The present invention is directed to a transgenic plant and a method for producing the same. In particular, the present invention is directed to a transgenic plant or a plant cell in which a nucleic acid molecule encoding an m6A demethylase is introduced, wherein said m6A demethylase has the following two domains: i) N-terminal domain (NTD) having the function of AlkB oxidation demethylase; and ii) C-terminal domain (CTD). The present invention is also directed to a method for producing said plant, comprising introducing a nucleic acid molecule encoding an m6A demethylase into a regenarable plant cell, and regenerating a transgenic plant from the regenerable plant cell.