Transcriptome and phytochemical analyses reveal the roles of characteristic metabolites in the taste formation of white tea during the withering process

In the postharvest processing of tea leaves,withering is the first indispensable manufacturing process which produces the mellow,umami and sweet taste of white tea.In this study,we aimed to determine the dynamic changes of the main metabolites and clarify the key differentially expressed genes(DEGs) involved in forming the characteristic taste of white tea during withering.Phytochemical analyses revealed that the contents of total catechins and starch decreased continuously,whereas the contents of theaflavin,γ-aminobutyric acid(GABA),maltose,and soluble sugars increased significantly during withering(from 0–48 h).Meanwhile,the elevation of α-amylase(AMY),β-amylase(BAM),total amylase,and glutamate decarboxylase(GAD) activities may be correlated with the accumulation of GABA and maltose.By transcriptome sequencing,we detected 9 707,15 921,17 353,and 17 538 DEGs at 12,24,36,and 48 h of the withering process,respectively,compared with 0 h sample(fresh leaves).The transcript levels of most of the DEGs involved in catechin biosynthesis were significantly inhibited,whereas those involved in catechin oxidation were significantly up-regulated,which could be correlated to a decrease in catechin content and an increase in theaflavin content.The DEGs involved in GABA biosynthesis were considerably up-regulated,and the down-regulation of SPMS could reduce the competition for converting spermidine to GABA.The up-regulation of the AMY and BAM genes could trigger starch degradation,resulting in the increase of soluble sugar content.These results provide new insights into the importance of the withering process to the characteristic taste of white tea.

Effect of Sunlight Exposure and Different Withering Durations on Theanine Levels in Tea (<i>Camellia sinensis</i>)

Theanine is a non-protein amino acid representing as much as 50% of the total amino acids in black tea and 1% - 2% of dry weight in green tea. It has been shown to be able to reduce high blood pressure, promote relaxation, and inhibit caffeine’s side effects among others. This current study explored the effects of sunlight and withering durations on theanine levels in tea shoots. Theanine content from three leaves and a bud, two leaves and a bud and internodes were detected and quantified by using High Performance Liquid chromatography (HPLC). Sunlight exposure experiment was started at dawn (0600 HRS, GMT + 3.00) when the light intensity was low and tea was collected at three-hour interval throughout the day to (1800 Hrs, GMT + 3.00) when the light intensity had dropped. At the start of the experiment, the theanine levels were significantly high but as the intensity of sunlight increased during the day there was a significant drop in theanine levels, and as the sun set the theanine levels increased significantly again in all samples. The results also showed that theanine levels were significantly increased after 15 hours of withering. Three leaves and a bud withered for 3 hours had mean theanine levels of 1.41% and those withered for 15 hours had mean theanine levels of 3.11%. Internodes exhibited higher mean theanine levels than those of leaves. In the light of these results, it’s evident that withering for a longer period of time and harvesting of tea when the light intensity is low ensure high amount of theanine in tea.

RNA Methylome Reveals the m^(6)A-mediated Regulation of Flavor Metabolites in Tea Leaves under Solar-withering

The epitranscriptomic mark N6-methyladenosine(m^(6)A),which is the predominant internal modification in RNA,is important for plant responses to diverse stresses.Multiple environmental stresses caused by the tea-withering process can greatly influence the accumulation of specialized metabolites and the formation of tea flavor.However,the effects of the m^(6)A-mediated regulatory mechanism on flavor-related metabolic pathways in tea leaves remain relatively uncharacterized.We performed an integrated RNA methylome and transcriptome analysis to explore the m^(6)Amediated regulatory mechanism and its effects on flavonoid and terpenoid metabolism in tea(Camellia sinensis)leaves under solar-withering conditions.Dynamic changes in global m^(6)A level in tea leaves were mainly controlled by two m^(6)A erasers(CsALKBH4A and CsALKBH4B)during solar-withering treatments.Differentially methylated peak-associated genes following solarwithering treatments with different shading rates were assigned to terpenoid biosynthesis and spliceosome pathways.Further analyses indicated that CsALKBH4-driven RNA demethylation can directly affect the accumulation of volatile terpenoids by mediating the stability and abundance of terpenoid biosynthesis-related transcripts and also indirectly influence the flavonoid,catechin,and theaflavin contents by triggering alternative splicing-mediated regulation.Our findings revealed a novel layer of epitranscriptomic gene regulation in tea flavor-related metabolic pathways and established a link between the m^(6)A-mediated regulatory mechanism and the formation of tea flavor under solar-withering conditions.

<i>“Withered Tree” Concept Host</i>, Achieved by Global Contraception and Abortion, Secondary to Fragmented Germ Cells, Agonizingly Reduced Endogenous Estrogen/Androgen, Defaulted Genomic Repertoire, Deranged Cell Metabolism, Metabolic Syndrome, <i>Result in Failure of Pharmacological Therapeutics with Advanced Technologies</i>

Background: In spite of advanced technologies and drug discoveries, morbidity and mortality were undoubtedly increasing in the era of contraception and abortion. Aims: Altruistic correlation of increasing morbidity, mortality, with contraception, abortion was planned for. Methods: In 2012, a retrospective analysis of prevalence of mortality in 350 patients of 20 - 35 years, 35 - 50 years and >50 years from data collected between 2003 and 2012 by convenient, stratified random sampling, from community, hospital, and its association with contraception and abortion status was undertaken;simultaneously, serum estrogen levels obtained from 105 patients were analyzed. In 2014, randomly chosen 8 males, of the 3 age groups, from a different community, whose life partners had undergone sterilization, were assessed for their serum testosterone levels. Results: Contraception users exhibited 3 - 4 fold increased mortality [p 50 years [p < 0.0005]. Endogenous estrogen was reduced in 75% [p < 0.0005] of contraceptive users. Plasma testosterone was reduced in males observing contraception, to less than 50% of normal, e.g. 1.3 ng/ml;66.6% contraception users aged 20 - 35 years had reduced [p < 0.0005] testosterone;100% of male contraception users aged 36 - 70 years showed reduced testosterone [p < 0.0005]. Conclusion: The “withered tree akin host” concept is contraception, abortion, with smashed fragmentation of germ cells. Reduced endogenous estrogen, androgen [dried up, destroyed life factors] result in deranged cell metabolism, cell cycle, and defaulted genomic repertoire, leading to failure of all established pharmacological therapeutics, including advanced technologies which yield gratifying results in non contracepted people today and in every one, before the era of contraception;subsets of people, host with contraception, with destroyed life factors, behave helplessly, concerning therapeutic applications, compared with subsets of people, host without contraception, with intact genomic repertoire, God ordained Life factors, make a remarkable recovery. Contraception reversal replants the germ cells [germ cells destruction stops], hormones rejuvenate to 79.9% of age normal, and diseases abate with recovery.

Wither CIS?

At the turn of the century, when big powers are readjusting their relations, ana-lysts are interested in what role the Commonwealth of Independent States(CIS) will play in an unfolding multipolar world in the forthcoming 21st century.For the moment, however, their attention is focused on the future of the CISitself, an organization committed to integration, yet still plagued with a

IMPACTED BY RIGHT-WING POPULISM, WITHER EUROPEAN INTEGRATION?

2017 is an election year for Europe,also a year on which hinges the destiny of Europe.In view of the general rise of right-wing populist parties in the EU,there have been concerns if another'black swan'would fly out of the general elections of the Netherland,France and Germany.To date,the Dutch and French

定量评估中蒙边境地区不同草原火灾发生区的枯草指数阈值和时空变化

Climate change is manifesting rapidly in the form of fires,droughts,floods,resource scarcity,and species loss,and remains a global risk.Owing to the disaster risk management,there is a need to determine the Dead Fuel Index(DFI)threshold of the fire occurrence area and analyze the spatio-temporal variation of DFI to apply prevention measures efficiently and facilitate sustainable fire risk management.This study used the MODIS Burned Area Monthly L3(MCD64A1),Landsat Global Burned Area(BA)products,and MODIS Surface Reflectance 8-Day L3(MOD09A1)data from 2001 to 2020 to calculate the values of the DFI in the study area before the occurrence of fire.The results showed that:(1)The inversion of the meadow steppe DFI values in the fire area was distributed in the range of 14-26,and the fire rate was the highest in the range of 20-22.The inversion of the typical steppe DFI values in the fire area was distributed in the range of 12-26,and the fire rate was the highest in the range of 16-22.(2)Areas with high fire DFI values included Khalkhgol,Matad,Erdenetsagaan,Bayandun,Gurvanzagal,Dashbalbar in Mongolia,and scattered areas of the Greater Khingan Mountains(forest edge meadow steppe area),East and West Ujumqin Banner,and Xin Barag Right Banner.The highest fire probability of fire occurred during October and April.(3)The DFI values were sensitive to changes in altitude.The results of this study may provide useful information on surface energy balance,grassland carbon storage,soil moisture,grassland health,land desertification,and grazing in the study area,especially for fire risk management.