Basic Tools for Crop Improvement though Biotechnology
Four years ago, we started an effort in functional genomics and DNA sequencing has led to the development of one of the largest collections of genes expressed in ornamental plants (petunia) in the world. After conducting focused microarray experiments, we have isolated several genes that we have identified to have potential utility for use in genetically engineering plants with altered hormone responses, altered floral fragrance, and a variety of other potentially valuable characteristics. We have also isolated several genes that appear to be expressed in specific floral tissues (ie. petals), and many of these contain DNA sequence that shares little or no similarity to other genes of known function in any other plant. We are currently engineering many of these genes to either overexpress and/or knock out their expression in transgenic plants in an effort to uncover their biological function. Results have been promising to date, leading to the isolation of genes involved in the synthesis of several interesting biochemicals: methylbenzoate, a chemical giving flowers a sweet fragrance (Negre et al., 2003; Underwood et al, 2005); isoeugenol - clove oil – a chemical giving flowers a spicy fragrance; benzylbenzoate, used commercially as an insecticide ; 2-phenylethanol (rose oil) and beta-ionone, the two major constituents of rose fragrance. As a result of these efforts, we have produced transgenic plants with altered fragrances that are perceived differently by humans, as measured by sensory panelist analysis of engineered flowers.
Source: • American Floral Endowment Special Research Reports #304