Delayed flower senescence of Petunia hybrida plants transformed with antisense broccoli ACC synthase and ACC oxidase genes

Petunia (Petunia × hybrida Hort. Vilm.-Andr.) plants were transformed by Agrobacterium with antisense BoACS1 (broccoli ACC synthase) and antisense BoACO1 (broccoli ACC oxidase) coding sequences of enzymes involved in biosynthesis of ethylene in broccoli plants. The integration of these genes with an antisense orientation was verified by PCR analyses of kanamycin-resistant regenerants. The expression of transgenes and endogenous genes was further confirmed by RT-PCR analysis. Production of ethylene in shoot tissues was reduced among most transgenic plants. Flowers of transformants, especially excised flowers, generally remained fresh longer than those of untransformed controls. The delayed flower senescence was more pronounced with the antisense BoACO1 than the antisense BoACS1. Transgenic tissues were, nevertheless, still responsive to ethylene. We conclude that the antisense BoACO1 gene from Brassica oleracea is able to reduce ethylene biosynthesis and delay flower senescence of Petunia hybrida more efficiently than the antisense BoACS1 gene.