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 Solving the efficiency of Gram-negative bacteria
22.03.2019 | Harvard University

nachricht Bacteria bide their time when antibiotics attack
22.03.2019 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>