Beneath the Surface: Root Metabolites Driving Shoot Agronomic Traits in Tea Plant ( Camellia sinensis L.)

While tea quality traits are largely attributed to leaf-derived metabolites, the role of roots in determining tea (Camellia sinensis L.) productivity and quality has been relatively understudied. Tea roots are central to nitrogen assimilation, carbohydrate storage, and phytohormone biosynthesis, thereby influencing shoot development and environmental responses. Although recent efforts have focused on identifying key genes coordinating quality, yield, and stress resilience, the long lifespan of tea plants limits the practicality of genetic replacement in mature plantations. This review instead emphasizes agronomic and environmental regulation of root metabolites as an alternative approach for enhancing plant performance. Based on the findings (including multiomics studies) about root metabolites and their effects on aboveground traits, we propose a rhizosphere-to-canopy optimization framework incorporating microbiome modulation, nutrient management, and precision agronomy. Root-centered interventions represent a promising, sustainable approach to enhance tea quality, yield, and stress tolerance without replacing established cultivars.