PROBLEM TO BE SOLVED: To provide a mutant gene having functions to regulate the oil and fat content in a seed, and to provide a method for regulating the oil and fat content in the seed. SOLUTION: There is a positive correlation between the sum total of GFP (green fluorescent protein) fluorescent intensity and the oil and fat content by expressing an oleosin-GFP fusion protein as a gene selected from among the group consisting of the family Gramineae, the family Brassicaceae, and the family Salicaceae. Specifically, a mutant protein having a consensus sequence in which the twelfth amino acid residue from the N-terminal side is substituted with another amino acid is derived from a mutant gene encoding the mutant protein having functions to regulate the oil and fat content in the seed in the amino acid sequence of the protein. COPYRIGHT: (C)2009,JPO&INPIT
