The Effect Of Light On Biosynthesis And Gene Expression Level Of Alkaloids In Catharanthus Roseus

There are many environmental factors play a key role in growth and development of plants that one of which is light and many ways on light regulate to plants’ growth and development; plant morphology, photosynthesis and photoperiod. The lack of assimilate will relate to the plant not strong and sugar content also decreased, the yield will be greatly decreased. Especially when the plants below the light compensation point, the accumulation of photosynthetic products will become less even zero. All this has seriously hampered the normal growth of plants, which are explained photosynthetic products play a key role for the plant, the plant can not be separated from photosynthetic products.Use of the environment to control the secondary metabolism of plants has been the concern of people, at the same time, a large number of studies have reported the effects of light on the secondary metabolism of plants.but a series of experimental studies on the effects of light on the secondary metabolites and genes were still a minority.In this paper, we used the seedling of Catharanthus roseus from Hainan as the experimental material and perlite as the matrix. We summarize the progress in response to the impact on seed germination by setting different light intensity conditions for comparison. We also describe the light on the growth and metabolism of Catharanthus roseus seed germination and plant to provide a scientific basis for the change of light on plant secondary metabolites. The results are as follows:The biomass of root, stem and leaf increased with the increasing of light intensity.The contect of vindoline, catharanthine, vinblastine and tabersonine in medium light have reached the highest in leaves. Vincristine increased as the light intensity decreases and reached highest in the low light, but the increased rate weakened. Contrary to the trend to vincristine, serpentine reached highest and the content decreased with the light intensity weakened, the content reached minimum in low light. Vinblastine, vincristine, and tabersonine reached the highest value under the medium light in roots.The content of vinblastine increases as the light intensity decreases, then decreases rapidly, these all related to the response of CPR and PRX; the trend of vincristine is opposite to vinblastine; Tabersonine in low light was the smallest, and it is proportional to the expression of STR and SGD in root, it is indicated that STR and SGD participate and promote the synthesis of tabersonine; A series of changes in gene expression have a certain promotion or inhibition to the synthesis of alkaloids. The content of D4H with the change of light intensity has great fluctuation, with the intensity reduced, the contents of D4H decreased and the content of vindoline synthesis has greatly changed. The trend of T16H changed are more similar with vindoline, it is beneficial to the expression of strong light;In the downstream gene, the DAT content was increased, which indicated that the gene was expressed in low light condition. CPR and DXS have a clear response to the effects of light and their expression changes regularly. All of these showed that they were able to respond positively to the light, and participated in the synthesis of alkaloids in the plant.