Flavonol–Aluminum Complex Formation: Enhancing Aluminum Accumulation in Tea Plants

Polyphenol-rich tea plants are aluminum (Al) accumulators. Whether an association exists between polyphenols and Al accumulation in tea plants remains unclear. This study revealed that the accumulation of the total Al and bound Al contents were both higher in tea samples with high flavonol content than in low, and Al accumulation in tea plants was significantly and positively correlated with their flavonol content. Furthermore, the capability of flavonols combined with Al was higher than that of epigallocatechin gallate (EGCG) and root proanthocyanidins (PAs) under identical conditions. Flavonol–Al complexes signals (94 ppm) were detected in the tender roots and old leaves of tea plants through solid-state 27Al nuclear magnetic resonance (NMR) imaging, and the strength of the signals in the high flavonol content tea samples was considerably stronger than that in the low flavonol content tea samples. This study provides a new perspective for studying Al accumulation in different tea varieties.富多酚茶树属于铝（Aluminum）富集型植物。目前尚不清楚茶树体内多酚与铝富集之间是否存在关联。本研究发现，黄酮醇（flavonol）含量较高的茶树样品中，总铝与结合态铝的含量均高于黄酮醇含量较低的样品；且茶树体内的铝富集量与黄酮醇含量呈显著正相关。此外，在相同条件下，黄酮醇与铝的结合能力高于表没食子儿茶素没食子酸酯（epigallocatechin gallate, EGCG）与根原花青素（proanthocyanidins, PAs）。通过固态27Al核磁共振（nuclear magnetic resonance, NMR）成像技术，研究人员在茶树幼根与老叶中检测到了黄酮醇-铝复合物信号（94 ppm），且黄酮醇含量较高的茶树样品的信号强度显著高于黄酮醇含量较低的样品。本研究为不同茶树品种的铝富集研究提供了全新视角。