OsAAP8 mutation leads to significant improvement in the nutritional quality and appearance of rice grains

Members of the permease gene family are responsible for important biological functions in the growth and development of rice. Here, we show that OsAAP8 is a constitutive expression gene, and its translated protein is localized on the cell membrane. Mutation of the OsAAP8 can promote the expression of genes related to protein and amylopectin synthesis, and also promote the enlargement of protein bodies in its endosperm, leading to an increase in the protein, amylopectin, and total amino acid content of grains in OsAAP8 mutants. Seeds produced by the OsAAP8 mutant were larger, and the chalkiness traits of the OsAAP8 mutants were significantly reduced, thereby improving the nutritional quality and appearance of rice grains. The OsAAP8 protein is involved in the transport of various amino acids; OsAAP8 mutation significantly enhanced the root absorption of a range of amino acids and might affect the distribution of various amino acids. Therefore, OsAAP8 is an important quality trait gene with multiple biological functions, which provides important clues for the molecular design of breeding strategies for developing new high-quality varieties of rice.