Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Advance in understanding cellulose synthesis

16.06.2009
Cellulose is a fibrous molecule that makes up plant cell walls, gives plants shape and form and is a target of renewable, plant-based biofuels research.

But how it forms, and thus how it can be modified to design energy-rich crops, is not well understood. Now a study led by researchers at the Carnegie Institution's Department of Plant Biology has discovered that the underlying protein network that provides the scaffolding for cell-wall structure is also the traffic cop for delivering the critical growth-promoting molecules where needed.

The research, conducted in collaboration with colleagues at Wageningen University in the Netherlands and published in the advance online publication (AOP) of Nature Cell Biology on June 14th, is a significant step for understanding how the enzymes that make cellulose and determine plant cell shape arrive at the appropriate location in the cell to do their job.

"Cellulose is the most abundant reservoir of renewable hydrocarbons in the world," remarked Carnegie's David Ehrhardt, a coauthor. "To understand how cellulose might be modified and how plant development might be manipulated to improve crop plants as efficient sources of energy, we need to first understand the cellular processes that create cellulose and build cell walls."

Plant cells have rigid walls that cannot easily change shape. There are many cell types, spiky trichomes to fend off bugs and sausage-shaped guard cells that regulate the plant's breathing pores, as examples. In a previous study using the model plant Arabidopsis, Ehrhardt and team used groundbreaking imaging techniques to watch the molecules that create this array of shapes. It provided the first direct evidence for a functional connection between synthesis of the cell wall and an array of protein fibers—called microtubules—that provide the scaffolding that allow diverse plant cell shapes to be created as the cell wall pushes outward.

In that study, the group engineered plants to produce a fluorescent version of cellulose synthase, the enzyme that creates cellulose fibers. They also included a fluorescent version of tubulin, the protein from which microtubules are built. Using advanced imaging techniques, they tracked the motion of single fluorescent molecules, and found that cellulose synthase moves along "tracks" defined by the microtubules.

In this paper, the researchers looked at how the association between the cellulose synthase complexes and microtubules begins. The scientists were able to watch individual cellulose synthase complexes as they were delivered to the plasma membrane—the permeable film that surrounds the cell, but is inside the cell wall— and found that the microtubules not only guide where the complexes go as they build the cell wall, but microtubules also organize the trafficking and delivery of the cellulose synthase complexes to their place of action.

They also looked at the role in trafficking of a structural element called the actin cytoskeleton that helps move organelles and maintains the cell's shape. They found that it appears to be required for the general distribution of the cellulose synthase complexes, whereas microtubules appear to be required for final positioning.

When there is a disruption of the complexes through a stressor such as a rapid change in water movement (osmotic stress), active cellulose synthase complexes disappear and organelles accumulate just under the plasma membrane. These organelles contain cellulose synthase and are tethered to the microtubules by a novel mechanism. Previously Ehrhardt and team found that plant microtubules move by shortening at one end while lengthening at the other end. They do this one tubulin molecule at a time, in a process the researchers call treadmilling. They now think that the tethering discovered in this research allows the cellulose synthase-containing organelles to stay with the treadmilling microtubules for prolonged periods in times of stress. They found that when the stress abates, these organelles deliver the cellulose synthase to the membrane.

This work was supported by grants from the National Science Foundation (0524334) and the EU Commission (FP6 2004-NEST C1 028974).

The Carnegie Institution for Science (www.CIW.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

David Ehrhardt | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

Speed data for the brain’s navigation system

06.12.2016 | Health and Medicine

What happens in the cell nucleus after fertilization

06.12.2016 | Life Sciences

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>