Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plant size morphs dramatically as scientists tinker with outer layer

09.03.2007
Jack's magical beans may have produced beanstalks that grew and grew into the sky, but something about normal, run-of-the-mill plants limits their reach upward.

For more than a century, scientists have tried to find out which part of the plant both drives and curbs growth: is it a shoot's outer waxy layer? Its inner layer studded with chloroplasts? Or the vascular system that moves nutrients and water? The answer could have great implications for modern agriculture, which desires a modern magical bean or two.

Now, in the March 8 issue of the journal Nature, researchers in the Plant Biology Laboratory at the Salk Institute for Biological Studies provide the answer. They succeeded in making tiny plants big and big plants tiny by controlling growth signals emanating from the plant's outer layer, its epidermis.

These findings could eventually be used by agronomists to manipulate plant growth pathways to maximize crop yield, or even reduce leaf size or leaf angle in plants that need to be spaced closely together, says the study's lead author, Joanne Chory, Ph.D., professor and director of the Plant Biology Laboratory and investigator with the Howard Hughes Medical Institute.

... more about:
»Arabidopsis »BRI1 »Epidermis »Steroid »dwarf

Chory and her laboratory team have spent years helping to define how a plant "knows" when to grow and when to stop – which is a "big question in developmental biology," she says. For their experiments, they rely on the model system Arabidopsis thaliana, a small plant related to cabbage and mustard whose genome has been decoded. Over the years, the researchers have built up a whole tool kit, learning how to add and subtract genes in order to determine form and function. Among their discoveries is a class of dwarf plants whose size is about one-tenth the size of a single leaf of the full-sized plant.

Over the past decade, Chory's laboratory and others have shown that these dwarf plants are defective in making or responding to a steroid hormone called brassinolide. Among the genes identified was the plant steroid receptor, BRI1 ("bry-one") that is activated by the steroid. The dwarfed Arabidopsis doesn't express BRI1 at all, unlike normal Arabidopsis, which expresses BRI1 on both the outer waxy, protective epidermis (covering the whole leaf and shoot), and the inner sub-epidermal layer, which contains the chloroplasts that conduct photosynthesis.

In the current study, first author Sigal Savaldi-Goldstein, Ph.D., a postdoctoral researcher in the Plant Biology Laboratory, and Charles Peto, an electron microscopy specialist in the Laboratory of Neuronal Structure and Function, conducted a series of experiments that addressed an old debated question: what tissues of the leaf drive or restrict growth? The answer was simple: the epidermis is in control.

They found that when they drive the expression of the BRI1 receptor in the epidermis of a dwarf Arabidopsis, while leaving the sub-epidermal layer as it was (without BRI1 receptors), the tiny plant morphed into a full-sized plant. In the second set of experiments, they used an enzyme to break down the steroid hormones in the epidermis, and found that a normal sized plant shrunk into a dwarf. "These are simple experiments, but it took 10 years of work in order for us to be able to ask this question," Chory says.

"A second remarkable finding from the study is that "cells in the outer layer talk to the cells in the inner layers, telling them when to grow or to stop growing. This communication is very important to the life of a plant, which can't move and so must have a coordinated system to respond to a changing environment," explains Savaldi-Goldstein.

Gina Kirchweger | EurekAlert!
Further information:
http://www.salk.edu

Further reports about: Arabidopsis BRI1 Epidermis Steroid dwarf

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>