title: Developmental changes in carbon and nitrogen metabolism affect tea quality in different leaf position.
abstract: Leaf position represents a specific developmental stage that influences both photosynthesis and respiration. However, the precise relationships between photosynthesis and respiration in different leaf position that affect tea quality are largely unknown. Here, we show that the effective quantum yield of photosystem II [ΦPSⅡ] as well as total chlorophyll concentration (TChl) of tea leaves increased gradually with leaf maturity. Moreover, respiration rate (RR) together with total nitrogen concentration (TN) decreased persistently, but total carbon remained unchanged during leaf maturation. Analyses of major N-based organic compounds revealed that decrease in TN was attributed to a significant decrease in the concentration of caffeine and amino acids (AA) in mature leaves. Furthermore, soluble sugar (SS) decreased, but starch concentration increased with leaf maturity, indicating that source-sink relationship was altered during tea leaf development. Detailed correlation analysis showed that ΦPSⅡ was negatively correlated with RR, SS, starch, tea polyphenol (TP), total catechins and TN, but positively correlated with TChl; while RR was positively correlated with TN, SS, TP and caffeine, but negatively correlated with TChl and starch concentrations. Our results suggest that biosynthesis of chlorophyll, catechins and polyphenols is closely associated with photosynthesis and respiration in different leaf position that greatly influences the relationship between primary and secondary metabolism in tea plants.
authors.affiliation: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, PR China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing, PR China.
authors.forename: Zhi-Xin
authors.initials: ZX
authors.lastname: Li
authors.affiliation: School of Biotechnology and Food Science, Anyang Institute of Technology, Anyang, 455000, PR China.
authors.forename: Wei-Jun
authors.initials: WJ
authors.lastname: Yang
authors.affiliation: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, PR China; Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Institute of Vegetable Science, Zhejiang University, Hangzhou, 310058, PR China.
authors.forename: Golam Jalal
authors.initials: GJ
authors.lastname: Ahammed
authors.affiliation: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, PR China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing, PR China.
authors.forename: Chen
authors.initials: C
authors.lastname: Shen
authors.affiliation: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Yan
authors.affiliation: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, PR China. Electronic address: lixin@tricaas.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, Tea Research Institute, Chinese Academy of Agricultural Sciences, 9 Meiling Road, Hangzhou, 310008, PR China. Electronic address: hanwy@tricaas.com.
authors.forename: Wen-Yan
authors.initials: WY
authors.lastname: Han
mesh_terms: D000596:Amino Acids / Q000032:analysis; D053898:Biosynthetic Pathways; D002110:Caffeine / Q000032:analysis; D028241:Camellia sinensis / Q000254:growth & development* / Q000378:metabolism*; D002241:Carbohydrates / Q000032:analysis; D002244:Carbon / Q000378:metabolism*; D002392:Catechin / Q000032:analysis; D019069:Cell Respiration; D002734:Chlorophyll / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000378:metabolism*; D059808:Polyphenols / Q000378:metabolism; D012995:Solubility; D013213:Starch / Q000378:metabolism
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D045332:Photosystem II Protein Complex; D059808:Polyphenols; D002734:Chlorophyll; D002110:Caffeine; D002244:Carbon; D002392:Catechin; D013213:Starch; D009584:Nitrogen
keywords: Amino acids; Caffeine; Camellia sinensis; Leaf position; Photosynthesis; Respiration; Tea polyphenol