The National Science Foundation’s 50^th anniversary edition Resource Guide 2000 highlights 50 discoveries or advances that NSF believes have had the most impact or influence on every American’s life. NSF call’s the list it’s "Nifty 50" in honor of the Foundation’s 50^th anniversary.

Five plant research discoveries or advances are among the Nifty 50. The plant research examples are plant genome research on Arabidopsis; plant research leading to edible vaccines; genomics biopharming with plants; research on plants to overcome heavy metals; and plant research to overcome salt toxicity. Some other discoveries cited in the Nifty 50 include the Internet; Magnetic Resonance Imaging; Effects of Acid Rain and other major advances in science. Following are NSF’s summaries of the five highlighted plant research discoveries:

Arabidopsis - A Plant Genome Project

With NSF support, biologists today are mapping all of the genes of a model organism--identifying the sequence and location of each gene. Scientists have already made fundamental discoveries that may lead to the development of improved crops and plant-based products.

NSF began working with leaders in plant biology in the 1980s to foster a spirit of cooperation and to encourage the use of the model plant in research. In 1990, NSF led a multi-agency, multi-national project to identify all the genes in Arapidopsis thaliana (and thus to create a genetic road map to flowering plants) by the end of 2000.

The general belief is the Arabidopsis thaliana is so similar to most other plants that when properties of it are found, those properties likely exist in all other flowering plants. NSF researchers expect that by analyzing the structure and function of genes in Arabidopsis thaliana, they are laying the groundwork for studying the biology of all other plant species.

What NSF and researchers have learned so far includes:

• Disease resistance. Some plants are more resistant than others to viral, bacterial or fungal diseases. Identification of specific disease-resistant genes likely will allow for increased numbers of plants that are resistant to disease.
• Environmental response. Changes in response to light, temperature, water availability, salinity, air quality and other environmental factors. Genes for cold tolerance have been identified.
• Plant hormone response. Scientists have discovered how the plant hormone, ethylene, affects a wide variety of plant processes, including the ripening of fruit, wilting of flowers and changing of leaves' color.
• Commercial applications. Similarities in many plants allow manipulation of grains, fruits and flowers to eventually create improved crops and novel, plant-based products, including biodegradable plastics produced in crops and improved and higher quality vegetable oil with reduced polyunsaturated fat.

Edible Vaccinations

Vaccinating people with edible plants is a new idea that appears to hold great promise. NSF and other government agencies are funding research that could make vaccinating large groups of people easier and smoother. NSF provides funds for the research that has developed much of the knowledge and many of the tools necessary to engineer plants in order to deliver vaccines in an edible form.

Current research is focused at mixing viral or bacterial DNA in a formula, which is then inserted into soil bacteria. When a plant takes on the bacteria, therapeutic DNA becomes stitched into the plant's genetic makeup. As the plant grows, its cells start to produce whatever proteins the new genes are designed to make. When the plant or fruit is eaten, immunization starts, prompting the body to produce the appropriate antibodies.

Researchers in Ithaca, NY, are working to develop bananas to produce antigens so that they can be used as edible vaccines against diarrhea caused by the E. coli bacteria. Recently, these researchers transformed potatoes to produce an E. coli protein that then produced immune responses in human volunteers who ate the raw potatoes. These researchers are now trying to introduce the same antigens in raw bananas, a medium more palatable than raw potatoes.

Edible vaccines hold great potential, especially in Third World countries where transportation costs, poor refrigeration and needle use complicate vaccine administration.

While research is also being conducted with laboratory animals, diabetics may someday benefit from an edible form of insulin. NSF and other government-agency and industry-funded researchers have developed technologies that permit the introduction of a hybrid gene that produces human insulin in potatoes. For diabetics, insulin-bearing potatoes may help train the body's defenses to stop reacting to insulin as if it were a foreign material.

Genomics Bio-Pharming With Plants

Despite controversy over possible safety issues, plant or agricultural biotechnology appears to produce better health and a cleaner, safer environment.

NSF-funded and other government agency research is helping farmers produce food with less pesticide residues, which results in cleaner and safer water.

Lactose intolerance and other food-related ailments could become a thing of the past if allergens in milk and wheat products are eliminated or greatly reduced. Vegetables with higher vitamin E content are expected to help fight heart disease, while an improved strain of rice with enhanced levels of vitamin A and iron will help battle nutritional deficiencies in many people's diets.

An example of recent plant pharmaceuticals is taxol, a secondary plant product derived from the bark or needles of the Pacific Yew tree. Taxol has been found to be effective against certain types of cancer. A synthetic form of taxol is being developed, with the goal of producing larger quantities of taxol and reducing damage or destruction to Pacific Yew trees.

Plastic soda bottles and packaging peanuts found on beaches, riverbeds or mountain trails may no longer be seen as unsightly trash as new forms of plastic may soon allow these items to biodegrade naturally.

Overcoming Heavy Metals

Up to 12 percent of soils under cultivation around the world contain metals that stunt plant growth and development and result in poor harvests. In the past, plant breeders dealt with this problem by crossing metal-sensitive plant varieties with species that thrive in this type of poor soil. NSF-funded researchers are using genetic engineering to improve plant traits, ranging from pest resistance to nutritional value, from developing plants that flourish on metal-rich soils, to helping other plants clean up heavy-metal contamination.

NSF-funded researchers at Cornell University are studying aluminum toxicity and tolerance levels in plants, since aluminum levels in plants are a major factor limiting crop productivity. This research has shown that aluminum starts a process through which certain acids are discharged into the soil. These acids in the soil protect the roots from the harmful effects of the aluminum. A better understanding of the mechanisms involved in this process will have important implications for agricultural food production.

Understanding plant iron uptake is highly important because one-third of the world's soils are iron deficient. Iron deficiency in humans is the most prevalent nutritional problem in the world today, affecting an estimated 2.7 billion people in industrial and developing countries. Plants are the major source of iron for most of the world; ensuring that plants have higher amounts of iron would help in solving an important human nutritional problem.

In the future, crops could be manipulated to become several times richer in iron, or become so efficient at extracting iron from the ground that they could grow in soils that would not normally support them. Research may also lead to the discovery of genes responsible for uptake or absorption of other metals, such as copper, by plants. Manipulating these genes could lead to phytoremediation, a method of removing pollutants from industrial wasteland by growing plants on it. This process may become more efficient if plants become able to absorb greater quantities of metals from the ground.

Overcoming Salt Toxicity

Almost one-third of the irrigated land on earth is not suitable for growing crops because it is contaminated with high levels of salt. More farmable land is lost through high salt levels in soil than is gained through the clearing of forest resources.

Most plants are highly sensitive to salty conditions, which cause stress and significant biochemical change due to absorption and influx of sodium from the salty soil. However, NSF-funded scientists are studying approaches that will lead to plants that can tolerate salty growing conditions.

In recent years, it has become clear that cells of higher plants are capable of adjusting to high levels of salt. In fact, if exposed in a gradual manner, plants can grow and reproduce during exposure to very high concentrations of sodium. What distinguishes salt-tolerant species from susceptible plants is the ability to use or "turn on" this process when necessary. By understanding the signaling system that allows a plant to sense excess sodium in the environment and then make necessary adjustments, plant biologists will be able to influence the growth of crop plants in arid and inhospitable conditions.

Work at the University of Arizona and other university labs is under way to identify what determines or causes salt tolerance in plants. This research has led to the identification of a location in the plant genetic code necessary for salt tolerance.