From far away, the top of a leaf looks like one seamless surface; however, up close, that smooth exterior is actually made up of a patchwork of cells in a variety of shapes and sizes.
Interested in how these cells individually take on their own unique forms, Caltech biologist Elliot Meyerowitz, postdoctoral scholar Arun Sampathkumar, and colleagues sought to pinpoint the shape-controlling factors in pavement cells, which are puzzle-piece-shaped epithelial cells found on the leaves of flowering plants.
They found that these unusual shapes were the cell's response to mechanical stress on the microtubule cytoskeleton—protein tubes that act as a scaffolding inside the cells. These microtubules guide oriented deposition of cell-wall components, thus providing structural support.
The researchers studied this supportive microtubule arrangement in the tissue of pavement cells from the first leaves—or cotyledons—of a young Arabidopsis thaliana plant (right).
By fluorescently marking the cells' microtubules (yellow, top surface of cell; purple, bottom surface of cell), the researchers could image the cell's structural arrangement—and watch how this arrangement changed over time.
They could also watch the microtubule modifications that occurred due to changes in the mechanical forces experienced by the cells.
Microtubules strengthen a cell's structure by lining up in the direction of stress or pressure experienced by the cell and guiding the deposition of new cell-wall material, providing a supportive scaffold for the cell's shape.
However, Meyerowitz and colleagues found that this internal stress is also influenced by the cell's shape. The result is a feedback loop: the cell's shape influences the microtubule arrangement; this arrangement, in turn, affects the cell's shape, which modulates the microtubules, and so on.
Therefore, the unusual shape of the pavement cell represents a state of balance—an individual cell's tug-of-war to maintain structural integrity while also dynamically responding to the pushes and pulls of mechanical stress.
The results of the study were published in the journal eLife on April 16. Elliot Meyerowitz is George W. Beadle Professor of Biology and an investigator with the Howard Hughes Medical Institute.
Written by Jessica Stoller-Conrad
Caltech Media Relations
Deborah Williams-Hedges | Eurek Alert!
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research