The new work paints the clearest portrait yet of what it means to be a flowering plant, a unique class of life that arose from a flowerless world a mere 200 million years ago and quickly came to dominate virtually every ecosystem on Earth. It sheds light on how plants diversified and adapted, and in particular how they overcame the unique problems that come with being rooted to a single spot, unable to flee or hide. Also unexpected, flowering plants have nearly identical versions of many human disease genes. That discovery is already giving researchers clues about why certain human diseases produce the symptoms they do. It suggests that plants may eventually be useful not only as a source of novel medicines but also as a screening tool to test the efficacy of experimental drugs for human ailments.
Plants are, after all, much easier and cheaper to grow than mice.
It will lead us to discoveries that are unimaginably interesting. All this from a scraggly eight-inch tall plant called Arabidopsis thaliana. In 1996 an international consortium of scientists banded together with support from government agencies on three continents to form the Arabidopsis Genome Initiative, with the goal of identifying every bit of DNA code carried on the plant's five chromosomes. About 1,000 of those are involved in photosynthesis, all of them stolen from an ancient species of photosynthetic bacteria that learned how to make energy from sunlight about 3.5 billion years ago and at some point took up permanent residence inside green plant cells. Scientists said they were surprised to find that most of Arabidopsis' genes are essentially duplicate copies of other genes in the plant, indicating that at one or more points in the plant's evolutionary history its entire genome accidentally doubled in size.