Biology subjects

George, T. S.

Publications and source records attributed to George, T. S..

4 recordsLinked to original sources

bioRxiv2025

Evaluation of combined root exudate and rhizosphere microbiota sampling approaches to elucidate plant-soil-microbe interaction

O_LIDeciphering the root exudate-driven interplay between plants and the rhizosphere microbiota is essential for understanding plant adaptation to the environment and future-proofing crop production. However, sampling root exudates and rhizosphere soil remains challenging due to the low throughput and destructive nature of the process. C_LIO_LIWe used the staple crop barley [Hordeum vulgare] as a model to benchmark different sampling approaches for simultaneous exudation and microbiota profiling of soil-grown plants. C_LIO_LIExudate profiles and total dissolved organic carbon exudation rates were consistent across different sampling approaches, whereas root biomass, root morphology measurements, and organic nitrogen exudation varied. C_LIO_LIHigh-throughput amplicon sequencing and quantitative PCR (qPCR) of phylogenetic markers and nitrogen cycle-selected genes revealed a protocol-specific footprint in the composition and abundance of rhizosphere bacterial and fungal microbiota. Yet, on average, 75% of microbes enriched in, and differentiating between, barley rhizosphere and unplanted soil controls were recovered across all the sampling approaches evaluated. C_LIO_LIOur results demonstrated that, under the tested conditions, different sampling approaches produced comparable microbiota and exudation patterns, enabling the integrated study of root exudation and microbial profiles from the same plant. The observed differences across sampling approaches must be considered according to the experimental scope. C_LI

plant biology↗

bioRxiv2021

Smart soils to observe hidden rhizosphere processes

Agriculture must reduce green-house gas emission and pollution, produce safer and healthier food, closer to home, reducing waste whilst delivering more diverse diets to a growing world population. Soils could enable this transformation, but unfortunately, they have a hugely complex and opaque structure and studies of its myriad of mechanisms are difficult. Here, the fabrication of smart soils for the screening of below-ground bio-processes is demonstrated. Particles were generated from fluoropolymer waste with functionalisation converting them into sensors able to report on key chemical dynamics. Tailored functionalization was obtained by radical terpolymerisation to improve growth conditions and sensing capabilities. The study demonstrates the potential for the development of accelerated genetic or agrochemical screens and could pave the way for improved models for rhizosphere dynamics.

plant biology↗

bioRxiv2021

A genome-annotated bacterial collection of the barley rhizosphere microbiota

We generated a bacterial collection from the rhizosphere of cultivated barley (Hordeum vulgare L. ssp. vulgare) to assess taxonomic distribution of culturable members of the barley microbiota and their plant growth-promoting potential. From this we retrieved strains belonging to the dominant phyla of the plant microbiota-- Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria--and gathered evidence they code for functional genes implicated in nitrogen fixation, hydrogen cyanide channels and phosphate solubilisation. Here we present an initial comparative genomic analysis of the collection revealing that plant growth-promoting potential of the culturable barley bacterial microbiota appears to have a relatively broad phylogenetic base while retaining some strain-specificity.

microbiology↗

bioRxiv2021

Whole plant-environment microscopy reveals how Bacillus subtilis utilises the soil pore space to colonise plant roots

Our understanding of plant-microbe interactions in soil is limited by the difficulty of observing processes at the microscopic scale throughout plants large volume of influence. Here, we present the development of 3D live microscopy for resolving plant-microbe interactions across the environment of an entire seedling growing in a transparent soil in tailor-made mesocosms, maintaining physical conditions for the culture of both plants and microorganisms. A tailor made dual-illumination light-sheet system acquired scattering signals from the plant whilst fluorescence signals were captured from transparent soil particles and labelled microorganisms, allowing the generation of quantitative data on samples approximately 3600 mm3 in size with as good as 5 m resolution at a rate of up to one scan every 30 minutes. The system tracked the movement of Bacillus subtilis populations in the rhizosphere of lettuce plants in real time, revealing previously unseen patterns of activity. Motile bacteria favoured small pore spaces over the surface of soil particles, colonising the root in a pulsatile manner. Migrations appeared to be directed towards the root cap, the point "first contact", before subsequent colonisation of mature epidermis cells. Our findings show that microscopes dedicated to live environmental studies present an invaluable tool to understand plant-microbe interactions.

plant biology↗