinoid and terpene production. Magnesium deficiency significantly decreased the inflorescence (flower) biomass. Over-supply levels of 70–140 mg L−1 Mg reduced reproductive biomass by 12.5%, but these levels did not harm secondary-metabolism.
Examining the concentrations of all micronutrients in the leaves indicated a correlation between micronutrient concentrations and magnesium supply. The researchers noted the highest concentrations in plants under magnesium deficiency (2 mg L−1) and decreased as magnesium supply increased.
Another key finding observed some variations in magnesium’s effect on mineral distribution to the plant organs between the reproductive and the vegetative stages. This finding suggested that developmental stage dependency plays a role in magnesium’s impact.
The researchers emphasized the need for additional research that sheds light on how magnesium supply impacts various cultivars with differing cannabinoid and terpene profiles and growing conditions.
Source: Journal of Cannabis Research