Biology subjects

Babalola, O. O.

Publications and source records attributed to Babalola, O. O..

4 recordsLinked to original sources

bioRxiv2026

Unravelling genomic and functional traits of two biocontrol and plant growth-promoting Pseudomonas endophytes

Plant growth-promoting bacterial endophytes represent a sustainable strategy for enhancing agricultural productivity while reducing reliance on synthetic fertilizers and pesticides. This study focused on the genomic and functional characterization of two endophytic bacterial strains, R11F and R19M, isolated from bean and maize roots, respectively. Comparative analyses based on 16S rRNA gene sequences, average nucleotide identity (ANI), and genome-to-genome distance calculations (GGDC) classified both isolates as Pseudomonas palleroniana. Comparative genomic analyses revealed highly conserved genomes containing genes associated with plant colonization, phosphate solubilization, stress adaptation, heavy metal resistance, and hydrocarbon degradation. Genome mining further identified 17 and 18 biosynthetic gene clusters (BGCs) in R11F and R19M, respectively, including non-ribosomal peptide synthetases (NRPS), pyoverdine, NRP-metallophores, RiPP-like compounds, arylpolyenes, {beta}-lactones, terpenes, NAGGN, and hydrogen cyanide. Strain-specific BGCs associated with syringomycin and viscosin biosynthesis were identified in R11F, whereas R19M harbored clusters related to asplenin and kolossin biosynthesis. In vitro assays confirmed indole production, phosphate solubilization, and siderophore production, as well as the ability of both strains to grow in nitrogen-free medium. Both strains significantly inhibited the growth of Fusarium oxysporum, Phytophthora cinnamomi, and Colletotrichum gloeosporioides. Furthermore, plant inoculation assays demonstrated host-dependent growth promotion, with R11F showing the most consistent improvements in plant growth parameters in tomato, wheat, and lentil. Overall, the integration of comparative genomics and experimental validation demonstrates that P. palleroniana R11F and R19M possess complementary traits associated with plant growth promotion, pathogen suppression, saline stress adaptation, and bioremediation.

microbiology↗

bioRxiv2023

The biodiversity of eukaryotes in Bambara groundnut rhizosphere

Bambara groundnut has been observed to resist pest and drought, and still able to produce enormous yield when cultivated on poor soil. The advantages of the crop to farmers includes the fact that it produces enormous yield with very low agricultural input. The aim of the present study was to determine the taxonomic and microbial diversity, and identification of eukaryotic organisms in Bambara groundnut rhizosphere using microbiomeanalyst platform. A total of ten soil samples corresponding to the different growth stages were collected from Bambara groundnut rhizosphere over interval period of 4 weeks at North-West University agricultural farm, Mafikeng campus. These samples were assessed for the presence of eukaryotic organisms through polymerase chain reaction (PCR) of 16S ribosomal ribonucleic acid (rRNA) gene. Metagenomics analysis using culture-independent technique (next generation sequencing (NGS)) by Paired end illumina-Miseq technology sequencing with the prospect of discovering novel eukaryotes with plant growth promoting features was used. Statistical analysis was carried out to profile and confirm identities of detected organisms. Fifty-nine (59) features were detected from the 10 samples by microbiomeanalyst under data normalization and data cleaning. Taxonomic analysis showed that, 69% of the eukaryotes in the samples were Peronosporales while Thalassiosiraceae and others were 30% and 1% respectively. There was profound variance difference in the rhizosphere microbiome mainly at the OTU level which largely attributed to those taxa most strongly depleted by the plant. Thalassiosira pseudonana, which is a centric diatom found in marine environment was observed in this study. This is the first time so far that T. pseudonana is observed in plants rhizosphere and its ability to withstand harsh environmental variation might contribute to the ability of Bambara groundnut to be able to withstand drought, pests and diseases.

plant biology↗

bioRxiv2020

Biochemical and Molecular Characterization, and Bioprospecting of Drought Tolerant Actinomycetes from Maize Rhizosphere Soil

Drought is a major limitation to maize cultivation around the globe. Seven actinomycetes strains were isolated from maize rhizosphere soils in Mahikeng, North-West Province, South Africa. The isolates were biochemically characterized and identified with 16S rRNA gene sequence analysis. Isolates were also screened in vitro for abiotic stress tolerance to different concentrations of NaCl, pH, and polyethylene glycol (PEG 8000), as well as for biosynthesis of drought tolerance genes namely Glutathione peroxidase (GPX), Glycine-rich RNA binding protein (GRP), Desiccation protectant protein (DSP), Guanosine triphosphate binding protein (GTP) and plant growth-promoting genes:1-aminocyclopropane-1-carboxylate deaminase (accd) and siderophore biosynthesis (Sid). About 71.43% of isolates were of the genus Streptomyces (99-100% similarity), while 14.29% belong to the genus Arthrobacter (R15) and 14.29% to the genus Microbacterium (S11) respectively (99% similarity). Five isolates had their optimum growth at 35{degrees}C. Arthrobacter arilaitensis (R15) grew and tolerated 5%, 10%, and 20% PEG at 120 h. Root length increased by 110.53% in PEG treated maize seeds (-0.30 MPa) inoculated with Streptomyces pseudovenezuelae (S20) compared to the un-inoculated control. Likewise, germination percentage and vigor index increased by 37.53% and 194.81% respectively in PEG treated seeds inoculated with S20 than the un-inoculated PEG treated seeds. ACC deaminase gene was amplified in all the isolates, while the gene for siderophore biosynthesis was amplified in 85.71% of the isolates. Genes for the synthesis of GPX, GRP, DSP and GTP were amplified in Arthrobacter arilaitensis (R15) and Streptomyces pseudovenezuelae (S20) which lacked GTP. The amplification of drought-tolerant and plant growth-promoting primers indicates the possible presence of these genes in the isolates. These isolates have the potential for use as bio-inoculants, not only to improve drought tolerance in maize but also to be utilized as biofertilizers and biocontrol agents to facilitate growth promotion.

microbiology↗

bioRxiv2020

BAMBARA GROUNDNUT RHIZOBACTERIA ANTIMICROBIAL AND BIOFERTILIZATION POTENTIAL

Bambara groundnut, an underutilized crop has been proved to be an indigenous crop in Africa with the potential for food security. The rhizosphere of Bambara groundnut like other legumes contains several important bacteria that have not been explored for their plant growth-promoting properties. The aim of this research was to determine the potentials of rhizobacteria from Bambara groundnut soil samples as either biofertilizer or biocontrol agents or both to help provide sustainable agriculture in Africa and globally. Analyses of Bambara groundnut rhizospheric soil samples included chemical analysis such as nitrogen content analysis using extractable inorganic nitrogen method as well as cation exchangeable capacity using ammonium acetate method. Plant growth-promoting properties of isolated rhizobacteria tested include indole acetic acid, hydrogen cyanide, phosphate solubilization, 1-aminocyclopropane-1-carboxylate and ammonia production activities using standard methods. In addition, antifungal assay dual culture method was used to analyze the biocontrol properties of the isolates. Phylogenetic analysis using 16S rRNA was also carried out on the isolates. Isolated rhizobacteria from bambara groundnut rhizosphere were cultured. All the isolates were able to produce ammonia and 1-aminocyclopropane-1-carboxylate while 4.65%, 12.28% and 27.91% produced Hydrogen cyanide, Indole acetic acid and solubilized phosphate respectively, making them important targets as biocontrol and biofertilizer agents. The growth of Fusarium graminearum was suppressed in vitro by 6.98% of the isolates. Plant growth promoting activities of rhizobacteria from bambara groundnut rhizosphere reveals that it has great potentials in food security as biofertilizer and biocontrol agent against fungal and bacterial pathogens.

molecular biology↗