# Tea Cultivar Genotype Shapes Rhizosphere Microbiome Assembly Through Metabolic Differentiation

## TL;DR

Tea plant genetics influence soil microbes through chemical differences, offering insights for better tea cultivation.

## Contribution

This study reveals how tea cultivar genotypes shape rhizosphere microbiomes via metabolic differentiation.

## Key findings

- Rhizosphere metabolites explained significant variation in bacterial and fungal community structures.
- Tea cultivars showed distinct microbial communities linked to organic acids, fatty acids, and carbohydrates.
- Arbuscular mycorrhizal fungi were abundant in low-fertilizer systems but nearly absent in conventional ones.

## Abstract

Tea cultivar genotype plays a critical role in shaping rhizosphere microbiome assembly, yet the underlying mechanisms remain poorly understood. This study employed a controlled pot experiment with five widely cultivated Chinese tea cultivars (Camellia sinensis) to investigate how cultivar-specific variation influences rhizosphere microbial communities and their assembly processes. Rhizosphere soil microbiomes (bacterial and fungal communities) and metabolomes were characterized using 16S rRNA and ITS2 amplicon sequencing combined with untargeted metabolomics. Significant differences in rhizosphere metabolite composition, primarily organic acids, fatty acids, and carbohydrates, were observed among cultivars, which corresponded to distinct bacterial and fungal community structures. Redundancy analysis (RDA) revealed that rhizosphere metabolites explained 19.87% of bacterial and 21.63% of fungal community compositional variation, second only to soil physicochemical properties. Neutral community model and modified stochasticity ratio analyses indicated that microbial assembly across cultivars was predominantly deterministic, and rhizosphere metabolite profiles were strongly correlated with microbial community structure. Notably, arbuscular mycorrhizal fungi made up about 11% of the fungal communities in minimally fertilized pot systems, contrasting sharply with their near-absence in conventionally managed systems plantations. These findings demonstrate that tea cultivar genotype significantly shapes rhizosphere microbiome assembly through metabolic differentiation, providing a theoretical foundation for integrating microbiome considerations into tea breeding programs and developing cultivar-specific management strategies.