Growth performance and metabolic changes in lettuce inoculated with plant growth promoting bacteria in a hydroponic system

Crop cultivation in hydroponic systems is often exposed to both abiotic and biotic stresses, which impact growth. One possible approach to alleviating these stresses and improving plant growth is by utilizing plant growthpromoting bacteria (PGPB). Our previous study has shown the efficacy of two PGPB strains, Pseudomonas lundensis UB 53 and Pseudomonas migulae UB 54, in promoting growth and stimulating the generation of plant defense enzymes to mitigate biotic and abiotic stress in lettuce grown in a nutrient film technique (NFT) hydroponic system. Therefore, this study purposed to assess metabolic changes in lettuce in response to P. lundensis UB 53 and P. migulae UB 54 inoculation in a NFT hydroponic system. The results exhibited that these bacteria enhanced IAA accumulation and lettuce growth in a NFT hydroponic system. A total of 58 metabolites were detected in the root samples, including primary and secondary metabolites. It also influenced 12 metabolic pathways, with emphasis on five pathways, including the metabolism of alpha-linolenic acid, inositol phosphate, pyruvate, sulfur, and the phosphatidylinositol signaling system. These results highlight the significant roles of myo-inositol and acetic acid in metabolic pathways during the interaction between lettuce and PGPB.