The persistence and performance of phosphate-solubilizing Gluconacetobacter liquefaciens qzr14 in a cucumber soil

Abstract

The persistence and performance of plant growth-promoting microorganisms (PGPMs) in soil are considered critical features for effectiveness, yet they are poorly understood. Here, we investigated the colonization and activity of a new PGPM, phosphate-solubilizing Gluconacetobacter liquefaciens qzr14, in a pot culture experiment using cucumber as test crop for 20 days. The number of G. liquefaciens and bacterial diversity in the rhizosphere and bulk soil were monitored by real-time PCR and DGGE, respectively. Soil phosphorus and cucumber biomass were also examined. G. liquefaciens qzr14 effectively colonized the rhizosphere soil (bacterial density ranging from 2.70 9 10 8 to 1.18 9 10 9 copies per gram dry soil). G. liquefaciens qzr14 inoculation had significantly positive effects on bacterial diversity (BD) of the rhizosphere and bulk soil and the ratio of soluble phosphorus to total phosphorus (SP/TP). The number of G. liquefaciens in the rhizosphere soil was significantly related to SP/TP and the BD of the rhizosphere and bulk soil. BD in rhizosphere soil was significantly related to SP/TP and BD in bulk soil. Based on the results of correlation analysis, we inferred that the introduced G. liquefaciens qzr14 effectively colonized the rhizosphere of cucumber, and then expanded its bacterial community by solubilizing soil phosphorus. The expanded bacterial communities might promote cucumber growth by some new functions.

The Importance of Considering Levels of P and N Fertilization to Promote Beneficial Interaction between Rapeseed and Phosphate-Solubilizing Bacteria

“…These overall results thus confirm the promising potential of using Pfaba as a PGPR and, more interestingly, as a PSB strain to sustain rapeseed nutrition in low phosphorus conditions through direct processes linked to phosphorus solubilization, as previously hypothesized by Amy et al [43]. These results are consistent with previous studies concerning the deployment of such microbial biointrants on numerous plant species [53][54][55][56][57][58], confirming the powerful potential of PGPR/PSB utilization. This study also demonstrates that beneficial effects observed on plants are directly due to Pfaba inoculation, as rapeseed was grown in axenic conditions and independent of associated soil microbial community structure in the soil surrounding the roots.…”

16S rRNA Gene Amplicon Based Metagenomic Signatures of Rhizobiome Community in Rice Field During Various Growth Stages

“…However, available forms of phosphate even in fertile soil is generally low at sub-micromolar levels (Arif et al, 2017). Phosphate solubilizing bacteria plays a critical role in solubilization of various phosphate compounds making it available to the plants (Arif et al, 2017), counteract soil calcification (Adnan et al, 2017), and enrich microbial diversity (Wang J. et al, 2017). Plant hormones are one of the major determinants of rooting and shooting (Habib et al, 2016), enhances drought resistance (Jung et al, 2015), up-regulates nitrogen fixation (Defez et al, 2017), and as bio-fertilizers (Shahzad et al, 2017).…”

Traits-Based Integration of Multi-Species Inoculants Facilitates Shifts of Indigenous Soil Bacterial Community

“…Microbial co-inoculants might promote cucumber yield by both the direct and indirect effects. The direct effects of microbial inoculants promote plant growth had been extensively described ( Colla et al, 2015 ; Wang et al, 2017 ). Nowadays, some works had been suggested that regulation of soil bacterial community structure is one of the plant growth-promoting mechanisms of microbial inoculants ( Kang et al, 2013 ; Rodriguez-Caballero et al, 2017 ).…”