Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists develop plant that produces potential anti-carcinogen

04.02.2004


A Purdue University researcher has successfully engineered plants that may not only lead to the production of anti-carcinogenic nutritional supplements, but also may be used to remove excess selenium from agricultural fields.


This photograph shows the presence of two different selenium compounds in living plant tissue. The image on the left shows a high concentration of MSC, the selenium compound shown to have anti-cancer properties, in one of the plant’s leaves. The image on the right highlights a different selenium compound in the same leaf. The image was obtained using a technique called X-ray absorbance spectroscopy, or XAS, to visualize concentrations of selenium. Red indicates regions of high concentration. Blue and green indicate lower concentration. (Images courtesy of Ingrid Pickering, Proceedings of the National Academy of Science, 97(20); p. 107110).



By introducing a gene that makes plants tolerate selenium, David Salt, professor of plant molecular physiology, has developed plants capable of building up in their tissues unusually high levels of a selenium compound. His interest in selenium stems in part from recent research sponsored by the National Institutes of Health showing that selenium can reduce the risk of developing prostate cancer by 60 percent.

"We now know how to genetically modify plants so they will make this anti-carcinogenic selenium compound," Salt said. "This research gives us the genetic means to manipulate the amount of this material that’s produced in any plant."


Selenium, a mineral that occurs naturally in the soil in some parts of the world, is an essential micronutrient for animals, including humans, but is toxic to animals and most plants at high levels.

However, a few plant species have the ability to build up high levels of selenium in their tissues with no ill effects. These plants, called selenium hyper-accumulators, convert selenium taken up from the soil into a non-toxic form called methylselenocysteine, or MSC.

By inserting the gene responsible for this conversion into Arabidopsis thaliana, a model lab plant that does not tolerate selenium, Salt and his colleagues produced plants that not only thrive in a selenium-enriched environment but also amass high levels of the selenium-containing MSC in their tissues.

"We now know that this gene works," Salt said. "If you put it into another plant, it will make MSC, and we didn’t know that before. So now we’re in a comfortable position to say, ’okay, let’s put this gene into a plant that we can use to make into a nutritional supplement, knowing that we have a very, very high likelihood of it working and producing this compound.’"

The plants that naturally hyper-accumulate selenium would not be good candidates for use as a supplement because they often produce other compounds that may have toxic effects in humans, Salt said.

Salt and his colleagues used two different methods to verify the production of MSC in the engineered Arabidopsis. The first method, called mass spectroscopy, relies on extracting compounds from the plant tissue using a variety of solvents, then running those compounds through a type of machine that identifies their chemical nature.

The other method they used is called x-ray absorbance spectroscopy, or XAS. This technique identifies the various forms of selenium in living plant tissue and can also provide a spatial map of where in the plant these selenium compounds are located.

Both techniques confirmed the presence of MSC in the engineered plants, Salt said.

Other lab studies involving selenium have shown MSC to be the most effective selenium-containing compound in reducing cancer risk in animal models, making it an attractive prospect for eventual use in a nutritional supplement, Salt said.

However, he said the effectiveness of MSC in humans has not yet been tested, because to date there hasn’t been a good commercial source of it that could be used in human trials.

"We would be very interested in knowing the efficacy of MSC in humans, clearly. The problem has been there’s no material to run such an experiment, and that will be an important piece of this story down the road."

Another very different aspect of the research is the possibility of developing plants that remove contaminants from the environment. Selenium contamination, for example, is a major problem in certain parts of the world, including the agricultural region of California’s San Joaquin valley, Salt said. Selenium occurs naturally in the soil in that part of the country, but agricultural practices build that selenium to hazardous levels, he said.

"The central valley of California is a multi-billion dollar agricultural zone, but the intensive irrigation there leaches selenium out of the soil. It’s a major problem for California," he said.

A possible solution, he said, lies in the potential to engineer fast-growing plants capable of removing large quantities of selenium from the soil. Now that he and his colleagues have successfully produced a selenium-hyper-accumulating Arabidopsis, they have the tools to start to develop a plant that would be a good candidate for removing selenium from the soil.

Natural hyper-accumulators process environmental selenium in a series of steps culminating in the production of MSC, and what Salt and his colleagues have re-created in Arabidopsis is the last step in that process.

"Imagine planting something like a cornfield, but with the ability to remove contaminants from the soil," he said. "We’re not yet at that point, but we’re stepping towards that, and that’s a sensible approach. We’ve made the first step by starting with the end product."

Salt’s research is part of collaboration between Purdue and NuCycle Therapy, a small biotechnology company that develops and sells plant-based nutritional supplements. This partnership was funded through a Small Business Technology Transfer grant through the National Institutes of Health National Cancer Institute. The research is published in the current issue of BMC Plant Biology.

Also collaborating in this research were Danielle Ellis, visiting scientist with NuCycle Therapy currently working in the Purdue Center for Plant Environmental Stress Physiology; Thomas Sors, Dennis Brunk, Carrie Albrecht and Brett Lahner with the Purdue Center for Plant Environmental Stress Physiology; Cindy Orser consulting for NuCycle Therapy; Karl Wood with the Purdue chemistry department; H.H. Harris with the Stanford Synchrotron Radiaion Laboratory at the Stanford Linear Accelerator Center (currently at the University of Sydney, Australia); and Ingrid Pickering, also with the Stanford Synchrotron Radiation Laboratory (currently at the University of Saskatchewan).

Writer: Jennifer Cutraro, (765) 496-2050, jcutraro@purdue.edu

Source: David Salt, (765) 496-2114, salt@hort.purdue.edu

Ag Communications: (765) 494-2722; Beth Forbes, bforbes@aes.purdue.edu
Agriculture News Page

Jennifer Curtraro | Purdue News
Further information:
http://news.uns.purdue.edu/html4ever/2004/040203.Salt.selenium.html

More articles from Life Sciences:

nachricht Programming cells with computer-like logic
27.07.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht Identified the component that allows a lethal bacteria to spread resistance to antibiotics
27.07.2017 | Institute for Research in Biomedicine (IRB Barcelona)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>