Abstract: The invention is directed to a process for the generation of male sterility in plants comprising the steps of (a) transforming a plant cell with DNA sequences that selectively inhibit the expression of essential metabolic compounds and (b) regenerating plants from said plant cells. Cells impaired in the biosynthesis of basic metabolic compounds undergo starvation and eventually die. Such pathways include amino acid biosynthesis, nucleic acid biosynthesis and other biosynthetic pathways such as citric acid cycle, pentose phosphate pathway, fatty acid metabolism, vitamin biosynthesis that will render the cell inactive due to nutrient depletion, if one or more enzymes or proteins involved in this pathway would become inactive by using inhibitory DNA constructs.

Abstract: The present invention relates to a new regulon which in storage roots of the sugar beet (Beta vulgaris L.) constitutively expresses the gene which is under its control, such that a transition from anaerobic to aerobic conditions, a transition from normal temperature (appr. 22° C.) to cold temperature (appr. 4° C.) and changing sugar concentrations do not alter the transcription activity of the regulon in the storage root tissue.