Abstract: The invention provides enhancers for one or more gene promoters, which enhancers are nucleotide sequences rich in A and T bases, the total amount of A and T bases comprising more than 50% of the nucleotide sequence. Particular sequences are identified from the pea plastocyanin promoter which are active as enhancers, as is a solely A/T nucleotide sequence, and methods of carrying out the invention are described.

Abstract: A polypeptide amino acid sequence capable of targeting the plastid inner envelope membrane of a plant, and a nucleotide sequence therefor, are described, as well as a chimaeric gene comprising a gene promoter, a nucleotide sequence encoding a polypeptide capable of targeting the plastid inner envelope membrane of a plant, or a variant, derivative or homologue thereof, a coding sequence and a terminator sequence. A method of transforming plants, such as potato and tobacco, using the targeting sequence so as to increase starch production is also described. The targeting sequence can be used in many other applications.