Research On The Functional Analysis Of Tea Active Components Based On Yeast Deletion Library

Tea is a traditional beverage in China.For thousands of years,tea products have come in a great many types,also,the tea needs of different groups have become more diverse and specific than ever,both thanks to the continuous enrichment of tea tree varieties and the relentless development of tea-making technology.The main problem the tea market faced currently is the contradiction between the over-growing tea resources and the increasing but not yet satisfied demands of tea's function.To resolve this problem,it is necessary to establish an efficient and objective evaluation method of tea's function which could motivate the deep-processed tea product to go through a line of precision development.It is the active components contained in the aqueous extract that determined tea's function,flavor,and shade.Tea polyphenol and catechin,two main functional components of the extract,both have strong pharmacological action and biological activity.Subsequently,the methods now used to evaluate and predict tea's functions are mainly based on instrumental tests or animal experiments,which,are difficult to achieve the market demands for having the new varieties of tea evaluated and analyzed efficiently,due to their certain defects such as difficult to operate and analyze.Based on the yeast deletions library,this experiment identified 340 yeast deletion strains through a high-throughput screen that are sensitive to at least one aqueous extract extracted from four varieties of tea--green tea,black tea,white tea before frosting,or white tea after frosting--65 of which are sensitive to all four aqueous extracts.The GO enrichment analysis of genes corresponding to these 65 yeast deletion strains indicates that they mostly gathered around via actin cytoskeleton assemble,endocytosis,nutriment transportation,etc.Due to certain limitations,after the summarization of deletions corresponded by genes contained in those thoroughfares with relatively high levels,12 deletion strains were selected for further experiment.The deleted yeast genes of those 12 deletion strains form the Arp2/3 complex and the TORC2 complex respectively,both demonstrate a high enrichment multiple levels in enrichment analysis.Gene homology comparison has found some human genes that are of higher homology with the corresponded yeast genes of the 12 selected deletion strains.Those human genes are proven relate to the infiltration,attack,and metastasis abilities of cancer cells by experiments that identify the gene functions and by literature retrieval.Studies also proved that the active components contained in tea,namely,tea polyphenols,L-theanine,epicatechin(EC),and EGCG,could restrain the proliferation of cancer cells.Therefore,by adding tea polyphenols,L-theanine,EC,and EGCG of three different concentration gradients into mediums,observing the growth condition of the yeast's deletions in those special mediums,and then conducting both qualitative and quantitative detection to determine the relationship between the compound concentration and the increment of the yeast deletions,this experiment is trying to establish a new method to evaluate the functions of active components in tea.Both solid and liquid culture were used in the experiment to observe the relationship between the concentration of the four active components and the growth phenotype of the 12 yeast deletion strains under the culture environment.The main purpose of this experiment was to establish a qualitative and quantitative evaluation method for the function of tea active ingredients based on the yeast deletions library.The results elucidate that the content of tea polyphenols in the culture environment is in inverse proportion to the growth phenotype of deletion ARP2?,ARC15?,ARC40?,ARC19?,TOR2?,KOG1?,LST8?,GTR1?,and TSC11?;the content of EC in the culture environment is in inverse proportion to the growth phenotype of deletion ARC40? and ARC19?;the content of EGCG in the culture environment is in inverse proportion to the growth phenotype of deletion ARC40?,ARC19?,KOG1?,and TSC11?;and the content of L-theanine in the culture environment is in inverse proportion to the growth phenotype of deletion ARP2?,ARC15?,ARC40?,ARC19?,TOR2?,KOG1?,LST8?,GTR1?,and TSC11?.In conclusion,yeast deletion ARP2?,ARC15?,ARC40?,ARC19?,TOR2?,KOG1?,LST8?,GTR1?,and TSC11? can be useful to evaluate the function of tea polyphenols,L-theanine,EC,EGCG contained in tea.