New Worlds: Researchers learn how to 'scent' flowers

Have you noticed - as a flower species becomes more beautiful, it is also less likely to have a scent.

By JUDY SIEGEL-ITZKOVICH
flowers 88 (photo credit: )
flowers 88
(photo credit: )
Have you noticed that as a flower species becomes more beautiful, it is also less likely to have a scent? Now a team of Hebrew University of Jerusalem scientists has found a way to genetically enhance the smell of flowers and implant a scent in those that lack one. Odors affect how we choose fruit and vegetables in the markets, perfume and even partners. And yet smell is not just what we sense with our noses - it's also what we taste, notes Prof. Alexander Vainstein, who is heading the team at the Robert Smith Faculty of Agriculture, Food and Environment. "Aroma is of major importance for defining the taste of food," he notes. Scent in flowers and plants is used to attract pollinating insects that help in the creation of fruit. The intensity of scent that a flower emits is influenced by the time of day, weather, age of the flower and its species. In research published recently in the Plant Biotechnology Journal, Vainstein, his research assistant Michal Moyal Ben-Tzvi and other colleagues succeeded in enhancing the scent of a flower 1,000% and in causing it to emit scent night and day. The development, which has been patented by Yissum (HU's technology transfer company), is also to be applied to other agricultural produce. The flower industry will be interested in this development, explains Vainstein. "Many flowers lost their scent over many years of breeding. Recent developments will help create flowers with increased scent as well as producing new scent components." Over a third of participants in Flowers and Plants Association surveys stated that scent influenced their choice of flower purchase. Floral scents are also one of the most popular smells, and the perfume industry expends a great deal of effort trying to reproduce the fragrance of fresh flowers. Vainstein's lab is reportedly the only one in the world that researches both the scent and color of flowers. His greenhouse on the university's Rehovot campus is replete with genetically engineered flowers whose architecture, color and scent the researchers are trying to alter. Israel is the Middle East's flower-producing superpower. Its flower, plant and propagation material exports bring more than $200 million into the economy, each year, and Israel is third only to the Netherlands and Kenya in supplying the EU with flowers. Each year, 1.5 billion stems are exported - twice as many as a decade ago. Just think that when the young state welcomed its first head of state, it had to import a fancy bouquet from Europe. ZOOMING IN ON FISH EMBRYO The Google Earth Web site allows anyone to zoom in on homes, streets and famous buildings in many parts of the world. Now researchers at the European Molecular Biology Laboratory (EMBL) have produced a digital zebrafish embryo that can be magnified in the same way to show the development of zebrafish. It is the first complete developmental blueprint of a vertebrate, the EMBL researchers say. With a newly developed microscope, scientists could for the first time track all cells for the first 24 hours in the life of a zebrafish. The data were reconstructed into a three-dimensional digital representation of the embryo. The study, published in a recent issue of Science, grants many new insights into embryonic development. Movies of the digital embryo and the underlying database of millions of cell positions, divisions and tracks will be made publicly available to provide a novel resource for research and scientific training. To get from one cell to a complex organism, cells have to divide, travel around the body and arrange themselves into intricate shapes and specialized tissues. The best way to understand these dynamic processes is to look at what happens in the first few hours of life in every part of an embryo. While this is possible with invertebrates with a few hundred cells, it has so far been impossible for vertebrates. "Imagine following all inhabitants of a town over the course of one day using a telescope in space. This comes close to tracking the 10,000 cells that make up a vertebrate embryo - only the cells move in three dimensions," says Philipp Keller. Together with Annette Schmidt, he carried out the research in the labs of Jochen Wittbrodt and Ernst Stelzer at EMBL. Two newly developed technologies were key to the scientists' interdisciplinary approach to tracking a living zebrafish embryo from the single cell stage to 20,000 cells: a digital scanned laser light sheet microscope, which scans a living organism with a sheet of light along many different planes so that the computer can assemble a complete 3-D image, and a large-scale computing pipeline operated at the Karlsruhe Institute of Technology. Zebrafish is a widely used organism that shares many features with higher vertebrates. Taking more than 400,000 images per embryo, the interdisciplinary team generated terabytes of data on cell positions, movements and divisions that were reassembled into a digital 3-D representation of the complete developing organism. The new microscopy technology is also applicable to mice, chickens and frogs. A comparison of digital embryos of these species is likely to provide crucial insights into basic developmental principles during evolution. "The digital embryo is like Google Earth for embryonic development. It gives an overview of everything that happens in the first 24 hours and allows you to zoom in on all cellular and even subcellular details," says EMBL's Jochen Wittbrodt. New insights provided by the digital embryo include: fundamental cell movements that later on form the heart and other organs are different than previously thought, and the position of the head-tail body axes of the zebrafish is induced early on by signals deposited in the egg by the mother.