NOVELTY - Plant body (I) expressing a chimeric protein, where a transcriptional factor is fused to a functional peptide that converts an arbitrary transcriptional factor into transcriptional repression factor and the transcriptional factor comprises: (a) a protein comprising an amino acid sequence; (b) a protein comprising an amino acid sequence that has e.g. a deletion of amino acids with respect to amino acid sequence; and (c) a protein encoded by a polynucleotide hybridizing under stringent conditions to a polynucleotide that comprises a nucleotide sequence complementary to nucleotide sequence, is new.    USE - (I) is useful for producing high fat and oil contents in seeds, where the fats and oils are useful in household and industrial applications, and as raw materials for biodiesel fuel.    ADVANTAGE - The plant weight is significantly improved. (I) has improved plant weight and exhibit improved biomass level. (I) has low purification cost and transportation cost. (I) reduces the production cost of fats and oils.    DETAILED DESCRIPTION - Plant body (I) expressing a chimeric protein, where a transcriptional factor is fused to a functional peptide that converts an arbitrary transcriptional factor into a transcriptional repression factor and the transcriptional factor comprises: (a) a protein comprising an amino acid sequence of SEQ ID No. 2, 4, or 6; (b) a protein comprising an amino acid sequence that has a deletion, a substitution, an addition, or an insertion of amino acids with respect to the amino acid sequence of SEQ ID No. 2, 4, or 6 and having activity of accelerating transcription; and (c) a protein encoded by a polynucleotide hybridizing under stringent conditions to a polynucleotide that comprises a nucleotide sequence complementary to the nucleotide sequence of SEQ ID No. 1, 3, or 5 and having activity of accelerating transcription, is new, where the sequences not defined here may be found at ftp://ftp.wipo.int/pub/published-pct-sequences/publication. INDEPENDENT CLAIMS are included for:    (1) a chimeric protein, where a transcriptional factor comprising any one proteins of (a)-(c) is fused to a functional peptide that converts an arbitrary transcriptional factor into a transcriptional repression factor;    (2) a gene encoding the chimeric protein;    (3) an expression vector containing the gene; and    (4) a transformant containing the gene.