Effect Of The Main Environmental Factors On Anthocyanin Content And Related Genes Expression Of Purple Tea Shoots

Purple tea shoots usually occur in clony variety tea plantation, especially in spring and fall. Purple tea shoots contain about0.5%to1.0%anthocyanins in dry weight, which are much higher than the green shoots. Studies have shown that the primary cause of tea shoots purpled is the high content of anthocyanin.The accumulation of plant anthocyanin is not only influenced by genetic background differences, but also influenced by light, temperature and nitrogen. In view of the universality of purple shoots occurring in tea production, and the impact on the tea processing property and quality about anthocyanin accumulation, so it has important practical significance and extensive use value for studying regulatory mechanisms of environmental factors on the formation of purple shoots.This paper selects three-year-old varieties of Jiukengzhong as material for nitrogen, temperature and illumination treatments. The effects of nitrogen, temperature and illumination for purple tea shoots regulation mechanism were studied by Gene Expression, enzymatic analysis and effective components testing. The basis can control the formation of purple tea shoots with cultivation techniques and provides the theoretical basis of directional breeding. The main results were as follows:1.Light is one of the main environmental factors affecting anthocyanin coloration, light quality and light intensity can affect the plant anthocyanin synthesis to some extent. The reduction of light intensity will inhibit the expression of key enzyme genes in the metabolism of tea anthocyanin and reduce anthocyanin accumulation. Ultraviolet is the most effective element that induces plant anthocyanin accumulation, which plays a positive role in the regulation of anthocyanin key genes CHS, CHI, F3H, DFR, ANS ANRexpression,. Blue and red differently regulat the expression of key enzyme genes, research shows that red light can regulate the expression of ANS, and CHI、ANR are insensitive to the regulation response about those two lights.2.Low temperature treatment can promote the expression of key genes of anthocyanin synthesis, which is conducive to the anthocyanin accumulation in tea shoots. The temperature that is too high or too low both will inhibit the synthesis of tea anthocyanin gene expression of key enzymes, and reduce the synthesis of tea shoots anthocyanin. Under T2(10℃/20℃) treatment, CHS, CHI, F3H, DFR, ANS, ANR highest expression, under treatment at T2,T1(5℃/15℃)F3H and overexpress which are downstream of the structural gene, As the temperature increases, compared with T2treatment, expression levels of CHS, CHI, F3H, ANS, ANR structural genes show a downward trend under T3, T4, T5treatment, F3H and expression are significantly reduced.3.Nitrogen deficiency induces anthocyanin biosynthesis structural genes upregulated, The expression levels of tea shoots anthocyanin biosynthesis structural genes CHS, CHI, F3H, ANS are significantly upregulated and the activity of key enzyme increases, the expression of ANR downward, the rate of synthesis anthocyanin increased but reduction rate decreased. Thus, he accumulation of anthocyanin increases in the tea shoots and causes this phenomenon of purple tea shoots occur.4.Under different treatment, the accumulation mode biochemical compositions in tea tree bud leaf is different. Light intensity is abate, which reduces the amounts of carbon material (tea polyphenols, catechins, flavonoids, cyanine glycosides) and increases the amounts of nmaterial amino acids and caffeine). Red and orange light is good at tea tree bud leaves the accumulation of carbon material. T2(10℃/20℃)processing, cyanine glycosides, tea polyphenols, catechins has the highest accumulation, T5(25℃/35℃), the highest accumulation of flavonoids. In addition, with the loss of the temperature, the amounts of the amino acid and caffeine levels reduce. Nitrogen deficiency treatment inhibited the tea tree in bud leaf nitrogen accumulation of class material, improving the carbon material accumulation of a class.5.Under different densities the variation tendency of the key enzyme activity in anthocyanin metabolic pathway in the bud and leaveof the tea is different, light treatment F3H(flavanone3-hydroxylase)、DFR(2-hydroxy flavonols reductase)、ANS(cyanine nucleoside synthetase) agrees with its trend of regulation of gene expression.In addition to the ANS. under the different temperature treatment, the change of the key enzyme activity in anthocyanin metabolic pathway is inconsistent with the regulation pattern of its related genes. The activity change of CHI、F3H、DFR、ANS、ANR agrees with the regulation pattern of its related genes under nitrogen deficient-condition.