Tag Archive for 'Theanine'

A proposed model for CsMYB73 negatively regulating the accumulation of theanine mediated by CsGGT2 and CsGGT4 in tea shoots of ‘Huangkui’ returning green from yellow. The blue arrows indicate theanine metabolism involved in CsGGT2. The orange arrows indicate the theanine metabolism involved in CsGGT4. The black arrows represent upregulated and downregulated gene expression and theanine content. The gray arrows represent a positive effect, and the gray vertical lines represent an inhibitory effect. Glu - glutamine; CsGGT2 and CsGGT4 - γ-glutamyl-transpeptidase from tea plants; CsMYB73 - transcription factor from tea plants. Ellipses embedded with question marks represent unverified regulatory factors that may participate in this model. During the yellowing period of ‘Huangkui’ leaves, a significant suppression of CsMYB73 further inhibited the theanine hydrolase CsGGT2 activity, and activated the theanine synthase CsGGT4 activity, resulting in a higher level of theanine accumulated in tea shoots. As tea shoots transition from yellow to green, the upregulation of CsMYB73 leads to an enhancement in the activity of theanine hydrolase CsGGT2, while simultaneously suppressing the synthesis of theanine by the theanine synthase CsGGT4. Consequently, this process culminates in a persistent reduction in the accumulation level of theanine in ‘Huangkui’ shoots. Image credit: Chang et al., doi: 10.1093/hr/uhae012.

New Study Provides Insights into Theanine Metabolism in Tea Plants

Feb 11, 2025 by News Staff

The metabolism of theanine — a unique non-proteinogenic amino acid — is a necessary biological process during the planting and production of...

By analyzing the variation of FAAs among 339 tea accessions in two years, we can know that the determined components of FAAs including arginine, glutamine, glutamate, alanine, and theanine with the highest diversity index differed among different genetic resources and intraspecific accessions. Meanwhile, their amounts in Camellia sinensis were all significantly higher than in the wild relatives. The study confirmed the significant opposite trend between chlorophyll and FAA profiles. Image credit: Sci.News.

New Research Sheds More Light on Genetic Makeup of Tea

Dec 26, 2024 by News Staff

Free amino acids (FAAs) positively determine the tea quality, notably theanine, endowing umami taste of tea infusion. However, their concentrations vary...

A working model for nitrogen assimilation, amino acid synthesis, transport, and degradation/recycling in tea plants. Image credit: Yu et al., doi: 10.1093/hr/uhae060.

Study Provides New Insights into Metabolism and Transport of Amino Acids in Tea Plants

Jun 24, 2024 by News Staff

High levels of free amino acids in tea leaves are crucial for tea flavor and health function. However, biosynthesis, transport, and turnover of amino acids...