Prodn. of potato plants with suppressed tuber sprouting - by genetic modification to reduce sucrose concn.

摘要

Genetically modified potato plants in which tuber sprouting is suppressed are produced by a process in which the concn. of sprout-inducing sucrose is reduced by inhibition of starch-degrading enzymes and/or by degradation of sucrose already formed, by means of a recombinant double-stranded DNA mol. (I) which is localised in a plasmid and integrated into the genome of potato plants. (I) comprises: (a) a promoter that is functional in plant cells; (b) at least one coding sequence in sense and/or antisense orientation which can be coupled to a signal sequence and is fused to the promoter in such a way that the coding or noncoding strand can be read; and (c) a transcription termination and polyadenylation signal sequence that is functional in plants. Also claimed are: (1) the use of plasmid p35S-CW-INV (DSM 5788), which contains an invertase gene, to produce transgenic potato plants in which the mobilisation of starch in the tuber storage tissue is suppressed to improve the storage properties of the tubers and inhibit sprouting; (2) the use of plasmid p35S-CW-INV to produce potato plants in which enrichment of reducing sugars in the tubers at storage temps. above 8 deg.C is inhibited; (3) potato tubers whose storage properties are improved by suppression of sprouting; and (4) the use of tubers (3) to produce potato plants whose tubers have improved storage properties.