SUBCELLULAR DISTRIBUTION AND CHEMICAL FORMS OF FLUORIDE IN TEA TREE LEAVES (CAMELLIA SINENSIS L.) AND ITS CELL WALLS

• Published in: Fluoride Vol. 52; no. 3; pp. 385 - 396
• Main Authors: Hu, Na, Fang, Fengxiang, Du, Yaru, Chen, Yuqiong
• Format: Journal Article
• Language: English
• Published: Dunedin International Society for Fluoride Research, Inc 01-07-2019
• Subjects: Adsorption; Aluminum; Cultivars; Environmental science; Fluorides; Fluorine; Trees; Beijing China; United States > US; China
• ISSN: 0015-4725; 2253-4083

Tea tree (Camellia sinensis L.) is an hyper-accumulator of fluorine (F), especially in leaves. Here, the accumulation of different fluorine forms and their subcellular distribution in leaves and cell walls were analyzed in three tea cultivars (Fsensitive Wuniuzao, F-resistant Fudingdabai, and Fuyun No.6). Results indicated that the F content varied significantly in the three cultivars and increased with the maturity of leaves, with most F accumulated in cell walls. Specifically, the greatest amount of F was found in the water-soluble form, about 61.90-87.52% of the total fluorine, followed by the residual-fluorine, about 5.41-27.25%, the organic matter-bound fluorine, about 1.92-8.32%, and, with the lowest proportion, the iron-manganese-bound and exchangeable fluorine. Fluorine in the cell walls was mainly present in the water-soluble form, followed by residual-fluorine. There was a distinct difference between the three different cultivars in F concentration, subcellular distribution, and chemical forms. When compared with the two F-resistant cultivars, the F-sensitive Wuniuzao had higher water soluble F and less residual F in leaves and cell walls. These results suggest that mature leaves are the main F enrichment site, and the retention of F in the cell wall in a bound form might be an important way for tea plants to reduce F toxicity.