PROBLEM TO BE SOLVED: To provide a new method for increasing the production of vegetable oil by promoting the fatty acid synthesis in the plant.
SOLUTION: The present invention provides a new method for promoting the synthesis of fatty acid in a plant. The amount of protein of carboxyl transferase β subunit encoded by accD gene is increased by introducing a promoter sequence of a gene highly expressed in chloroplast at the upstream of an E.coli- type acetyl CoA carboxylase accD gene by chloroplast transformation technique. The amount of protein of other subunit constituting acetyl CoA carboxylase is also increased by this process. Since the acetyl CoA carboxylase is the key enzyme of the first stage of fatty acid synthesis, the synthesis of fatty acid can be promoted by the method of the present invention. The transformed vegetable produced by the method exhibits remarkable promotion of fatty acid synthesis, prolonged life of the leaf, increased yield of seeds and improved productivity of the plant body.