Enhancement of phosphate absorption by garden plants by genetic engineering: a new tool for phytoremediation.

Although phosphorus is an essential factor for proper plant growth in natural environments, an excess of phosphate in water sources causes serious pollution. In this paper we describe transgenic plants which hyperaccumulate inorganic phosphate (Pi) and which may be used to reduce environmental water pollution by phytoremediation. AtPHR1, a transcription factor for a key regulator of the Pi starvation response in Arabidopsis thaliana, was overexpressed in the ornamental garden plants Torenia, Petunia, and Verbena.

Altering flower color in transgenic plants by RNAi-mediated engineering of flavonoid biosynthetic pathway.

Flower color is mainly determined by the structure of flavonoids, a group of secondary metabolites of plants. The biosynthetic pathway and the genes involved in the pathway are well characterized such that it is possible to change flower color by engineering the pathway by overexpression of heterologous genes and/or suppression of endogenous genes in transgenic plants. Trimming an unnecessary pathway by suppression of endogenous genes is often essential to achieve successful engineering of the pathway and the resultant accumulation of desirable compounds.

Engineering of the rose flavonoid biosynthetic pathway successfully generated blue-hued flowers accumulating delphinidin.

Flower color is mainly determined by anthocyanins. Rosa hybrida lacks violet to blue flower varieties due to the absence of delphinidin-based anthocyanins, usually the major constituents of violet and blue flowers, because roses do not possess flavonoid 3',5'-hydoxylase (F3'5'H), a key enzyme for delphinidin biosynthesis. Other factors such as the presence of co-pigments and the vacuolar pH also affect flower color.