Sweet Potato Sucrose Transporters Genes Specifically Expressed Effects On Tobacco Starch Synthesis

Sucrose is one of the final products of the green plants photosynthesis, and one of the main form of photosynthesis product transportation and distribution in the majority of higher plants, and sucrose transporters plays an important role in sugar transport and distribution. Previous research has shown that sugar is closely related to starch synthesis in plant bodies. First of all, sucrose broken down into glucose and fructose in under the action of sucrose synthetase (SuSy), providing direct substrates for the synthesis of starch. Some studies have shown that the activity of SuSy was significantly positively related to starch accumulation rates. Secondly, sucrose is main or even the only form product from the source to the library during the higher plant photosynthesis long-distance transportation. Sucrose transport depends on the microstructure of plants, phloem sieve molecule is regarded as a main part of the sucrose transport, and sucrose transporters (SUT) is responsible for sucrose transport across the membrane. Thus, genetic improvement of sweet potato starch synthesis approach can not only utilize direct regulation related enzyme gene expression, but also take advantage of adjusting sucrose metabolism and some related genes expression during the transport pathway such as sucrose transporters SUT. Choosing tissue specific promoters to control target gene expression, is the important strategy to realize gene expression control of time and space, it is now widely used in plant quality improvement of resistance of genetic engineering, gene engineering and plant bioreactors, etc. Using microtubule organization specific promoter, especially the phloem specific promoter, may increase the sucrose transporters in microstructure especially the distribution of phloem via expressing genes of sucrose transporters, and that has no effect on other organizations, realizing accurate control sucrose transport in microstructure library and source distribution at the same time.Whether effectively filter out appropriate promoter which has high expression, high specificity and expression intensity in sweet potato is the key to make full use of existing genes, and realize the the directional improvement of sweet potato starch synthesis.Our study screen for microtubule organization specific promoter, can be widely used in sweet potato gene function analysis and the field of genetically modified (GM). On the basis of this study, we can also be further breeding high starch varieties of sweet potato, and to provide better raw materials for sweet potato starch production of fuel ethanol and our country to develop renewable energy. In this study, we connect the relationship between sucrose transporter and starch synthesis with breeding work of high starch closely, that not only has a certain theoretical value, but also has a certain application prospect.