Tea is the second most consumed drink in the world, after water. There are many types of teas, depending on their oxidation levels: green, yellow, oolong and black. Well-known varieties of black tea include Darjeeling, Assam, Turkish and Ceylon teas. In 2016, Turkey was the largest tea-consuming country in the world, with a per capita tea consumption of approximately 6.96 pounds per year. In contrast, China had an annual consumption of 1.25 pounds per person. Recent research published in the journal Current Biology has revealed that the complex flavor of a quality cup of tea does not solely depend on the tea varieties used to make it. Instead, it is influenced by another crucial factor: the collection of microbes found on tea roots. The study showed that by altering this microbial community, it is possible to improve the quality of the tea even further.
“Significant disparities in microbial communities, particularly nitrogen metabolism-related microorganisms, were identified in the roots of tea plants with varying qualities through microbiomics,” says Tongda Xu of Fujian Agriculture and Forestry University in Fujian, China. “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.”
China has a vast collection of genetic resources for tea cultivation, but improving the quality of tea through genetic breeding methods poses a significant challenge. Researchers are exploring alternative ways to modify and enhance tea, including the use of microbial agents. Earlier studies have shown that soil microbes living in plant roots can influence nutrient uptake and utilization by plants. In a new study, researchers aimed to understand better how root microbes impact tea quality.
They discovered that root microbes affect tea’s uptake of ammonia, which, in turn, influences the production of theanine, the primary determinant of tea taste. They also found that different teas have varying microbe populations. By comparing teas with different theanine levels, they identified a promising set of microbes that could alter nitrogen metabolism and increase theanine levels.
The researchers created a synthetic microbial community, called SynCom, which closely replicated the one found in high-theanine tea variety, Rougui. When they applied SynCom to tea roots, they found that it boosted theanine levels. Additionally, the microbes enabled Arabidopsis thaliana, a plant commonly used in biological studies, to withstand low nitrogen conditions.
The study’s findings could have broad implications for agriculture and the tea industry.
“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,” says study co-author Wenxin Tang. “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.”
According to the study, artificially cultivated microbial communities could enhance the quality of teas, particularly when grown in soil that lacks nitrogen. Tea trees demand a high amount of nitrogen, and this discovery could aid in decreasing the usage of chemical fertilizers while simultaneously enhancing the tea tree’s quality. The findings could have significant implications for agricultural crops in general.
“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,” Xu says. “This suggests that the ammonium nitrogen uptake-promoting function of SynCom21 may be applicable to various plants, including other crops.”
According to experts, SynCom has the potential to enhance the quality of rice by increasing its protein content. The researchers intend to continue refining SynCom and test its effectiveness through field trials. Moreover, they aim to investigate how root microbes impact other secondary metabolites in tea trees.
This news is a creative derivative product from articles published in famous peer-reviewed journals and Govt reports:
References:
1. Xin, W., Zhang, J., Yu, Y., Tian, Y., Li, H., Chen, X., … & Tang, W. (2024). Root microbiota of tea plants regulate nitrogen homeostasis and theanine synthesis to influence tea quality. Current Biology. DOI: 10.1016/j.cub.2024.01.044
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6. https://www.statista.com/statistics/940102/global-tea-consumption/#:~:text=This%20statistic%20shows%20the%20annual,7.4%20billion%20kilograms%20by%202025.&text=Tea%20is%20the%20second%20most,in%20the%20world%2C%20after%20water