Effects Of Red And Blue Light On The Growth And Metabolites Of Tea

light is the main meteorological factor affecting the growth,development and material metabolism of tea plants.Light quality and intensity have an important influence on the formation of leaf morphology and quality components of young shoots.In order to investigate the effects of red and blue light on the growth and metabolites of tea leaves,Fujian-Suixian was used as the test material in this study.The blue light(450nm,50μmol·m^-2·s^-1,100μmol·m^-2·s^-1,200μmol·m^-2·s^-1)and red light(660nm,120μmol·m^-2·s^-1,240μmol·m^-2·s^-1,480μmol·m^-2·s^-1)were used in the experiment for 35 days,the effects of red and blue light on the growth of tea shoots were studied by analyzing the leaf morphology and chlorophyll fluorescence parameters.The method of AQC derivatization combined with liquid chromatography-mass spectrometry was used to establish and optimize the determination of free amino acids in tea.The contents of 35kinds of amino acids in tea were determined.The effects of red and blue light treatment on the contents of amino acids and metabolites in tea were analyzed.The main results are as follows:1.The effect of red and blue light treatment on the growth of tea leavesIn this study,the morphological characteristics of tea shoots treated with different light intensity red and blue light were investigated.The results showed that the effects of different light intensity blue light on the growth of tea shoots were 200μmol·m^-2·s^-1,100μmol·m^-2·s^-1,50μmol·m^-2·s^-1,respectively.The effects of red light on the growth of tea shoots were 480μmol·m^-2·s^-1,240μmol·m^-2·s^-1and 120μmol·m^-2·s^-1.The red and blue light treatment had little effect on the thickness of tea shoots.The blue light treatment was beneficial to the growth of the thickness of tea shoots,while the red light treatment of 240μmol·m^-2·s^-1 andμmol·m^-2·s^-1inhibited the thickness of tea shoots.The results showed that with the increase of red and blue light,the values of F₀,NPQ,F_v/F_m,F_v/F₀ and q P decreased,indicating that the excessive red and blue light would weaken the potential photosynthetic capacity of tea leaves,reduce the photochemical reaction and cause the photoinhibition of tea leaves.2.Establishment,optimization and application of determination method of free amino acids in teaIn this study,AQC derivatization liquid chromatography-mass spectrometry was used to determine 35 kinds of free amino acids in 20minutes,showing a good linear relationship.The correlation coefficient of each regression equation was greater than 0.9902,the quantitative limitmg/L,and the daily reproducibility of various amino acids was less than4.6%.The recoveries were 81.0%～99.9%,RSD was less than 9.5%.This method can meet the requirements of quantitative analysis of amino acid components,has reliable accuracy and precision,and can be used to detect the content of amino acids in tea.The amino acid composition characteristics of six tea groups and different grades of white peony were statistically analyzed.The results showed that the amino acid composition of green tea and yellow tea were similar,and the amino acid composition of other tea groups showed their own characteristics.The amino acid composition characteristics of different grades of white peony tea were statistically analyzed.The free amino acid composition of three grades of white peony tea was closely related to its quality grade,which could provide basic reference for the scientific evaluation of taste composition and quality grade of white peony tea.3.Effects effect of red and blue light treatment on the main metabolites of tea shootsIn this study,tea trees were irradiated with different intensities of red and blue light,and the shoots of tea trees were collected to determine the composition of free amino acids.The results showed that a total of 28kinds of amino acids（including:Alanine,L-α-Aminoadipic Acid,D,L-β-Aminoisobutyric Acid,γ-Amino-n-butyric Acid,Arginine,Aspartic Acid,Citrulline,Hydroxy-L-proline,Glutamic Acid,Glycine,Histidine,Hydroxylysine,Isoleucine,Leucine,Lysine,Methionine,Ornithine,Phenylalanine,Proline,Sarcosine,Serine,Threonine,Tryptophan,Tyrosine,Valine,Pipecolic Acid,Asparagine,Theanine,Glutamine）were detected.Among them,the contents of theanine,glutamic acid,glutamine and asparagine were greatly affected by the red and blue light intensity and irradiation time.Specifically,when the red light intensity was 480μmol·m^-2·s^-1 and the irradiation time was 14 days,the contents of theanine,glutamate,glutamine and asparagine were significantly higher than those of the control group,but there was no significant correlation between arginine content and red and blue light.In addition,the content of glutamine reached the highest level on the 14th day under red light irradiation of 240μmol·m^-2·s^-1,and theanine content reached the highest level on the 14th day under red light irradiation of 480μmol·m^-2·s^-1,which was significantly higher than that of other treatments.The catechins and alkaloids in the young shoots of tea trees were inhibited by the supplement of red light and different light intensity.The catechins and alkaloids were higher in the treatment of 50μmol·m^-2·s^-1blue light for21 days.From the point of view of the taste of the above amino acids,because theanine is fresh and sweet,glutamine and aspartic acid are sweet and sour,and arginine is bitter,so the content of the above amino acids should be positively correlated with the quality of tea.Red light treatment with specific intensity is beneficial to improve the taste quality of fresh tea leaves.4.Effect of red and blue light on metabolome of tea shootsIn this study,405 nonvolatile compounds were detected in fresh tea leaves,including 200 lipid and lipid molecules,61 phenylpropionic acid and polyketone,44 organic oxygen compounds,35 organic acids and their derivatives,33 organic heterocyclic compounds,14 benzene ring compounds,7 nucleosides,nucleotides and analogues,4 organic nitrogen compounds,4 organotin compounds,1 lignan,1 neolignan and related compounds,1 organic compound and 1 organometallic compound.48different metabolites were identified under different blue light intensities,and 30 different metabolites were identified under different red light intensities.Red and blue light treatments affect the content of amino acids,lipids,phenylpropionic acid and polyketone,as well as a small amount of carbohydrates and their conjugates,nucleotides and amino acids and their derivatives in tea shoots.The content of some flavonoids,lipids and lipid molecules increased when treated with 240μmol·m^-2·s^-1 red light and 200μmol·m^-2·s^-1 blue ligh.