Creating valuable crop plants utilized by molecular breeding and genome editing techniques

Abstract

  Crops used for current agriculture have been largely modified from the original plants by various breeding techniques. Crossing between plants with good traits allows to generate a plant with desired characteristics. Mutants with desired properties are also established by choosing from the plants treated by radiation or chemicals as mutagen. Recently, crops possessing new traits have been developed using recombinant DNA technologies, and they are widely distributed in the world. Genome editing technique was developed around 2010. A tool for genome editing, such as CRISPR/Cas9 consisting of an artificial nuclease that recognizes specific sequences, induces a desired mutation into a specific gene. We developed a novel genome-editing system using dMac3, a translation enhancer, and optimized for plants. This increases the efficiency of the targeted mutagenesis. We produced a CRISPR/Cas9 gene that targeted the granule-bound starch synthase gene (GBSS) involved in the production of amylose in the starch of the tubers. Using this, we created potato GBSS mutants in which four alleles of potato tetraploid genome contained mutant genes, resulting in a property of low amylose trait in their tuber starch.