Application of Bacillus velezensis NJAU-Z9 Enhanced Plant Growth Associated with Efficient Rhizospheric Colonization Monitored by qPCR with Primers Designed from the Whole Genome Sequence

Abstract

Plant growth-promoting rhizobacteria (PGPR) have been reported to influence plant growth, yield, and nutrient uptake by an array of mechanisms. Uncovering the behavioral dynamics of PGPR is one of the most important issues necessary for understanding their functional performances. In this study, strain NJAU-Z9 which was found to possess complex functions and efficient rhizospheric colonization ability was selected from plenty of bacterial strains isolated randomly from the pepper rhizosphere soil and identified as Bacillus velezensis. Repeated seedling nursing tests performed absolute growth-promoting advantage for the novel isolated strain. After that, primers for the quantitative detection were designed based on its whole genome sequence (WGS), and a real-time PCR method was utilized to explore strategies for monitoring the strain in natural soil and in the pepper rhizosphere. Results showed based on the whole genome, two primers were identified as NJAU-Z9-specific quantitative PCR primers. Two seasonal pot experiments demonstrated that strain NJAU-Z9 effectively colonized the rhizosphere measured by the novel abundance detecting strategy, improved plant growth, and showed a positive correlation between bacterial number and biomass. This study offers a strategy based on a real-time PCR method for directly monitoring B. velezensis strain NJAU-Z9 in the soil and the rhizosphere and provides a reference for the quantitative study of other PGPR strains based on WGSs.Electronic supplementary materialThe online version of this article (10.1007/s00284-018-1563-4) contains supplementary material, which is available to authorized users.

The Endophytic Bacteria Bacillus velezensis Lle-9, Isolated from Lilium leucanthum, Harbors Antifungal Activity and Plant Growth-Promoting Effects

“…The improved growth performance in the Asiatic lilium hybrids 'Tresor' upon inoculation of Lle-9 might be due to the growth-promoting effects as were evaluated through several qualitative and quantitative tests. Previous studies also reported similar growth improvement when plants were inoculated with the isolated strains of Bacillus velezensis [75,40]. The isolated B. velezensis strain Lle-9 showed antagonistic effects against the broad-spectrum fungal pathogens.…”

Seed biopriming with P- and K-solubilizing Enterobacter hormaechei sp. improves the early vegetative growth and the P and K uptake of okra (Abelmoschus esculentus) seedling

“…In particular, PGPB exerts beneficial effects on plant growth through several ways: facilitating the acquisition of soil nutrients by asymbiotic N 2 -fixation and inorganic P and K solubilization; modulating the level of phytohormone such as indole-acetic acid (IAA), cytokinins, and gibberellins (GA3); resisting against phytopathogen [1]. At present, majority of field-tested bacterial taxonomic groups affiliated to PGPB belonged to ranges of genera: Azospirillum, Rhizobium, Agrobacterium, Rhizobium (Alphaproteobacteria); Azoarcus, Burkholderia, (Betaproteobacteria); Acinetobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Serratia, (Gammaproteobacteria); Bacillus, Frankia (gram-positive bacteria) [7][8][9][10].…”

Elucidating the Rhizosphere Associated Bacteria for Environmental Sustainability

“…Capsicum annuum L. The soil amended with Bacillus velezensis improves seedling height, stem diameter, and yields compared to those pepper plants grown on un-amended soil [37] Arabidopsis thaliana…”