Deciphering the Influence of Bacillus Subtilis Strain Ydj3 Colonization on the Vitamin C Contents and Rhizosphere Microbiomes of Sweet Peppers

Bacillus subtilis strain Ydj3 was found to enhance the growth and quality of sweet peppers by promoting seed germination and increasing daily germination speed to 131.5 seeds/day compared to 73.8 seeds/day in the control. The strain exhibited chemotaxis toward root exudates, leading to root colonization and enhanced root hair growth. Monthly applications of Ydj3 in a commercial greenhouse significantly increased sweet pepper yield, fruit weight, and vitamin C content. Additionally, the rhizosphere bacterial community composition shifted, with Bacillus becoming the dominant genus. These findings suggested that Ydj3 improved sweet pepper fruit quality and growth through root colonization and rhizosphere modulation.