Transgenic plants and plant cells comprising a reduced expression of invertase inhibitors

A process for producing a transgenic plant, whose seeds have an increased amount of reserve material in comparison with a wild-type plant due to the reduction or elimination of the expression of an endogenous invertase inhibitor protein during the development of seeds so that the activity of invertase, which is subject to a regulation by the invertase inhibitor protein, is increased during the development of seeds leading to an increased accumulation of reserve material in the seed, said process comprising the steps of:

• (a) obtaining a nucleotide sequence coding for the invertase inhibitor protein expressed during seed development in flowers with young ovules;
• (b) inserting the coding nucleotide sequence in a DNA construct in anti-sense orientation next to a promoter as a regulatory unit;
• (c) transforming a plant cell of a plant, from which the coding nucleotide sequence was obtained, with the DNA construct;
• and
• (d) cultivating the plant cell and regenerating a plant, wherein the expression of the endogenous invertase inhibitor protein is reduced or eliminated during seed development.