Phosphorus deficiencies invoke lipids-like enrich in sweetpotato rhizosphere to stimulate bacterial inositol phosphate metabolism

Purpose: Rhizosphere is the key part of belowground interaction between plant, microbes and soil. Beneficial interactions between plant roots and rhizosphere microorganisms are pivotal for plant fitness. Given the effort to improve sweetpotato phosphorus (P) efficiency, it is important to understand the adaptive strategies of sweetpotato rhizosphere under limited P availability. The aim of this study was to explore the variation of bacterial community and metabolite profiles of sweetpotato rhizosphere and their interactions under low P stress. Method: Rhizosphere samples collected from sweetpotato (Shangshu 19) grown in long-term (41 years) application nitrogen (N) and potassium (K) fertilizers (NK) and N, P and K fertilizers (NPK) soils were analyzed the bacterial community and metabolite profiles by 16S rRNA high-throughput sequencing and liquid chromatography-mass spectrometry (LC-MS), respectively. Conclusion: Different fertilization treatments significantly affected the abundances of rare genus in Shangshu 19 rhizosphere. The COG and KEGG enrichment analysis showed the function of bacterial correlated to sugar metabolism and inositol phosphate metabolism were significantly enhanced under low P stress. LC-MS analysis obtained similar results that galactose metabolism and phospholipase D signaling pathway were the top 2 differential metabolic pathways. Our results suggested that the bacteria of Shangshu 19 rhizosphere may use sugars as energy material to respond to low P stress by changing inositol phosphate metabolism. The increases of lipid-like substances played a connecting role, it was produced by sugar metabolism, and then entering mevalonate pathway activate inositol phosphate metabolism. These results have important practical significance for optimizing sweetpotato cultivation system.