Greenhouse and field evaluation of bacterial endophytes from Cannabis sativa and Chelidonium majus reveals beneficial stage-dependent growth and yield responses in common bean.

Kaddoura M.; Amaya-Quiroz L.; Samsatly J.; Meglouli H.; George S. · Frontiers in plant science · 2026

**Background & Methods** This study evaluated bacterial endophytes (Bacillus subtilis strains BS-114 and BS-120, and Pseudomonas wadenswilerensis PPW-26) isolated from Cannabis sativa and Chelidonium majus as plant growth-promoting agents in yellow bean. Researchers conducted sequential evaluations under in vitro, greenhouse, and field conditions, with physiological measurements, gene expression analysis, and soil microbial assessment. **Key Findings** • Early developmental enhancement: BS-114 increased seed germination by 19.1% and seedling total root length by 71.3%, while PPW-26 increased root biomass by 61.7% compared to non-inoculated controls. • Greenhouse reproductive improvements: BS-114 improved reproductive development with 47.4% increase in bud count, 60.2% increase in immature pod count, and 42.1% increase in pod fresh mass. Cell-free extracts of BS-114 produced the highest cumulative pod fresh mass (+94.2%). • Field yield validation and physiological mechanisms: The BS-114+BS-120 consortium increased field yield by 32.65%, comparable to NPK fertilizer (+37.76%). Multiple physiological pathways were activated, including photosynthetic rate (+175.8%), stomatal conductance (+306.9%), nitrogen-fixation genes (nifH expression, +5.62 log2FC), and auxin/cytokinin signaling pathways. **Dosage & Administration** Not reported. The study does not specify bacterial inoculum concentrations, application methods, or timing protocols suitable for clinical or agricultural standardization. **Safety & Adverse Effects** Not reported. The study focused on beneficial effects and did not document adverse effects, toxicity, or safety concerns associated with bacterial endophyte treatments. **Evidence Quality** This is a comprehensive multi-stage evaluation study with substantial methodological rigor, including controlled greenhouse experiments, field validation, and molecular mechanisms investigation. However, limitations include: (1) evaluation limited to a single crop species (common bean); (2) unclear whether findings from Cannabis sativa and Chelidonium majus endophytes translate directly to other plant systems; (3) moderate soil nutrient variation and limited microbial diversity shifts suggest incomplete mechanistic understanding; and (4) field results represent a single growing season without multi-year validation. The study provides moderate-to-good evidence for bacterial endophytes as growth-promoting agents but requires further investigation for broad agronomic application.

More recent cannabis research