biostudies-literatureRenoud SAgence Nationale de la Recherche325https://www.ebi.ac.uk/biostudies/studies/S-EPMC8877547biostudies-literatureUnknown10(2)The impact of inoculated plant growth-promoting rhizobacteria (PGPR) on its host physiology and nutrition depends on inoculum level. Whether the impact of the inoculated PGPR on the indigenous rhizosphere microbiota also varies with the PGPR inoculum level is unclear. Here, we tested this issue using the PGPR <i>Azospirillum lipoferum</i> CRT1-maize model system, where the initial seed inoculation is known to enhance maize growth and germination, and impacts the maize rhizomicrobiota, including microbial functional groups modulating plant growth. <i>A. lipoferum</i> CRT1 was added to the seeds at standard (10^5-6 cells.seed^-1) or reduced (10^4-5 cells.seed^-1) inoculation levels, in three fields. The effect of the two PGPR formulations was assessed MicroorganismsEffect of Inoculation Level on the Impact of the PGPR <i>Azospirillum lipoferum</i> CRT1 on Selected Microbial Functional Groups in the Rhizosphere of Field Maize.PMC8877547ANR-12-AGRO-0008Deep Impact (ANR-20-PCPA-0004)Abrouk DMoenne-Loccoz YWisniewski-Dye FMuller DRenoud SLegendre LPrigent-Combaret CfalseEffect of Inoculation Level on the Impact of the PGPR <i>Azospirillum lipoferum</i> CRT1 on Selected Microbial Functional Groups in the Rhizosphere of Field Maize.The impact of inoculated plant growth-promoting rhizobacteria (PGPR) on its host physiology and nutrition depends on inoculum level. Whether the impact of the inoculated PGPR on the indigenous rhizosphere microbiota also varies with the PGPR inoculum level is unclear. Here, we tested this issue using the PGPR <i>Azospirillum lipoferum</i> CRT1-maize model system, where the initial seed inoculation is known to enhance maize growth and germination, and impacts the maize rhizomicrobiota, including microbial functional groups modulating plant growth. <i>A. lipoferum</i> CRT1 was added to the seeds at standard (10^5-6 cells.seed^-1) or reduced (10^4-5 cells.seed^-1) inoculation levels, in three fields. The effect of the two PGPR formulations was assessed 2022-01-01T00:00:00Z2022 Jan2026-04-08T18:24:13.381Z2025-02-19T05:04:57.457ZS-EPMC88775473520878010.3390/microorganisms10020325