microbiome colonisation in soil
Abstract Microbial colonisation process determines microbial establishment in the plant and soil and influences microbial ability interacting with plant health and productivity. In this study, we hypothesized that colonisation and priority effects influence colonisations of both the biocontrol and pathogens in soils, with effects on plant phenotypes related to plant growth and health. As such, we investigated colonisation of a beneficial bacterium, Burkholderia ambifaria that solubilised phosphate and inhibited the soil-borne pathogen on agar plates via siderophore production. We tested its colonisation in a soil and their colonisation, interaction with the pathogen, and wheat plants in mesocosms, using phenotyping monitoring of plants, global and mesocosm experimental analyses of the bacterial occurrences in soil, combined with amplicon sequencing, qPCR, q(RT)-PCR, as well as rhizosphere metagenomics and metabolomics analyses to reveal the colonisation and changes of plant soil microbiomes, and the underlying driving factors across four time points in 566 samples focusing bacterial, fungal and protist changes. We found that different doses and timing of the treatments (one dose and three doses at sowing) of the bacterial application and priority effects (different order of bacterial and pathogen application) in the soil made differences on wheat plant disease infection and growth. Three times but not one-time bacterial application improved plant growth, and while both one-time and three times beneficial bacterial application significantly reduced pathogen load in the bulk and rhizosphere soil, and effectively controlled disease infection in wheat. We further examined the plant defence gene expression and colonisation of the beneficial bacterium in soil using q(RT)-PCR method, and we found the activation of the plant defence genes by the pathogen, while those with the presence of the bacterium did not demonstrate a priming effect when the pathogen attacked, indicating the benefits were mainly from the direct antagonisms against the pathogen and providing available nutrients for the wheat plants.
Abstract Microbial colonisation process determines microbial establishment in the plant and soil and influences microbial ability interacting with plant health and productivity. In this study, we hypothesized that colonisation and priority effects influence colonisations of both the biocontrol and pathogens in soils, with effects on plant phenotypes related to plant growth and health. As such, we investigated colonisation of a beneficial bacterium, Burkholderia ambifaria that solubilised phosphate and inhibited the soil-borne pathogen on agar plates via siderophore production. We tested its colonisation in a soil and their colonisation, interaction with the pathogen, and wheat plants in mesocosms, using phenotyping monitoring of plants, global and mesocosm experimental analyses of the bacterial occurrences in soil, combined with amplicon sequencing, qPCR, q(RT)-PCR, as well as rhizosphere metagenomics and metabolomics analyses to reveal the colonisation and changes of plant soil microbiomes, and the underlying driving factors across four time points in 566 samples focusing bacterial, fungal and protist changes. We found that different doses and timing of the treatments (one dose and three doses at sowing) of the bacterial application and priority effects (different order of bacterial and pathogen application) in the soil made differences on wheat plant disease infection and growth. Three times but not one-time bacterial application improved plant growth, and while both one-time and three times beneficial bacterial application significantly reduced pathogen load in the bulk and rhizosphere soil, and effectively controlled disease infection in wheat. We further examined the plant defence gene expression and colonisation of the beneficial bacterium in soil using q(RT)-PCR method, and we found the activation of the plant defence genes by the pathogen, while those with the presence of the bacterium did not demonstrate a priming effect when the pathogen attacked, indicating the benefits were mainly from the direct antagonisms against the pathogen and providing available nutrients for the wheat plants.
Hawkesbury Institute for the Environment