Establishment Of Talen For Potato Targeted Genome Mutation And Its Application In Starch Modification

Potato is one of the four major food crops, and it is also one of the important model plants on plant molecular genetics research. The application of potato starch has distinct advantages on the production of papermaking industry, food processing industry, adhesives and feed processing industry, so it is also a kind of important and raw material of industrial starch. Starch can be divided into amylose starch and amylopectin according to its structural differences, the ratio of amylose and amylopectin content affects the structure and characteristics of starch granule, which further affects the quality, functions and applications of starch. It is involved in a variety of enzymes during potato starch synthesis processes, among which GBSS(granule bound starch synthase), SS(starch synthase) and SBE(starch branching enzyme) are the key enzymes. Their activity has great influences on the ratio between potato amylose and amylopectin,starch chain length and structure. So far, for potato?s GBSS, SS and SBE gene, using genetic engineering to improve the potato starch properties has made significant progress, someone have successfully obtained new potato material with low amylose, high amylopectin through translation expression and RNAi technology. Due to the limitations of RNAi technology, there are some problems,such as the target gene mutant materials contain poor stabilityis, the target gene transcription activity is difficult to achieve full ?knockout?, RNAi expression units need to be permanently integration. It is urgently needed a new method to thoroughly realize the disablement for the specific target gene, and can obtain stable potato germplasm material to better meet the needs of the potato varieties breeding.In recent years, the genetically modified engineering research represented by the zinc finger nuclease(ZFN) and(transcription activator- like effector nucleases) TALEN becomes the most potential new technology tool during the gene engineering orientation and the application in the gene engineering field. In this research,we aim to first establish a high efficient TALEN platform for precise genome mutation in potato.TALENs with high efficacy and sequence specificity will be designed, evaluated and tested taking into account of complexity and polyploidy of potato genome.Customized TALENs will be made to target starch biosynthase genes,such as GBSS, SS, SBE. Through TALEN designing, constructing, expressing, transformation and screening, obtained target gene knockout mutants will be analysis for starch characteristics.To achieve the orientation of the target gene in the potato genome knockout, and provide the basis for the study of the potato starch synthesis mechansism. Modified potato lines can be further followed through traditional breeding for phenotype test in progenies.Completion of the proposed research will establish a new paradiam manipulation for basic and applied research.