(Press-News.org) ITHACA, N.Y. — Using an advanced 3-D time-lapse imaging system, a group of physicists and plant biologists from Cornell University and the Boyce Thompson Institute for Plant Research have discovered how certain plant roots exhibit powerful mechanical abilities while navigating their environment.
The research, published in this week's online Early Edition of Proceedings of the National Academy of Sciences, could eventually assist in breeding crop plants optimized for growth in areas where climate change or over farming has led to difficult soil conditions (study: http://bit.ly/OaG2A5).
The researchers grew Medicago truncatula plants in a transparent gel consisting of two layers – a soft, top layer and a stiff, lower layer. The roots grew straight down until reaching the lower layer, where they began to twist and buckle into spring-like shapes, much like a string begins to curl if it's continuously twisted in one direction.
Combining 3-D movies with measurements and mathematical modeling, the research sheds new light on root growth revealing the role mechanics plays in determining the root shapes. Ultimately, this led to a previously unknown connection between root geometry, growth, and force generation.
"When the roots hit the stiff barrier, growth causes them to buckle like a wire or rod that's been compressed. But by twisting, the buckled roots become helical, allowing the root to push off more gel and get more force at the tip," said Jesse Silverberg, a Cornell graduate student in the Department of Physics and lead researcher for the study.
"Suppose the plant is growing along and finds itself stuck at a layer of clay or tough clump of soil. The root needs an extra force to push through these barriers, and the mathematical model tells us how large of a helix the root needs to grow to do just that. Roughly, the stiffer the barrier, the larger the helix," said Silverberg.
The researchers also used the 3-D technology to discover that 74 percent of the plant roots twisted in a counter-clockwise manner. Silverberg says further research may reveal similar behavior in other plant species.
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3D time-lapse video #1: http://youtu.be/Izm_gge2agU
3D time-lapse video #2: http://youtu.be/vo_glqLFujE
3D time-lapse video #3: http://youtu.be/sSryBCrU92w
Photos: https://cornell.box.com/RootPhotos
Contact Syl Kacapyr for information about Cornell's TV and radio studios.
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DURHAM, N.C. – Hospitals and health systems faced with ongoing shortages of key drugs for cancer and other diseases should develop firm rationing policies based on transparency and fairness, researchers at Duke University Medical Center report.
In a Special Article published online Monday, Sept. 24, 2012 in the Archives of Internal Medicine, the Duke team outlined a policy adopted at Duke Medical Center that established clear-cut rules for apportioning scarce drugs using a hierarchy of clinical need and effectiveness.
Built on similar models that govern some organ donations, ...
CHICAGO – A study of Medicare data suggests there was wide variation in antibiotic prescribing for older patients based on geography and the season in which the prescriptions for the medication were written, according to a report published Online First by Archives of Internal Medicine, a JAMA Network publication.
The overuse of antibiotics is common and can lead to unnecessary spending on prescription medicine, as well as increase the risk for adverse effects and antimicrobial resistance, according to the study background. "Findings on variation in antibiotic prescribing ...
CHICAGO – Compared with rest and sedentary video game play, active video gaming with dancing and boxing were associated with increased heart rate, oxygen uptake and energy expenditure in a study of 18 school children in England, according to a report published Online First by Archives of Pediatrics & Adolescent Medicine, a JAMA Network publication.
Low levels of physical activity have been linked to obesity. Active video game playing compared with traditional sedentary video game playing encourages more movement and could help children increase their physical activity ...
CHICAGO – A medical record review study of 97 patients with the fatal, degenerative brain disorder sporadic Jakob-Creutzfeldt disease (sCJD) suggests that a correct diagnosis of the disease was often delayed by a variety of misdiagnoses, according to a report published Online First by Archives of Neurology, a JAMA Network publication.
The disease is often misdiagnosed because of a variability of early symptoms and signs, a variability in disease duration and a lack of recognition of the condition in the medical community. Often, sCJD is mistaken for other neurodegenerative ...
Improved patient education and ongoing psychological support will help people cope with the psychological distress of having an implanted defibrillator, according to a scientific statement from the American Heart Association.
The statement, published in the American Heart Association journal Circulation, is a comprehensive review of the psychosocial and quality of life for people who receive an implantable cardioverter defibrillator (ICD) to restore normal heart rhythm and prevent sudden cardiac death. It includes recommendations for improved patient care and identifies ...
Prostate cancer is one of the most common cancers in men and early treatment is usually very successful. However, like other cancers, obesity increases the risk of aggressive prostate disease. New research, published in BioMed Central's open access journal BMC Medicine, finds that the fat surrounding the prostate of overweight or obese men with prostate cancer provides a favorable environment to promote cancer growth.
Fat is a generally underrated organ. Not only is it an energy store but it secretes a wide range of growth factors, cytokines and hormones, including leptin ...
PULLMAN, Wash.—A Washington State University researcher has found new evidence that the plastic additive BPA can disrupt women's reproductive systems, causing chromosome damage, miscarriages and birth defects.
Writing in the journal Proceedings of the National Academy of Sciences, WSU geneticist Patricia Hunt and colleagues at WSU and the University of California, Davis, report seeing reproductive abnormalities in rhesus monkeys with BPA levels similar to those of humans. By using an animal with the most human-like reproductive system, the research bolsters earlier work ...
Life in extreme environments – hot acids and heavy metals, for example – can apparently make very similar organisms deal with stress in very different ways, according to new research from North Carolina State University.
One single-celled organism from a hot spring near Mount Vesuvius in Italy fights uranium toxicity directly – by eating the heavy metal and acquiring energy from it. Another single-celled organism that lives on a "smoldering heap" near an abandoned uranium mine in Germany overcomes uranium toxicity indirectly – essentially shutting down its cellular ...
Bladder cancer patients whose tumors express high levels of the protein CD24 have worse prognoses than patients with lower CD24. A University of Colorado Cancer Center study published today in the Proceedings of the National Academy of Sciences shows that CD24 expression may depend on androgens – and that anti-androgen therapies like those currently used to treat prostate cancer may benefit bladder cancer patients.
"This is a major finding – bladder cancer development and spread to other organs depends significantly on CD24, which in turn depends on androgens like testosterone. ...
Cold Spring Harbor, NY – A team of neuroscientists and chemists from the U.S. and China today publish research suggesting that a class of currently used anti-cancer drugs as well as several previously untested synthetic compounds show effectiveness in reversing memory loss in two animal models of Alzheimer's' disease.
CSHL Professor Yi Zhong, Ph.D., who led the research conducted in fruit flies and mice, says he and his colleagues were surprised with their results, which, he stressed, used two independent experimental approaches "the results of which clearly converged." ...
