Abstract: The present invention relates to optimized ketolase coding sequences, corresponding coding sequences and genetic constructs alone or in combination with beta-cyclase coding sequences, their use for the expression in plants, in particular in plants of the genus Tagetes, to such genetically modified plants, to a process for the preparation of carotenoid products by culturing the genetically modified plants. The present invention further relates to the expression of optimized ketolase coding sequences alone or in combination with beta-cyclase coding sequences under control of an Antirrhinum majus ANTHIRRHINUM FIDDLEHEAD (AFI) promoter, In addition the invention relates to the use of an AFI promoter for heterologous gene expression, preferably for flower-specific expression of genes in plants of the genus Tagetes, to the genetically modified plants of the genus Tagetes, and to a process for producing biosynthetic products by cultivating the genetically modified plants.

Abstract: Use of a plastid-lipid associated protein promoter (PAP promoter) for heterologous expression of genes in plants of the genus Tagetes.

Abstract: New ketolases for the production of ketocarotenoids in Tagetes Abstract A ketolase having a polypeptide sequence SEQ ID NO:6, a sequence derived from SEQ ID NO:6 by substitution, insertion or deletion of aminoacids, which has an identity of at least 60% with the respective sequence SEQ. ID. NO: 6 or a functionally equivalent fragment of the sequences mentioned above and processes for production of ketocarotenoids in Tagetes.

Abstract: The invention relates to methods for the targeted transgenic expression of nucleic acid sequences in tissues of plants, and to transgenic expression cassettes and expression vectors comprising promoters with expression specificity for floral tissues. The invention further relates to organisms (preferably plants) transformed with these transgenic expression cassettes or expression vectors, to cultures, parts or propagation material derived from these organisms, and to their use for the production of foodstuffs, feedstuffs, seed, pharmaceuticals or fine chemicals.