(Press-News.org) Scientists require high-resolution imaging of plant cells to study everything from fungal infections to reproduction in maize. These images are captured with scanning electron microscopy (SEM), where an electron microscope focuses beams of electrons to increase magnification of objects. SEM is a common technique for all fields of science.
However, preparing objects for SEM and other common imaging methods can compromise delicate biological samples. Freeze-drying of material, electron beams, and vacuum pressure in the microscope can all result in cell damage, which is problematic for visualizing cell shape, size, and development. In addition, preparing material to be viewed under the microscope using SEM requires specialized equipment, causing a low throughput and placing a large financial burden on scientific labs.
Researchers at the University of Florida have developed new methods for a less damaging, more cost-effective, and higher-throughput approach for imaging cellular structure. "For visualizing cells of a variety of plant material," explains researcher Jacob Landis, "there are alternatives to the commonly used SEM. Some of these alternatives may be more easily accessible to researchers and do not require specialized equipment for processing prior to imaging."
Landis and colleagues created protocols for an optical sectioning-3D reconstruction method that uses a compound fluorescence light microscope. A compound microscope has multiple lenses to reflect light and project a high-magnification image. The microscope and a mounted camera "sections" the plant cells, capturing pictures of several layers and planes of the sample material. The images are reconstructed into a final 3D image with equal to higher resolution as images produced using SEM.
Landis developed the new protocol (detailed in a recent issue of Applications in Plant Sciences [http://www.bioone.org/doi/pdf/10.3732/apps.1400112]) to see epidermal cells on the surfaces of flower petals. This group of cells reveals extensive information to geneticists, agronomists, and ecologists. Flower epidermal cells cause all types of cellular-level changes that can scale up to influence flower color and development, as well as ecological interactions such as a plant's success in attracting pollinators and avoiding insect enemies.
Unlike in SEM, material to be imaged using the new method gets preserved, allowing for clear imaging months after the collection of any samples. This is valuable when studies require bulk processing of samples. The material is then dehydrated in ethanol alcohol, dipped in a liquid to remove the waxy film that protects the outer layer of petal cells, and mounted in a fluorescent dye to help visualize details under the microscope.
The method was catalyzed by a larger study on the cellular and genetic basis of flower size in the woodland plant group Saltugilia (see Image). Saltugilia plants have a large range of flower sizes and host all types of pollinators--including hummingbirds, bees, and bee flies--while some host no pollinators at all. SEM could not be used to understand these diverse flowers because it is limited to samples 3-5 mm in size. The new optical sectioning-3D reconstruction approach allows for samples as large as 5 cm to be imaged before cutting petals and compromising petal cellular structure.
Optical-sectioning and 3D reconstruction have been informally tested on other plant material, including leaf cells and reproductive organs (stamens, anthers, and sepals). "We believe that any kind of tissue that can be mounted on a microscope slide will be possible to image," says Landis. "I have spent a lot of time using SEM and prepping samples, and optical sectioning with 3D reconstruction is by far the simplest and most cost-effective method I have ever used."
INFORMATION:
Jacob B. Landis, Kayla L. Ventura, Douglas E. Soltis, Pamela S. Soltis, and David G. Oppenheimer. 2015. Optical sectioning and 3D reconstructions as an alternative to scanning electron microscopy for analysis of cell shape. Applications in Plant Sciences 3(4): 1400112. doi:10.3732/apps.1400112
Applications in Plant Sciences (APPS) is a monthly, peer-reviewed, open access journal focusing on new tools, technologies, and protocols in all areas of the plant sciences. It is published by the Botanical Society of America, a nonprofit membership society with a mission to promote botany, the field of basic science dealing with the study and inquiry into the form, function, development, diversity, reproduction, evolution, and uses of plants and their interactions within the biosphere. APPS is available as part of BioOne's Open Access collection.
For further information, please contact the APPS staff at apps@botany.org.
New research has shown that children who display increasing levels of inattention at the age of seven are at risk of worse academic outcomes in their GCSE examinations.
Researchers at the Universities of Nottingham and Bristol studied more than 11,000 children as part of the research which was funded by the Economic and Social Research Council (ESRC) and is published in the Journal of the American Academy of Child and Adolescent Psychiatry.
The findings of the research have a range of implications for parents, teachers and clinicians.
The research was led by Kapil ...
If you're in the market for a new car, and especially if you have a trade-in, the latest research from the USC Marshall School of Business marketing department suggests you aren't getting the deal you think you are getting.
New research from USC Marshall School of Business associate professors of marketing Anthony Dukes and Sivaramakrishnan Siddarth shows that a consumer with a trade-in actually forks over more money to the dealer than consumers without a trade-in.
"The Informational Role of Product Trade-Ins for Pricing Durable Goods" is forthcoming in the Journal ...
Results to be published in the Journal of Family and Economic Issues suggest that having short-term household debt -- credit cards and overdue bills -- increases depressive symptoms. The association is particularly strong among unmarried people, people reaching retirement age and those who are less well educated, according to a new study by lead author Lawrence Berger of the University of Wisconsin-Madison.
These are the first results to show the impact of different types of debt on depression and their effects on different sectors of the US population. Little evidence ...
Scientists are using a variety of buoys and autonomous underwater vehicles to record and archive sounds from marine mammals and fish species in the western North Atlantic through a new listening network known as the U.S. Northeast Passive Acoustic Sensing Network (NEPAN).
Stretching from the northern Gulf of Maine to the New York Bight in the northwest Atlantic Ocean, NEPAN provides year-round, long-term information on the presence and physical distribution of vocal whales, dolphins and porpoises and some fish species. The archived and near-real-time data comes from recorders ...
Researchers at Aalto University (Finland) and Amherst College (USA) have observed a point-like monopole in a quantum field itself for the first time. This discovery connects to important characteristics of the elusive monopole magnet. The results were just published in Science magazine.
The researchers performed an experiment in which they manipulated a gas of rubidium atoms prepared in a nonmagnetic state near absolute zero temperature. Under these extreme conditions they were able to create a monopole in the quantum-mechanical field that describes the gas.
'In this ...
LA JOLLA -- A study tying the aging process to the deterioration of tightly packaged bundles of cellular DNA could lead to methods of preventing and treating age-related diseases such as cancer, diabetes and Alzheimer's disease, as detailed April 30, 2015, in Science.
In the study, scientists at the Salk Institute and the Chinese Academy of Science found that the genetic mutations underlying Werner syndrome, a disorder that leads to premature aging and death, resulted in the deterioration of bundles of DNA known as heterochromatin.
The discovery, made possible through ...
HOUSTON - (April 30, 2015) - With the Millennium Development Goals established by the United Nations in 2000 coming to an end in 2015, and the new Sustainable Development Goals now in the works to establish a set of targets for the future of international development, experts at Baylor College of Medicine have developed a new tool to show why neglected tropical diseases, the most common infections of the world's poor, should be an essential component of these goals.
Using World Health Organization data for the number people at risk of parasitic worm infections in each ...
A detailed study of marine animals that died out over the past 23 million years can help identify which animals and ocean ecosystems may be most at risk of extinction today, according to an international team of paleontologists and ecologists.
In a paper to be published in the May 1 issue of the journal Science, researchers from the University of California, Berkeley, and other institutions report that worldwide patterns of extinction remained remarkably similar over this period, with the same groups of animals showing similar rates of extinction throughout and with a ...
Demand for seafood from wild fisheries and aquaculture around the world has nearly doubled over the past four decades. In the past several years, major retailers in developed countries have committed to source their seafood from only sustainably certified fisheries and aquaculture, even though it is not clear where that supply will come from.
A team of researchers led by the University of California, Davis, has focused its attention on fishery improvement projects, or FIPs, which are designed to bring seafood from wild fisheries to the certified market, with only a promise ...
HIV-1 continues to spread globally. While neither a cure, nor an effective vaccine are available, recent focus has been put on 'treatment-for-prevention', which is a method by which treatment is used to reduce the contagiousness of an infected person. A study published this week in PLOS Computational Biology challenges current treatment paradigms in the context of 'treatment for prevention' against HIV-1.
Sulav Duwal, Max von Kleist and their collaborators develop and employ optimal control theory to compute and assess diagnostic-guided vs. pro-active treatment strategies ...
