Influence Of Caluim Signal On The Growth And Polysaccharide Accumulation Of Dendrobium Officinale Protocorm Under Photoinduction

Milti-function landscape plant has not only the ornamental value, but also has the advantages over ecological environment rehabilitation and medical care functions, now the protection and development of this resource have become a new tendency in the field of gardening and the market of the biological health care product. Dendrobium officinale is a special local species of China, which is a typical multi-function landscape plant, its characterized by outstanding flowers and elegant color, which has a high ornamental value, it contains a lot of secondary metabolites, which is useful in anti-tumor. However, Dendrobium officinale has the disadvantages of low production rate, long growth cycle, and it can hardly survival, which caused the high price and the inadequate supply of the wild resources and its biological health products markets. How to make a balance between the protection of species that has been listed to the "endangered species needed careful protection" between satisfying the increasing demand of the market at the same time? It is a innovative way to seek highly effective and economical substitute plants and to develop the multi-landscape plants for the purpose of supplying demands of the market. As a special tissue of Dendrobium officinale, Protocorm has the advantages of high speed proliferation, short production cycle, and has the same medicinal substance and pharmacological action as the wild plants, which can be produced in large scale and take the place of Dendrobium officinale and work as bio-reactor. Thus, Protocorm can be used as bio-reactor to produce the polysaccharide content of Dendrobium, and to replace the wild plants as a medical source, which is a effective way to achieve the sustainable utilization of the wild Dendrobium officinale resources.As a main single of the environment, light quality can be sensed by plants and it is able to adjust a series of primary metabolism and secondary metabolism. To improve the medical value of landscape plants in production has become a hot topic of research at home and aboard. Calcium is the secondary element of delivering environment single, research results show that calcium can not only conduct plants’ reflection to environmental factors such as drought, low temperature, heat shock and hard light, it can also control the combination of some medical elements contained in plants. At present, researches to the conductive function of the calcium signaling in guiding the accumulation of plant’s medical elements are still limited. All though former researchers carried out studies on areas of the light quality’s influences on plant growth and the secondary metabolism of plants, while, to bio-reactor of Dendrobium candidum protocorm, in the synthesis of polysaccharides, the reaction of the calcium signaling towards different light quality is still a question worth to be carefully analyzed. So, this research aims to apply Dendrobium candidum protocorm as the experiment material, and use the method of inhibiting through different light quality and the calcium signaling, to explore weather the light quality has impacts on the bio-reactor of the Protocorm plants? Which kind of light quality and its matching is most effective? And how the calcium react to the impacts of effective light quality? This research can not only fulfill the research results of the calcium singing’s impacts on plant growth, but also provide theoretical guidance to the polysaccharides production of the Dendrobium candidum protocorm. The research results are as follows:Different light qualities have different influences to the Biomass Dendrobium candidum protocorm and the Polysaccharide accumulation.1.The light mixture of red and blue has a better effect to the biomass Dendrobium candidum protocorm and the Polysaccharide accumulation, in which the production of Polysaccharide under the influence of the light quality red/blue 1:3 is high; the production of Biomass and Polysaccharide is similar to each other when it is under the single blue and white light; Biomass under single red is the lowest, and the Polysaccharide contain is slightly higher than that under single white light, and the production is close to that under single white light.2. The differences of the Photosynthetic characteristic are the main causes of different biology yield and the polysaccharide yield under various Protocorm, the mixture of red and blue color has a positive effect to the combination of chlorophyll and promotion of the Photosynthetic characteristic, which will increasing the photosynthate and promote the accumulation of the biomass and polysaccharide. Experiment results show that the 1:3 light quality is most effective; while, the single red light or blue light have bad effects to the growth of the Protocorm’s photosynthetic apparatus.3. The Carbohydrate Metabolism of the Dendrobium candidum protocorm has a obvious impacts on Polysaccharide accumulation, and the effects vary according to different light qualities, under the mixture of the red and blue light, both the SS and SPS activity, the content of sucrose, fructose and glucose are higher, in which the tendency of glucose’s light response is similar to that of polysaccharide, the glucose may be the synthetic precursor of the polysaccharide of protocorms.That is to say, the red/blue 1:3light quality can successfully promote the biomass and accumulation of polysaccharide through improving photosynthetic capacity and carbohydrate metabolism level, and this promotion has a calcium dependency, the related mechanism of which is:1). It works through increasing the content of CaM and the activity of the Ca2+-ATPase, increasing the Ca2+-ATPase’s control over photosynthetic apparatus, and promoting the chlorophyll content and Photosynthetic characteristic of Dendrobium candidum protocorm, to strengthen the photo-productivity and increasing the accumulation of biomass; 2). To increase the Ca2+-CaM signing’s control to the carbohydrate metabolism, and to promote the SS and SPS activity, to increase the contents of sucrose, fructose and glucose, and to provide adequate synthetic precursor for polysaccharide, and thus increase the contents of polysaccharide.All in conclusion, to increase the production of the Dendrobium candidum protocorm is workable. In modern the agricultural scaled production, to apply the red/blue 1:3 light quality’s LED light to replace the white light is a effective method to improve the quality of the Dendrobium candidum protocorm.