Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Research reveals how cells protect against stress


Stress happens, and over the eons all species of living things have evolved all sorts of ways to cope. Now, new research has revealed that organisms as diverse as humans and plants share a common set of stress-protection maneuvers that are choreographed by the metabolic machinery in their cells.

The research led by Sarah M. Assmann, the Waller Professor of Plant Biology at Penn State, will be published in the 15 August 2002 issue of the journal Nature.

"We have shown, in more detail than was known before, the chain of cellular events that begins with an environmental stress and ends with an organism’s protective response to that stress," Assmann says. "We also have discovered some previously unknown steps in that process."

Among the team’s discoveries is that one cellular-processing step that originally was discovered in human cells also occurs in plant cells. "A human autoimmune disease and a disorder associated with breast cancer are known to result from a defect in this process, " Assmann says.

Specifically, the Assmann team studied a process triggered in plants by abscisic acid (ABA), a hormone that plants produce when they are stressed by drought. Assmann’s lab discovered two years ago that the ABA hormone activates a type of protein called a kinase, which attaches phosphate groups to other proteins. The resulting cascade of events ultimately causes closure of microscopic pores on the plants’ leaves in an effort to limit the loss of moisture.

In the present research, Assmann’s group found that one of the targets of this ABA-activated kinase is a specific protein that binds RNA. Assmann’s group further discovered that the ABA-induced phosphorylation of the RNA-binding protein caused its association with the RNA encoding dehydrin, a protein known to confer stress-resistance to plant cells.

Scientist have long known that, in both plant and animal cells, proteins designed to do particular jobs are produced from the genetic blueprint contained in the DNA inside the nucleus. In a process known as transcription, nuclear machines first copy the genetic code from the DNA molecules into a "transcribed" RNA molecule and then moves the RNA from the nucleus into the cell’s cytoplasm, where it is "translated" into a protein. But Assmann and other researchers are discovering that RNA-binding proteins mediate a lot of cut-and-paste processing of the newly transcribed "raw" RNA before it is remodeled into "messenger" RNA and allowed to leave the nucleus carrying the blueprint for making a protein.

"A new paradigm that our research suggests is that the ABA hormone regulates the protein complement of a cell not only by controlling the initial transcription process but also by controlling the proteins involved in post-transcriptional remodeling of RNA molecules, including RNAs that encode stress-protective proteins," Assmann explains.

Another of Assmann’s discoveries is that ABA regulates the formation of mysterious islands within the cell’s nucleus called "nuclear speckles." Scientists do not yet know a lot about nuclear speckles in plants, but they do know that nuclear speckles in human cells contain proteins associated with the remodeling of RNA.

By expressing in plant cells the RNA-binding protein with a green fluorescent tag attached, Assmann’s group was able to observe the localization of this protein within the living cell. As she watched through the microscope Assmann observed, for the first time, that ABA induced the relocation of the RNA-binding protein within the nucleus. Upon treatment of the plant tissue with ABA, the fluorescently-tagged RNA-binding proteins quickly gathered together into nuclear speckles that looked like green-glowing islands inside the cell’s nucleus. "To our knowledge, such hormonally induced aggregation of RNA-remodeling proteins into nuclear speckles has not previously been observed either in plant or in animal cells," Assmann says.

In addition to giving researchers these and other important details about the processes that produce protective proteins, Assmann’s research also eventually could give farmers more control over the moisture content of their crops." Our research points to a gene-regulation process that, if turned off after a crop matures, would assure that the pores on a plant’s leaves would stay open, allowing it to dry more quickly in the field," Assmann explains. "In a crop like feed corn, for example, such control would be economically beneficial to farmers, who get a better price for their crop if it has reached its optimal moisture content."

In addition to Assmann, other members of the research team include Jiaxu Li, lead postdoctoral associate, postdoctoral associates Sona Pandey and Carl K.-Y. Ng, Ken-ichiro-Shimazaki and Toshinori Kinoshita at Kyushu University (Japan), and Steven P. Gygi of Harvard Medical School.

This research was supported by the National Science Foundation. Photos: high resolution images for publication are available to reporters from a link at

Additional Contact Information:
Sarah M. Assmann: phone 814-863-9579, email

Barbara K. Kennedy | EurekAlert!

More articles from Life Sciences:

nachricht Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München

nachricht Second research flight into zero gravity
21.10.2016 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>