Metabolic analyses reveal growth characteristics of young tea shoots in spring

Abstract

Abstract Tea plant (Camellia sinensis L.) is one of the three leading crop sources of non-alcoholic commercial beverages around the world. It is harvested for its young shoots and steeped into tea infusion. To reveal the metabolic characteristics of young tea shoots growing in early spring, we conducted metabolite profiling of different shoot tissues using gas chromatography–mass spectrometry and ultra-high performance liquid chromatography–tandem mass spectrometry. Metabolic profiling indicated that different tissues varied widely mainly in levels of organic acids, flavonoids, amino acids, polyols and sugars. The results suggested that the buds needed more energy and amino acids for chloroplasts’ biogenesis and expansion. The leaves accumulated large amounts of tryptophan and indoleacrylic acid, which contributed to leaf growth. They also accumulated sugars, sugar alcohols and flavonoids that contributed to tea quality. The stems accumulated gibberellin A14, l -theanine, pyroglutamic acid, 4-aminobutyric acid and glutamine, which may promote stem elongation; and stem accumulation of quinic and shikimic acids contributed to stem lignification. This study showed metabolic characteristics of tea shoot growth in spring, and revealed that different parts of the young shoot may specifically rely on tissue-specific metabolites for their growth.