Diverse Metabolite Variations in Tea (Camellia sinensis L.) Leaves Grown Under Various Shade Conditions Revisited: A Metabolomics Study

Abstract

With the increase of tea (Camellia sinensis) consumption, its chemical or metabolite compositions play a crucial role in the determination of tea quality. In general, metabolite compositions of fresh tea leaves including shoots depend on plucking seasons and tea cultivators. Therefore, choosing a specific plucking time of tea leaves can provide use-specified tea products. Artificial control of tea growing, typically shade treatments, can lead to significant changes of the tea metabolite compositions. However, metabolic characteristics of tea grown under various shade treatment conditions remain unclear. Therefore, the objective of the current study was to explore effects of various shade conditions on metabolite compositions of tea through a H NMR-based metabolomics approach. It was noteworthy that the levels of catechins and their derivatives were only influenced at the initial time of shade treatments while most amino acids were upregulated as amounts of shade and periods were increased: that is, the levels of alanine, asparagine, aspartate, isoleucine, threonine, leucine, and valine in fresh tea leaves were conspicuously elevated when shade levels were raised from 90% to 100% and when period of shade treatments was increased by 20 days. Such increased synthesis of amino acids along with large reductions of glucose level reflected carbon starvation under the dark conditions, indicating remarkable proteolysis in the chloroplast of tea leaves. This study provides important information about making amino acid-enhanced tea products based on global characteristics of diverse tea leaf metabolites induced by various shade treatment conditions.

Metabolomic understanding of intrinsic physiology in Panax ginseng during whole growing seasons

“…3D and 3E), concurrently with accumulation of sucrose in roots and leaves (Figs. 7 and S7), as also described in fresh tea ( C. sinensis L.) leaves grown under various shade conditions [35]. These results strongly suggest that levels of ginsenoside compounds in ginseng roots depend on their developments closely linked to seasonal climatic conditions such as sun exposure time and rainfall.…”

“…However, after May, sucrose levels in main and lateral roots were accumulated until September, although such accumulation was not marked. In our previous study, marked accumulation of sucrose has been observed in tea ( Camellia sinensis ) leaves grown under shade or dark conditions because of lack of photosynthesis [35]. In the present study, total sun exposure time started to decrease, whereas total rainfall increased in May (Figs.…”

Stress Responses of Shade-Treated Tea Leaves to High Light Exposure after Removal of Shading

“…In this traditional cultivation method, tea trees are covered with shading nets when new shoots emerge, and they are grown under the shade before being harvested after between 14 and 30 days. During this period, the contents of chlorophylls (Chls) and free amino acids including theanine are increased, and that of catechins is decreased, in the tea shoot [6][7][8][9][10][11]. Tea trees usually produce new shoots thrice in a year from spring to fall in Japanese tea plantations.…”

Characterization of tea leaf metabolites dependent on tea (Camellia sinensis) plant age through 1H NMR-based metabolomics

“…Metabolomics has already unveiled the metabolic profiles of tea leaves (C. sinensis), which were perturbed according to several factors, including plucking positions and seasons, climates, cultivation conditions, and cultivars [11,13,14,22,23]. However, information about the global metabolite differences between tea leaves according to the age of tea plants is very limited.…”

“…Metabolomic approaches have been reported as useful and promising tools to examine the changes in global metabolites of tea plants and potentially provide a better physiological understanding of the biochemical and cellular events [11,12]. For instance, a recent proton nuclear magnetic resonance ( 1 H NMR) based global metabolic profiling study with green tea demonstrated that the tea metabolome was clearly dependent on growing area and hence was influenced by climatic conditions [13].…”