Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unlocking Secrets of Plants’ Growing Tips

27.08.2009
Biologist Magdalena Bezanilla and colleagues at the University of Massachusetts Amherst have used a technique they call multi-gene silencing to, for the first time, simultaneously silence nine genes in a multicellular organism. It allowed them to discover molecular secrets of how certain plant tissues know which end is their growing tip, also referred to as polarized growth.

The biologists conducted these experiments in a moss, but the findings illuminate processes in two tissues—root hairs and pollen tubes—found in all seed plants. Root hairs are extremely fine individual cells that grow out of a plant’s root, greatly increasing its surface area to collect water, essential minerals and nutrients. Pollen tubes travel down the flower to fertilize the plant’s egg. Scientists have “a very limited knowledge” at the molecular level of how such cells determine the direction they’re growing, says Bezanilla.

Knowing how to interrupt pollen tube formation in plants such as corn and soybeans, for example, could help prevent genetically engineered crops from interbreeding with wild populations. Aiding root hair growth could boost drought-resistance to other economically important plants.

Bezanilla and colleagues’ research paper in a recent issue of Proceedings of the National Academy of Sciences describes their work in the Physcomitrella patens moss species, which provides a simple, fast-growing model plant. Conveniently, it has a developmental stage when all cells are undergoing tip growth. Another advantage is that its whole genome is known.

The researchers focused on two proteins, actin and formin. Actin, in this case a kind of scaffold-builder needed to form root hairs and pollen tubes, forms filamentous polymers and is important for many cellular processes in species ranging from yeast to man. Formins, like actin, are found in many species and help to control actin polymer formation. Formins are critical for actin-based cellular processes.

Tools in a biologist’s kit can now remove the function of specific proteins—usually one or two at a time—to silence a gene, but in this study the researchers succeeded in silencing a remarkable nine genes at one time. Bezanilla and colleagues systematically silenced the many actin-regulating formins and determined which members of this protein family are needed to generate cells for proper tip growth.

As for silencing nine genes at once, Bezanilla says, “It can be difficult to identify the function of a single gene when it is nested in a highly redundant system or family where another family member will simply step in and take over performing a similar or overlapping function for the one that’s missing.” By using their technique for multi-gene silencing, she adds, “we discerned how to silence the whole family and dissect gene function in that wider context.”

Other tools in the researchers’ kit are methods for re-introducing the silenced genes, either normal or modified versions, the biologist explains. By “swapping parts” from closely related formin proteins and measuring tip growing activity for each combination, her research group eventually concluded that only one intact subclass of formins drives normal growth and controls how the plant recognizes its growing tip. “If you take away any part of the formin, tip growth stops,” says Bezanilla.

Interestingly, the researchers also discovered that this particular subclass of formins is the fastest yet known in any organism. “What’s interesting here is that these mosses don’t grow very fast in nature,” Bezanilla comments. “So we don’t understand why it would need the fastest formin, but it could be that what the plant actually needs at its growing tip is the ability to be flexible and dynamic, that is, adapt quickly to whatever situation is encountered,” she adds.

This required collaboration with biochemist Laurent Blanchoin and colleagues at the University of Joseph Fourier, Grenoble, France. Bezanilla says this teamwork combining in vitro and in vivo studies in a single work “is really the future of where science should be going because as important as it is to know the biochemical function of a particular protein molecule you’re studying, knowing its role in the whole organism is even more important.”

“Finding out that one protein gets its tasks done twice as fast as another in a test tube is interesting, but this difference could be meaningless to a cell,” she explains. “Marrying the in vivo and in vitro approaches is critical to our full understanding of biological processes.”

Magdalena Bezanilla, 413/545-2885; bezanilla@bio.umass.edu

Magdalena Bezanilla | Newswise Science News
Further information:
http://www.umass.edu

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>