Compositions and methods for engineering oil content in plants

A method of making a transgenic plant with increased total seed oil content and increased seed yield, said method comprising:

• transforming plant cells with
• (i) a first expression cassette comprising a heterologous plant-expressible seed-specific promoter operably linked to a nucleotide sequence encoding an Arabidopsis diacylglycerol actyltransferase 1 (DGAT1) protein,
• (ii) a second expression cassette comprising a heterologous plant-expressible seed-specific promoter operably linked to a plant or yeast glycerol 3-phosphate dehydrogenase 1 (GPD1) protein, and
• (iii) a third expression cassette comprising a heterologous plant-expressible seed-specific promoter operably linked to the nucleotide sequence as set forth in SEQ ID NO:
• 3 encoding the monoacylglycerol O-acyltransferase 1 (MGAT1) protein to produce transformed cells;
• generating transformed plants from the transformed cells;
• and
• selecting a transgenic plant from the transformed plants, wherein the selected transgenic plant overexpresses said DGAT1, GPD1 and MGAT1 proteins and exhibits increased total seed oil content per transgenic plant and increased seed yield per transgenic plant as compared to a control plant of the same species lacking said first, second, and third expression cassettes and grown under identical growth conditions.