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 Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

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 pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>