Two Main Tropane Alkaloids Variations of Black Henbane (Hyoscyamus niger) Under PGPRs Inoculation and Water Deficit Stress Induction at Flowering Stage

Background: Plants infection with microorganisms as well as physical factors such as osmotic stresses especially drought stress induced particular secondary metabolite production. Objective: Plant root and shoot hyoscyamine (HYO) and scopolamine (SCO) variations were investigated under three water deficit stress (WDS) levels as 30 (W1), 60 (W2) and 90 % (W3) water depletion of field capacity and Pseudomonas putida (PP) and P. fluoresence (PF) strains inoculation at flowering stage. Methods: Seedling radicles and culture media were inoculated with PP and PF (109 CFU/ml) strains. Monitoring of soil moisture levels was conducted using gravimetric method. Alkaloids extracted were identified by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. Results: Results revealed that HYO was the prevalent alkaloid in root and shoot organs. The highest ratio of SCO to HYO (0.53) and the highest alkaloids both HYO and SCO content in root and shoot was observed in W3PF treatment. The largest total alkaloids (HYO+SCO) yield (25.7 mg.plant-1) was showed in PP treated plants under W1 conditions. Conclusion: Integrative use of effective Pseudomonades strains and WDS sounds to be an encouraging and eco-friendly strategy for increasing tropane alkaloids yield and content in Hyoscyamus niger root and shoot parts.