Bacillus subtilis stimulates plant growth and production of bioactive components in saffron

The effects of B. subtilis on the morphology and physiology of saffron were investigated using two types of soils. Three different bacterial suspensions were applied at 14-day intervals to treat saffron. Morphological attributes were recorded, and the amounts of α-crocin and safranal in the stigma extracts were quantified. The longest stigma, petal, and leaf were observed in the treated groups with 10⁵ and 10⁸ cfu/ml. The highest weight of stigma per corm belonged to the treated groups with 10² cfu/ml in unsterile soil and 10⁵ and 10⁸ cfu/ml in sterile soil. Treatment with 10² and 10⁸ cfu/ml caused a significant increase in safranal production in sterile and unsterile peat/perlite. While treatment with 10⁵ and 10⁸ cfu/ml in sterile peat/perlite and exposure to 10² cfu/ml in unsterile peat/perlite soil resulted in an increase in α-crocin. The data showed that B. subtlis triggers the morphological and physiological processes in saffron.