A method to transforming a plant includes coating a microparticle having a diameter of 0.3 to 0.9 μm with at least one type of nucleic acid, bombarding a shoot apex of the plant with the coated microparticle using a gene gun, growing the shoot apex bombarded with the coated microparticle to obtain a plant body, and selecting a transformed plant body from the plant body. The shoot apex is selected from the group consisting of a shoot apex of an embryo of a fully mature seed, a shoot apex of a young bud of a tuber, and a shoot apex of a terminal bud or a lateral bud.