Regulative Mechanism Of Light On Anthocyanin Synthesis And Metabolism Of Betula Royal Frost Leaves

Betula Royal Frost is a kind of hybrid and belongs to the Betulaceae Betula. Its latin name is Betula populifolia ’Whitespire’× B.’Crimson Frost’. It is a kind of ornamental tree of deciduous broad leaved tree species. As it was introduced from abroad, we found that the leaf color of purple-leaf seedlings was not stable after introduction, and it could be affected by illumination. So the synthesis and metabolism of anthocyanin, an important pigment for leaf coloring, were regulated by light. In this study, purple-leaf seedlings was research objects and green seedlings was reference objects. We researched the physiological mechanism of that light regulated anthocyanin synthetic pathway by comparing the contents of anthocyanin and the levels of parameters which were related with anthocyanin synthetic pathway, such as reducing sugar and so on, under different light qualities, light intensities and photoperiods. The main research results as followed:1.In light qualitative experiments, the base diameter growth, maximum net photosynthetic rates, photosynthetic parameters such as light compensation points, anthocyanin contents, reducing sugar contents, and enzyme activities of PAL, CHI, DFR, F3H of purple-leaf seedlings under white light were significantly higher than other treatments; red light is significantly promoted the chlorophyll and ABA contents increased; blue light had the most significant effect on seedling growth; reducing sugars, PAL, CHI, DFR, F3H and net photosynthetic rate (Pn) of leaves would accelerate the synthesis of anthocyanin, while chlorophyll and ABA had the opposite effects in the regulation process of light quality.2.In light intensity experiments, strong illumination significantly promoted the growth of seedlings and increased anthocyanin contents, reducing sugar contents the activities of PAL, CHI and DFR and the levels of photosynthetic parameters such as the maximum net photosynthetic rates and so on; while weak illumination promoted chlorophyll and ABA contents increased; the regulation of light intensity was finished by the positive effects of reducing sugars, Pn,PAL, CHI and DFR, and the negative effects of chlorophyll.3.Photoperiod had significant effects on the maximum net photosynthetic rates of purple-leaf seedling leaves, while the effects on were not significant; long photoperiod could significantly increase the contents of anthocyanin, chlorophyll, reducing sugar and ABA; short photoperiod significantly improved the enzyme activities of PAL, CHI, DFR, F3H; In the determination of parameters, is only photoperiod of anthocyanin synthesis control mainly through promote the synthesis of chlorophyll and Pn. Within all of the determined parameters, only chlorophyll and Pn took part in the process of anthocyanin synthesis regulated by photoperiod.So we knowed that reducing sugar, PAL, CHI, DFR, F3H and net photosynthetic rate could accelerate anthocyanin synthesis, while chlorophyll and ABA inhibited the process under different light qualities; reducing sugar, PAL, CHI, DFR and net photosynthetic rate could accelerate anthocyanin synthesis, while chlorophyll made opposite effect under different light intensities; only chlorophyll and net photosynthetic rate showed positive correlation with the content of anthocyanin under different photoperiod. The results could provide the theory basis for the establishment of the technique which could keep leaf color stable and provide reference for the study of anthocyanin synthetic mechanism at the same time.