Effect And Mechanism Of Reproductive Growth Of Tea Plants On The Formation Of Tea Quality Components

Tea plants have the characteristics of long flowering period and large flowering volume in production.Vigorous reproductive growth consumes a large amount of nutrients,resulting in the inhibition of the vegetative growth of leaves,reduced yield,and decreased quality.However,the metabolic process and regulatory mechanism that affected the formation of tea quality components in the reproductive growth of tea plants are currently unclear.In this study,different varieties of tea plants were used to obtain tea plants with different reproductive growth levels through formula fertilization and flower picking.By analyzed their nutrient status,quality components content,carbohydrate and anthocyanin components,and combined transcriptome sequencing and other methods,the impact mechanism of different flowering levels on the growth of tea trees was preliminarily explained.The main results are listed as below:1.Blooming significantly changes the carbon metabolism process of tea plants,inhibits the accumulation of tea polyphenols,and reduces the content of nitrogen compounds such as total nitrogen and amino acids in tea plants.It is worth noting that a large amount of flowering can reduce the anthocyanin content,leading to the color turning green of purple tea leaves: mainly concentrated in the conversion of colorless anthocyanins to anthocyanins,which combine with a glucoside to form anthocyanin-3-Oglucoside at the third position.Further glycosylation,methylation,and other anthocyanins can be formed on anthocyanin-3-O-glucoside.2.Massive flowering can also delay the germination of new shoots in the following year,altering the content of carbohydrates.Flowering led to the decrease of fructose,glucose and galactose content,but the increase of sucrose content.3.Increasing the proportion of potassium and nitrogen fertilizers can effectively inhibit the reproductive growth of tea trees,leading to a decrease in flowering volume,while increasing the proportion of phosphorus fertilizers can promote the reproductive growth of tea trees.In addition,under the same fertilization treatment,the flowering rate of tea trees with leaf color variation is higher than that of normal green varieties,indicating that there are variety differences in the response of tea tree reproductive growth to nutrients.4.The flowering amount of tea trees is positively correlated with carbon content,and negatively correlated with nitrogen and potassium content.Potassium may regulate the carbon metabolism process in tea plants,inhibit carbon metabolism levels,reduce tea polyphenol content,and thus inhibit tea flowering.Nitrogen can enhance nitrogen metabolism and inhibit reproductive growth.Reproductive growth consumes a large amount of plant nutrients,leading to weakened growth potential.The above results indicate that nutrients affect the reproductive growth of tea trees from multiple perspectives.5.The transcriptome data showed that the anthocyanin-3-Oglucosyltransferase related genes CSS0047476 and CSS0014534 were significantly up-regulated after the removal of flower buds in tea plants,which was consistent with the changes in the contents of pelargonin 3-Oglucoside,cyanidin 3-O-glucoside and delphinidin 3-O-glucoside.After the removal of flower buds,tea trees induce anthocyanin-3-Oglucosyltransferase to catalyze the conversion of geranium-3-O-glucoside,cornflower 3-O-glucoside,and delphinidin 3-O-glucoside from geranium-3-O-glucoside,cornflower 3-O-glucoside,and delphinidin 3-O-glucoside,leading to the formation of more anthocyanin like substances,resulting in an increase in anthocyanin content and a purple leaf color.