LAUSR

BACKGROUND Nowadays, new-type fertilizer applications have become a new trend in modern agriculture. Previous studies have shown that amino acid fertilizers can improve crop yield and quality. However, their effects on crop rhizosphere ecology and these ecological impacts on crop yield are largely unknown. In this study, we evaluated the promoting effects of a water-soluble amino acid fertilizer (WAAF) on tomatoes and its ecological effects on rhizosphere bacterial communities by greenhouse pot experiments. RESULTS The results showed that WAAF could more effectively promote the growth of tomatoes and improve the quality of fruits compared with the control water-soluble chemical fertilizers. Interestingly, WAAF showed a different regulating pattern on root exudates and increased the secretion of 17 major water-soluble root exudates which included hexadecanoic acid and 3-hydroxy-γ-butyrolactone. Further, WAAF noticeably affected the composition, abundance and beta-diversity of rhizosphere bacterial communities and strengthened the potential relationships between community members. WAAF showed a significant selective enrichment ability and recruited some members of the genera such as Cupriavidus, Ralstonia, Chitinophaga, Gemmatimonas, Mitsuaria, Mucilaginibacter, Paracoccus, Sphingopyxis, and Variovorax. Network analysis and functional prediction implied that besides fertilizer effects, the recruiting of beneficial microbes involved in chemotaxis and biofilm formation was also a non-negligible factor in tomato yield and quality improvement. CONCLUSION Taken together, our study preliminary revealed the ecological and recruiting effects of WAAF on rhizosphere microbes and potentially beneficial microbiota, and provided a basis for amino acid fertilizer regulation of rhizosphere ecology to improve soil health and further improve crop yield and quality. This article is protected by copyright. All rights reserved.