Iowa State scientists demonstrate first use of nanotechnology to enter plant cellsMay 17, 2007AMES, Iowa -- A team of Iowa State University plant scientists and materials chemists have successfully used nanotechnology to penetrate plant cell walls and simultaneously deliver a gene and a chemical that triggers its expression with controlled precision. Their breakthrough brings nanotechnology to plant biology and agricultural biotechnology, creating a powerful new tool for targeted delivery into plant cells. The research, "Mesoporous Silica Nanoparticles Deliver DNA and Chemicals into Plants," is a highlighted article in the May issue of Nature Nanotechnology. The scientists are Kan Wang, professor of agronomy and director of the Center for Plant Transformation, Plant Sciences Institute; Victor Lin, professor of chemistry and senior scientist, U.S. Department of Energy's Ames Laboratory; Brian Trewyn, assistant scientist in chemistry; and Francois Torney, formerly a post-doctoral scientist in the Center for Plant Transformation and now a scientist with Biogemma, Clermond-Ferrand, France. Currently, scientists can successfully introduce a gene into a plant cell. In a separate process, chemicals are used to activate the gene's function. The process is imprecise and the chemicals could be toxic to the plant. "With the mesoporous nanoparticles, we can deliver two biogenic species at the same time," Wang said. "We can bring in a gene and induce it in a controlled manner at the same time and at the same location. That's never been done before." The controlled release will improve the ability to study gene function in plants. And in the future, scientists could use the new technology to deliver imaging agents or chemicals inside cell walls. This would provide plant biologists with a window into intracellular events. The Iowa State team, which has been working on the research in plants for less than three years, started with an Iowa State University proprietary technology developed previously by Lin's research group. It is a porous, silica nanoparticle system. Spherical in shape, the particles have arrays of independent porous channels. The channels form a honeycomb-like structure that can be filled with chemicals or molecules. "One gram of this kind of material can have a total surface area of a football field, making it possible to carry a large payload," Trewyn said. Lin's nanoparticle has a unique "capping" strategy that seals the chemical goods inside. In previous studies, his group successfully demonstrated that the caps can be chemically activated to pop open and release the cargo inside of animal cells. This unique feature provides total control for timing the delivery The team's first attempt to use the porous silica nanoparticle to deliver DNA through the rigid wall of the plant cell was unsuccessful. The technology had worked more readily in animals cells because they don't have walls. The nanoparticles can enter animal cells through a process called endocytosis - the cell swallows or engulfs a molecule that is outside of it. The biologists attempted to mimic that process by removing the wall of the plant cell (called making protoplasts), forcing it to behave like an animal cell and swallow the nanoparticle. It didn't work. They decided instead to modify the surface of the particle with a chemical coating. "The team found a chemical we could use that made the nanoparticle look yummy to the plant cells so they would swallow the particles," Torney said. It worked. The nanoparticles were swallowed by the plant protoplasts, which are a type of spherical plant cells without cell walls. Most plant transformation, however, occurs with the use of a gene gun, not through endocytosis. In order to use the gene gun to introduce the nanoparticles to walled plant cells, the chemists made another clever modification on the particle surface. They synthesized even smaller gold particles to cap the nanoparticles. These "golden gates" not only prevented chemical leakage, but also added weight to the nanoparticles, enabling their delivery into the plant cell with the standard gene gun. The biologists successfully used the technology to introduce DNA and chemicals to Arabidopsis, tobacco and corn plants. "The most tremendous advantage is that you can deliver several things into a plant cell at the same time and release them whenever you want," Torney said. "Until now, you were at nature's mercy when you delivered a gene into a cell," Lin said. "There's been no precise control as to whether the cells will actually incorporate the gene and express the consequent protein. With this technology, we may be able to control the whole sequence in the future." And once you get inside the plant cell wall, it opens up "whole new possibilities," Wang said. "We really don't know what's going on inside the cell. We're on the outside looking in. This gets us inside where we can study the biology per se," Wang said. The interdisciplinary research collaboration was funded and facilitated by Iowa State's Plant Sciences Institute. The institute sponsors Wang's work to develop a male-sterile, biopharmaceutical corn - the corn contains a therapeutic protein but does not produce pollen. The materials development and synthesis of the nanoparticles in Lin's laboratory was funded by the energy department and the National Science Foundation. Wang and Lin intend to continue their collaboration to further develop the technology and its applications in plants. Iowa State University |
|||||||||||||||||||||
| Related Plant Cell Current Events and Plant Cell News Articles Maize cell wall genes identified, giving boost to biofuel research Purdue University scientists have helped identify and group the genes thought to be responsible for cell wall development in maize, an effort that expands their ability to discover ways to produce the biomass best suited for biofuels production. UCR plant scientist's research spawns new discoveries showing how crops survive drought Breakthrough research done earlier this year by a plant cell biologist at the University of California, Riverside has greatly accelerated scientists' knowledge on how plants and crops can survive difficult environmental conditions such as drought. Iowa State University researcher discovers key to vital DNA, protein interaction A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist calls a "cascade of advances." Popping the cork on biofuel agriculture Scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have identified a novel enzyme responsible for the formation of suberin - the woody, waxy, cell-wall substance found in cork. Potato blight plight looks promising for food security Over 160 years since potato blight wreaked havoc in Ireland and other northern European countries, scientists funded by the Biotechnology and Biological Sciences Research Council (BBSRC) finally have the blight-causing pathogen in their sights and are working to accelerate breeding of more durable, disease resistant potato varieties. Fuels from Biomass: New Technique Can Fast-Track Better Ionic Liquids for Biomass Pre-Treatments Understanding how ionic liquids dissolve lignocellulose will help scientists find new and better ways of producing advanced fuels from biomass They've been dubbed "grassoline" - second generation biofuels made from inedible plant material, including fast-growing weeds, agricultural waste, sawdust, etc. - and numerous scientific studies have shown them to be prime candidates for replacing gasoline to meet our transportation needs. Advance in understanding cellulose synthesis Cellulose is a fibrous molecule that makes up plant cell walls, gives plants shape and form and is a target of renewable, plant-based biofuels research. Breaking the Ties that Bind: New Hope for Biomass Fuels Los Alamos National Laboratory researchers have discovered a potential chink in the armor of fibers that make the cell walls of certain inedible plant materials so tough. Plant Gene Mapping May Lead to Better Biofuel Production By creating a "family tree" of genes expressed in one form of woody plant and a less woody, herbaceous species, scientists at the U.S. Department of Energy's Brookhaven National Laboratory have uncovered clues that may help them engineer plants more amenable to biofuel production. UCR scientists identify stem-cell genes that help form plant organs Plant stem-cells are master cells located at the tip of the stem and are part of a structure called the shoot apical meristem (SAM). Here, the stem cells-all clumped together-divide throughout the life of the plant to give rise to other cells, resulting in the formation of above-ground organs such as leaves, flowers, branches and stem. More Plant Cell Current Events and Plant Cell News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||