Unveiling the secret of a better cup of tea: The role of root microbes

Researchers from Fujian Agriculture and Forestry University in China have unveiled a surprising secret to enhancing the flavor and quality of tea: the microbial communities residing on tea roots.

Lead researcher Tongda Xu explains, “Significant disparities in microbial communities, particularly nitrogen metabolism-related microorganisms, were identified in the roots of tea plants with varying qualities through microbiomics. Crucially, through the isolation and assembly of a synthetic microbial community from high-quality tea plant roots, we managed to notably enhance the amino acid content in various tea plant varieties, resulting in an improvement in tea quality.”

The study, published in the journal Current Biology, sheds light on the crucial role of root microbes in the production of high-quality tea. By altering the microbial composition on tea roots, the researchers were able to enhance the amino acid content, ultimately improving the taste and quality of the tea.

The researchers constructed a synthetic microbial community, known as SynCom, which closely mirrored the microbial composition found in association with a high-theanine tea variety called Rougui. When applied to tea roots, SynCom boosted theanine levels, showcasing its potential to enhance tea quality.

Co-author Wenxin Tang shares, “The initial expectation for the synthetic microbial community derived from high-quality tea plant roots was to enhance the quality of low-quality tea plants. However, to our astonishment, we discovered that the synthetic microbial community not only enhances the quality of low-quality tea plants but also exerts a significant promoting effect on certain high-quality tea varieties. Furthermore, this effect is particularly pronounced in low-nitrogen soil conditions.”

These findings hold promise for the future of tea production and agriculture as a whole. The researchers believe that synthetically produced microbial communities could not only improve tea quality, especially in nitrogen-deficient soil conditions, but also reduce the need for chemical fertilizers. Moreover, the study suggests that this breakthrough could have far-reaching implications for other agricultural crops.

Xu emphasises, “Based on our current experimental findings, the inclusion of the SynCom21 microbial community has not only improved the absorption of ammonium nitrogen in different tea varieties but also enhanced the uptake of ammonium nitrogen in Arabidopsis thaliana. This suggests that the ammonium nitrogen uptake-promoting function of SynCom21 may be applicable to various plants, including other crops.”

The implications of this research extend beyond tea production, as the potential to improve the quality of other crops, such as rice with greater protein content, is on the horizon. The team plans to further optimize SynCom and assess its utilization in field trials, with the aim of unraveling the full extent of how root microbes can affect other secondary metabolites in tea trees.