New hope for powdery mildew resistant barley

New research at the University of Adelaide has opened the way for the development of new lines of barley with resistance to powdery mildew.In Australia, annual barley production is second only to wheat with 7-8 million tonnes a year. Powdery mildew is one of the most important diseases of barley.Senior Research Scientist Dr Alan Little and team have discovered the composition of special growths on the cell walls of barley plants that block the penetration of the fungus into the leaf.The research, by the ARC Centre of Excellence in Plant Cell Walls in the University’s School of Agriculture, Food and Wine in collaboration with the Leibniz Institute of Plant Genetics and Crop Plant Research in Germany, will be presented at the upcoming 5th International Conference on Plant Cell Wall Biology and published in the journal New Phytologist.”Powdery mildew is a significant problem wherever barley is grown around the world,” says Dr Little. “Growers with infected crops can expect up to 25% reductions in yield and the barley may also be downgraded from high quality malting barley to that of feed quality, with an associated loss in market value.”In recent times we’ve seen resistance in powdery mildew to the class of fungicide most commonly used to control the disease in Australia. Developing barley with improved resistance to the disease is therefore even more important.”The discovery means researchers have new targets for breeding powdery mildew resistant barley lines.”Powdery mildew feeds on the living plant,” says Dr Little. “The fungus spore lands on the leaf and sends out a tube-like structure which punches its way through cell walls, penetrating the cells and taking the nutrients from the plant. The plant tries to stop this penetration by building a plug of cell wall material — a papillae — around the infection site. Effective papillae can block the penetration by the fungus.”It has long been thought that callose is the main polysaccharide component of papilla. But using new techniques, we’ve been able to show that in the papillae that block fungal penetration, two other polysaccharides are present in significant concentrations and play a key role.”It appears that callose acts like an initial plug in the wall but arabinoxylan and cellulose fill the gaps in the wall and make it much stronger.”In his PhD project, Jamil Chowdhury showed that effective papillae contained up to four times the concentration of callose, arabinoxylan and cellulose as cell wall plugs which didn’t block penetration.”We can now use this knowledge find ways of increasing these polysaccharides in barley plants to produce more resistant lines available for growers,” says Dr Little.Story Source:The above story is based on materials provided by University of Adelaide. Note: Materials may be edited for content and length.

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Natural plant compounds may assist chemotherapy

Researchers at Plant & Food Research have identified plant compounds present in carrots and parsley that may one day support more effective delivery of chemotherapy treatments.Scientists at Plant & Food Research, working together with researchers at The University of Auckland and the National Cancer Institute of The Netherlands, have discovered specific plant compounds able to inhibit transport mechanisms in the body that select what compounds are absorbed into the body, and eventually into cells. These same transport mechanisms are known to interfere with cancer chemotherapy treatment.The teams’ research, recently published in the European Journal of Pharmacology, showed that falcarinol type compounds such as those found in carrots and parsley may support the delivery of drug compounds which fight breast cancer by addressing the over-expression of Breast Cancer Resistance Protein (BCRP/ABCG2), a protein that leads to some malignant tissues ability to become resistant to chemotherapy.”It’s very exciting work,” says Plant & Food Research Senior Scientist, Dr Arjan Scheepens. “Our work is uncovering new means to alter how the body absorbs specific chemical and natural compounds. Ultimately we are interested in how food could be used to complement conventional treatments to potentially deliver better results for patients.”Story Source:The above story is based on materials provided by New Zealand Institute for Plant and Food Research. Note: Materials may be edited for content and length.

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Unique chromosomes preserved in Swedish fossil

Researchers from Lund University and the Swedish Museum of Natural History have made a unique discovery in a well-preserved fern that lived 180 million years ago. Both undestroyed cell nuclei and individual chromosomes have been found in the plant fossil, thanks to its sudden burial in a volcanic eruption.The well-preserved fossil of a fern from the southern Swedish county of Skne is now attracting attention in the research community. The plant lived around 180 million years ago, during the Jurassic period, when Skne was a tropical region where the fauna was dominated by dinosaurs, and volcanoes were a common feature of the landscape. The fossilised fern has been studied using different microscopic techniques, X-rays and geochemical analysis. The examinations reveal that the plant was preserved instantaneously, before it had started to decompose. It was buried abruptly under a volcanic lava flow.”The preservation happened so quickly that some cells have even been preserved during different stages of cell division,” said Vivi Vajda, Professor of Geology at Lund University.Thanks to the circumstances of the fern’s sudden death, the sensitive components of the cells have been preserved. The researchers have found cell nuclei, cell membranes and even individual chromosomes. Such structures are extremely rare finds in fossils, observed Vivi Vajda.”This naturally leads us to think that there must be more to discover. It isn’t hard to imagine what else could be encapsulated in the lava flows at Korsard in Skne,” said Vivi Vajda.Professor Vajda has carried out the study with two researchers from the Swedish Museum of Natural History, Benjamin Bomfleur and Stephen McLoughlin. The fern belonged to the family Osmundaceae, Royal Ferns. …

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Radiation damage at the root of Chernobyl’s ecosystems

Radiological damage to microbes near the site of the Chernobyl disaster has slowed the decomposition of fallen leaves and other plant matter in the area, according to a study just published in the journal Oecologia. The resulting buildup of dry, loose detritus is a wildfire hazard that poses the threat of spreading radioactivity from the Chernobyl area.Tim Mousseau, a professor of biology and co-director of the Chernobyl and Fukushima Research Initiatives at the University of South Carolina, has done extensive research in the contaminated area surrounding the Chernobyl nuclear facility, which exploded and released large quantities of radioactive compounds in the Ukraine region of the Soviet Union in 1986. He and frequent collaborator Anders Mller of Universit Paris-Sud noticed something unusual in the course of their work in the Red Forest, the most contaminated part of the Chernobyl Exclusion Zone.”We were stepping over all these dead trees on the ground that had been killed by the initial blast,” Mousseau said. “Some 15 or 20 years later, these tree trunks were in pretty good shape. If a tree had fallen in my backyard, it would be sawdust in 10 years or so.”They set out to assess the rate at which plant material decomposed as a function of background radiation, placing hundreds of samples of uncontaminated leaf litter (pine needles and oak, maple and birch leaves) in mesh bags throughout the area. The locations were chosen to cover a range of radiation doses, and the samples were retrieved after nine months outdoors.A statistical analysis of the weight loss of each leaf litter sample after those nine months showed that higher background radiation was associated with less weight loss. The response was proportional to radiation dose, and in the most contaminated regions, the leaf loss was 40 percent less than in control regions in Ukraine with normal background radiation levels.They also measured the thickness of the forest floor in the same areas where samples were placed. They found that it was thicker in places with higher background radiation.The team concluded that the bacteria and fungi that decompose plant matter in healthy ecosystems are hindered by radioactive contamination. They showed a smaller effect for small invertebrates, such as termites, that also contribute to decomposition of plant biomass.According to Mousseau, slower decomposition is likely to indirectly slow plant growth, too, given that the products of decomposition are nutrients for new plants. The team recently reported diminished tree growth near Chernobyl, which he says likely results both from direct radiation effects and indirect effects such as reduced nutrient supply.”It’s another facet of the impacts of low-dose-rate radioactive contaminants on the broader ecosystem,” Mousseau says. …

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Reintroduction experiments give new hope for plant on brink of extinction

A critically endangered plant known as marsh sandwort (Arenaria paludicola) is inching back from the brink of extinction thanks to the efforts of a UC Santa Cruz plant ecologist and her team of undergraduate students.Ingrid Parker, the Langenheim professor of plant ecology and evolution at UC Santa Cruz, got involved in the marsh sandwort recovery effort at the request of the U.S. Fish and Wildlife Service (USFWS). Although it used to occur all along the west coast, from San Diego to Washington state, this wetland plant with delicate white flowers had dwindled to one population in a boggy wetland in San Luis Obispo County. Federal biologists wanted to reintroduce the plant to other locations, but they weren’t sure where it would be likely to thrive.”When you have a species that’s only known from one place, how do you figure out where it could live? We had very little information about its biology that would allow us to predict where it might be successful,” Parker said.Her team, which included undergraduate students and greenhouse staff at UCSC as well as USFWS biologists, propagated cuttings from the last remaining wild population, studied the plant’s tolerance for different soil conditions in greenhouse experiments, and conducted field experiments to identify habitats where the plant could thrive. They published their findings in the April issue of Plant Ecology (available in advance online).Surprisingly, the plants tolerated a much wider range of soil moisture and salinity than biologists had expected. “This really brought home to me the importance of experiments to help guide conservation,” Parker said. “The one place where this species is found in San Luis Obispo County is a freshwater bog where the plants are in standing water. There are so few places like that left in California, we wondered if that’s the only kind of place where it can grow. Instead we found that it actually does better without standing water.”In addition, field studies showed the importance of small-scale habitat variations, according to first author Megan Bontrager. …

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Serpentine ecosystems shed light on nature of plant adaptation, speciation

Plants that live in unusual soils, such as those that are extremely low in essential nutrients, provide insight into the mechanisms of adaptation, natural selection, and endemism. A seminal paper by Arthur Kruckeberg from 1951 on serpentine plant endemism has served as a solid bedrock foundation for future research on the link between natural selection and speciation. A recent article in the American Journal of Botany focuses on how this paper has influenced subsequent research on local adaptation, evolutionary pathways, and the relationship between climate, soils, and endemism.In the latest in a series of AJB Centennial Review papers, AJB Anacker (University of California, Davis) examines the impact that Kruckeberg’s 1951 AJB paper has had on our subsequent understanding of plant evolution and ecology.Kruckeberg’s classic paper reported on reciprocal transplant experiments, in which he made several generalizations about plant competition, local adaptation, and speciation. Kruckeberg showed that the strong selective pressures of serpentine soils — characterized by low amounts of essential nutrients and water, and high in heavy metals — can lead to the formation of soil ecotypes (genetically distinct plant varieties), representing a possible first step in the evolution of serpentine endemism (e.g., plants that are only found on serpentine type soils). These important initial findings spurred subsequent research on determining plant traits (from molecular to organismal) that underlie serpentine adaptation.Anacker draws attention to a second significant contribution of Kruckeberg’s paper — researching the historic origins of endemic species, such as those found in serpentine soils. Anacker explains that endemic species are thought to originate in two ways: neoendemics are species that have formed relatively recently via nearby progenitor taxa, and paleoendemics are species that formed following habitat-specific population extirpation. Kruckeberg viewed serpentine ecotypes as representing the first step along the path of paleoendemism. While this stimulated much research in this area, Anacker points out that several serpentine endemics appear to have arisen from nearby progenitor taxa, and thus the neoendemic pathway is also likely important.Interestingly, Kruckeberg’s experiments also showed that many serpentine ecotypes actually performed better on the non-serpentine soils than on serpentine soils, which begs the question of why serpentine-adapted plants are not also found on non-serpentine soils. Anacker points out that Kruckeberg was one of the first to indicate that competition may play a key role in serpentine specialization. He also highlights recent research indicating that serpentine species are typically slow-growing stress tolerators rather than fast-growing competitive dominants, and their adaptations for being more drought-tolerant puts them at a disadvantage in soils where water and nutrients are not limiting.While serpentine ecosystems are special and unique environments, Kruckeberg and subsequent researchers have shown how important these systems are for shedding light on broader aspects of plant ecology and evolution.The 1951 paper can be accessed online at: http://www.jstor.org/discover/10.2307/2438248?uid=3739448&uid=2&uid=3737720&uid=4&sid=21103728973903Story Source:The above story is based on materials provided by American Journal of Botany. …

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Rapeseed-based animal feed cuts greenhouse gases by up to 13 per cent

The use of rapeseed cake in the production of livestock feed cuts methane and carbon dioxide emissions by up to 13%, according to the initial results of the research carried out by Neiker-Tecnalia within the framework of the Life-Seed Capital project. Specifically, the incorporation of this oilseed plant into animal food cuts methane emissions by between 6% and 13% and carbon dioxide emissions by between 6.8% and 13.6%.The introduction of this oilseed preparation into the diet of ruminants also improves efficiency in the use of digestible organic matter by between 4.4% and 10.1% and cuts the fermentation of the diet by between 6.2% and 11.8%, without adversely affecting its digestibility for this reason. Rapeseed cake, also known as ‘oil cake’, is a by-product obtained after pressing the plant to extract its oil.The Life-Seed Capital project is being funded by the European Union through its Life+ program and is being led by the Basque Institute for Agricultural Research and Development, Neiker-Tecnalia, and by the Multidisciplinary Centre for Industry Technologies CEMITEC. The project seeks to take advantage of rapeseed crops to improve agricultural productivity and, at the same time, to cut greenhouse gas emissions.The advantages of using this plant start from its use as a rotation crop, because it is capable of increasing cereal productivity and improving soil structure. Once it has been harvested, rapeseed can be used as a biofuel and added to diesel in varying proportions after simple cold pressing. A waste product in this process is used at the same time to produce animal feed with the resulting cost-cutting for farmers and greater efficiency in the emission of greenhouse gases.Story Source:The above story is based on materials provided by Basque Research. Note: Materials may be edited for content and length.

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After the saffron spice DNA

Researchers at the UPM and the University of Tor Vegata of Roma have proposed a new technique that allows the detection of adulterated saffron spice.A collaborative research between Universidad Politcnica de Madrid (UPM) and the University of de Tor Vegata has studied the DNA of the saffron spice through the analysis of its genetic code. The use of this technique has clarified aspects of the genetic variability of this species, which has allowed the design of a system that can discriminate and certify the authenticity of saffron spice to avoid cases of adulteration.Saffron (Crocus sativus L.) is sterile plant species of bulbous herb with purple colored flowers whose origin is still unknown. The dry stigmas of the Crocus sativus L. are commonly known as saffron, which is a cultivated plant with a gastronomical reputation that dates back from ancient times. In fact, it is only vegetatively propagated by bulbs due to its incapacity of producing fertile pollen and for this reason, seeds.The plant blooms just once a year and the harvest of stigmas are made by manual selection in a very short amount of time. For this reason, saffron spice is the most expensive spice in the world.This research has used a DNA barcode technique to define different species and saffron spice crop fields. For this reason, researchers have analyzed samples of various species of Crocus, both Italians and Spanish ones, including species from different origins of cultivated saffron spice. As a result of this study, researchers found some aspects of the phylogeny of this gender, particularly the genetic drift of Crocus sativus.Numerous morphological studies support the theory that saffron spice was originated from evolution or hybridization of other saffron species, especially C. thomasii, C. hadriaticus and C. …

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Smoke in the water: Understanding effects of smoke compounds on seed germination

Although seemingly destructive, wildfires help to maintain biodiversity and are an important element of many ecosystems throughout the world. Not only do fires discourage non-native and invasive species from becoming established, but the quick release of nutrients, heat, and compounds found in ash and smoke play an important role in the life cycle of the native flora. For plants that are adapted to ecosystems where fire is a regular occurrence — such as savannas, grasslands, and coniferous forests — exposure to fire may initiate seed germination or enhance plant growth.Recent research has focused on the effects of smoke. As plant tissue is burned, numerous compounds are released, some of which have been found to break seed dormancy and stimulate germination. In a new study published in the March issue of Applications in Plant Sciences, scientists at Eastern Illinois University have developed a novel system to produce smoke solutions to further investigate the importance of smoke compounds such as butenolides and cyanohydrins in seed germination and seedling growth.”Because many of the identified compounds are known to be water soluble, using a smoke solution is a convenient alternative to direct fumigation of seeds,” explains Dr. Janice Coons, lead author of the study.The new system utilizes a bee smoker, heater hose, and water aspirator. Water-soluble compounds are dissolved by bubbling smoke through water contained in a flask. This setup is inexpensive and much more compact than previous systems, allowing for the production of smaller volumes of smoke solution within a small space, such as a fume hood.This new apparatus increases the concentration of smoke compounds in the solution and allows for greater control of variables. For example, different species of plants contain different compounds, which may have different effects on seed germination. “Native species often require special conditions to break seed dormancy,” explains Coons. …

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Nitrogen-tracking tools for better crops, less pollution

As every gardener knows, nitrogen is crucial for a plant’s growth. But nitrogen absorption is inefficient. This means that on the scale of food crops, adding significant levels of nitrogen to the soil through fertilizer presents a number of problems, particularly river and groundwater pollution. As a result, finding a way to improve nitrogen uptake in agricultural products could improve yields and decrease risks to environmental and human health.Nitrogen is primarily taken up from the soil by the roots and assimilated by the plant to become part of DNA, proteins, and many other compounds. Uptake is controlled by a number of factors, including availability, demand, and the plant’s energy status. But there is much about the transport proteins involved in the process that isn’t understood. New work from Carnegie’s Cheng-Hsun Ho and Wolf Frommer developed tools that could help scientists observe the nitrogen-uptake process in real time and could lead to developments that improve agriculture and the environment. It will be published by eLife on March 11 and is already available online.Frommer had previously developed technology to spy on transport protein activity by using fluorescent tags in a cell’s DNA to monitor the structural rearrangements that a transporter undergoes as it moves its target molecule. They tailored this technology to five nitrogen transport targets to monitor the nitrogen uptake and assimilation process. “We engineered these sensors to monitor the activity and regulation of suspected nitrogen transporters in living plant roots, which otherwise are impossible to study,” Frommer said. …

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Evidence mixed on the usefulness of echinacea for colds

For people seeking a natural treatment for the common cold, some preparations containing the plant Echinacea work better than nothing, yet “evidence is weak,” finds a new report from The Cochrane Library. The evidence review revealed no significant reductions in preventing illness, but didn’t rule out “small preventive effects.”The six authors conducted reviews on this subject in 1998, 2006 and 2008 and wanted to do an update to include several new trials conducted since then. “We’ve been doing this for so long and are very familiar with past research — which has been mixed from the very beginning,” said author Bruce Barrett, M.D., Ph.D. in the department of family medicine at the University of Wisconsin in Madison.The research team reviewed 24 randomized controlled trials to determine whether Echinacea was a safe and effective cold prevention and treatment. Trials included 4631 participants and 33 preparations, along with placebo. Echinacea products studied in these trials varied widely according to characteristics of three different plant species, the part of the plant used and method of manufacturing.People who get colds spend $8 billion annually on pharmaceutical products, including supplements such as Echinacea, Barrett noted. The authors’ meta-analyses suggest that at least some Echinacea preparations may reduce the relative risk of catching a cold by 10 to 20 percent, a small effect of unclear clinical significance. The most important recommendation from the review for consumers and clinicians is a caution that Echinacea products differ greatly and that the overwhelming majority of these products have not been tested in clinical trials.Barrett added that “it looks like taking Echinacea may reduce the incidence of colds. For those who take it as a treatment, some of the trials report real effects — but many do not. Bottom line: Echinacea may have small preventive or treatment effects, but the evidence is mixed.””The paper does support the safety and efficacy of Echinacea in treating colds and highlights the main issue of standardizing herbal medicines,” commented Ron Eccles, Ph.D., director of the Common Cold Centre & Healthcare Clinical Trials at Cardiff University’s School of Biosciences in Wales.Story Source:The above story is based on materials provided by Health Behavior News Service, part of the Center for Advancing Health. …

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How evolution shapes the geometries of life

Why does a mouse’s heart beat about the same number of times in its lifetime as an elephant’s, although the mouse lives about a year, while an elephant sees 70 winters come and go? Why do small plants and animals mature faster than large ones? Why has nature chosen such radically different forms as the loose-limbed beauty of a flowering tree and the fearful symmetry of a tiger?These questions have puzzled life scientists since ancient times. Now an interdisciplinary team of researchers from the University of Maryland and the University of Padua in Italy propose a thought-provoking answer based on a famous mathematical formula that has been accepted as true for generations, but never fully understood. In a paper published the week of Feb. 17, 2014 in the Proceedings of the National Academy of Sciences, the team offers a re-thinking of the formula known as Kleiber’s Law. Seeing this formula as a mathematical expression of an evolutionary fact, the team suggests that plants’ and animals’ widely different forms evolved in parallel, as ideal ways to solve the problem of how to use energy efficiently.If you studied biology in high school or college, odds are you memorized Kleiber’s Law: metabolism equals mass to the three-quarter power. This formula, one of the few widely held tenets in biology, shows that as living things get larger, their metabolisms and their life spans increase at predictable rates. Named after the Swiss biologist Max Kleiber who formulated it in the 1930s, the law fits observations on everything from animals’ energy intake to the number of young they bear. It’s used to calculate the correct human dosage of a medicine tested on mice, among many other things.But why does Kleiber’s Law hold true? …

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Promise for castor crop planting in Florida

Castor, grown in Florida during World War II and currently considered as a component for military jet fuel, can be grown here again, using proper management techniques, a new University of Florida study shows.Those techniques include spacing plants properly and using harvest aids to defoliate the plant when it matures.Growers in the U.S. want to mechanically harvest castor, which is typically hand-picked in other parts of the world, the researchers said. Among other things, the UF/IFAS study evaluated whether the plant would grow too tall for mechanical harvesting machines.Castor oil is used in paints, lubricants and deodorants, among other industrial products, said David Campbell, a former UF agronomy graduate student and lead author of the study. It has not been grown in the U.S. since 1972, because the federal government ceased giving price supports, the study says.At UF research units in Citra and Jay, scientists tested Brigham and Hale, two types of castor that were bred in an arid part of west Texas near Lubbock in 1970 and 2003, respectively. These cultivars are shorter than castor found in the wild, said Diane Rowland, an associate professor of agronomy at UF’s Institute of Food and Agricultural Sciences, and Campbell’s faculty adviser.Scientists tried to control the growth of the plants even more by spraying them with a chemical, she said. Even though the crop didn’t respond to the chemicals, it did not grow taller than expected. So it appears these types of castor can be harvested mechanically, she said.While yields were lower than those reported in Texas research trials in 1993, results are promising for Florida.“We were concerned that, in this environment, with all the moisture and the good growing conditions, that it would grow too tall. But it didn’t,” Rowland said. “So it shows that shorter genetic types will still work, without the chemical application. …

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Oil composition boost makes hemp a cooking contender

Scientists at the University of York today report the development of hemp plants with a dramatically increased content of oleic acid. The new oil profile results in an attractive cooking oil that is similar to olive oil in terms of fatty acid content having a much longer shelf life as well as greater heat tolerance and potentially more industrial applications.Researchers in the Centre for Novel Agricultural Products (CNAP) in the Department of Biology at York say that high oleic acid varieties are a major step towards developing hemp as a commercially attractive break crop for cereal farmers. The research is published in Plant Biotechnology Journal.Using fast-track molecular plant breeding, the scientists selected hemp plants lacking the active form of an enzyme involved in making polyunsaturated fatty acids. These plants made less poly-unsaturated fatty acids and instead accumulated higher levels of the mono-unsaturated oleic acid. The research team used conventional plant breeding techniques to develop the plants into a “High Oleic Hemp” line and higher oleic acid content was demonstrated in a Yorkshire field trial.Oil from the new line was almost 80 per cent oleic acid, compared with typical values of less than 10 per cent in the standard hemp line. This high mono-unsaturated/low poly-unsaturated fatty acid profile increases the oil’s thermal stability and oil from the new line was shown to have around five times the stability of standard hemp oil. This not only makes the oil more valuable as a cooking oil but also increases its usefulness for high temperature industrial processes.As oilseed rape faces declining yields and increasing attacks from pest and disease, UK farming needs another break crop to ensure the sustainability of its agriculture and maintain cereal yields. An improved hemp crop, yielding high quality oil would provide an excellent alternative. Hemp is a low-input crop and is also dual-purpose, with the straw being used as a fibre (for bedding, composites and textiles), for biomass and as a source of high value waxes and secondary metabolites.Professor Ian Graham, from CNAP, said: “The new line represents a major improvement in hemp as an oil crop. Similar developments in soybean and oilseed rape have opened up new markets for these crops, due to the perceived healthiness and increased stability of their oil.”In 2014 field trials of the new High Oleic Hemp are being rolled out across Europe in order to establish agronomic performance and yield under a range of environmental conditions in advance of launching a commercial crop.Story Source:The above story is based on materials provided by University of York. …

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Substance in photosynthesis was in play in ancient, methane-producing microbes

An international team of researchers led by scientists at Virginia Tech and the University of California, Berkeley has discovered that a process that turns on photosynthesis in plants likely developed on Earth in ancient microbes 2.5 billion years ago, long before oxygen became available.The research offers new perspective on evolutionary biology, microbiology, and the production of natural gas, and may shed light on climate change, agriculture, and human health.”By looking at this one mechanism that was not previously studied, we will be able to develop new basic information that potentially has broad impact on contemporary issues ranging from climate change to obesity,” said Biswarup Mukhopadhyay, an associate professor of biochemistry at the Virginia Tech College of Agriculture and Life Sciences, and the senior author of the study. He is also a faculty member at the Virginia Bioinformatics Institute. Plant and microbial biology professor emeritus Bob B. Buchanan co-led the research and co-authored the paper.The findings were described this week in an early online edition of the Proceedings of the National Academy of Sciences.This research concerns methane-forming archaea, a group of microbes known as methanogens, which live in areas where oxygen is absent. Methane is the main component of natural gas and a potent greenhouse gas.”This innovative work demonstrates the importance of a new global regulatory system in methanogens,” said William Whitman, a professor of microbiology at the University of Georgia who is familiar with the study, but not connected to it. “Understanding this system will provide the tools to use these economically important microorganisms better.”Methanogens play a key role in carbon cycling. When plants die, some of their biomass is trapped in areas that are devoid of oxygen, such as the bottom of lakes.Methanogens help convert the residual biological material to methane, which other organisms convert to carbon dioxide — a product that can be used by plants.This natural process for producing methane forms the basis for treating municipal and industrial wastes, helps reduce pollution, and provides methane for fuel. The same process allows natural gas production from agricultural residues, a renewable resource.Methanogens also play an important role in agriculture and human health. They live in the digestive systems of cattle and sheep where they facilitate the digestion of feed consumed in the diet.Efforts to control methanogens in specific ways may improve feed utilization and enhance the production of meat and milk, researchers say.Methanogens are additionally a factor in human nutrition. The organisms live in the large intestine, where they enhance the breakdown of food. …

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Grasshoppers are what they eat: New method to extract plant DNA from grasshopper guts sheds light on plant-insect interactions

Grasshoppers may be small, but the damages they are causing to the U.S. agriculture industry are anything but. Every year, they feed on crops and on rangelands needed for raising livestock, costing landowners millions of dollars. Although they pose a major threat, grasshopper populations play a positive role in cycling nutrients from decomposing plant matter back into the soil. A new method to investigate their feeding patterns could be the key to a better understanding of the impact of grasshoppers on plant communities.”The main problem with current control methods is the damage done to non-target plant and insect species,” says University of Cincinnati researcher Alina Avanesyan, who developed the new protocol while studying grasshopper leaf tissue consumption. “Accurately determining the feeding preferences of grasshoppers can help us to understand the magnitude of plant damage, and consequently, whether or not control of grasshoppers is needed in a given area.”The method recovers high-quality DNA of ingested plant tissue from grasshopper guts. This plant DNA offers valuable information about grasshopper diets because it holds more data than what can be observed by the naked eye. Scientists can use it to compare specific feeding patterns between different grasshopper species and uncover behaviors that might lead to intensive crop damage in certain areas. A detailed description of the dissection and DNA extraction, including a video illustrating the dissection technique, can be viewed in the February issue of Applications in Plant Sciences.According to Avanesyan, “With this protocol, a researcher can focus on a variety of research questions, such as detecting plant-insect interactions, determining how long the food has been digested, estimating the prevalence of different plants in insect guts, exploring the sequence of multiple plant species consumed, and inferring feeding preferences.”The protocol begins with a basic dissection kit used to isolate the grasshopper guts. A DNA extraction is then performed on the gut components, which results in a combination of grasshopper and plant DNA. …

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Herbicides may not be sole cause of declining plant diversity

The increasing use of chemical herbicides is often blamed for the declining plant biodiversity in farms. However, other factors beyond herbicide exposure may be more important to species diversity, according to Penn State researchers.If herbicides are a key factor in the declining diversity, then thriving species would be more tolerant to widely used herbicides than rare or declining species, according to J. Franklin Egan,research ecologist, USDA-Agricultural Research Service.”Many ecotoxicology studies have tested the response of various wild plant species to low dose herbicide exposures, but it is difficult to put these findings in context,” said Egan. “Our approach was to compare the herbicide tolerances of plant species that are common and plant species that are rare in an intensively farmed region. We found that rare and common plant species had roughly similar tolerances to three commonly used herbicides.”This could mean that herbicides may not have a persistent effect in shaping plant communities.The researchers, who report their findings in the online version of the journal Environmental Toxicology and Chemistry, said that over the past several decades, in the same time that the use of herbicides was on the rise, other factors such as the simplification of crop rotations, segregation of crop and livestock and increasing mechanization have also been rapidly evolving. In addition, the clearing of woodlots, hedgerows, pastures and wetlands to make way for bigger fields has continued apace and resulted in habitat loss.While the findings are preliminary, the approach could be effective in clarifying the implications of herbicide pollution for plant conservation, Egan said.”These findings are not an invitation to use herbicides recklessly,” he said. “There are many good reasons to reduce agriculture’s reliance on chemical weed control. But, for the objective of plant species conservation, other strategies like preserving farmland habitats including woodlots, pastures and riparian buffers may be more effective than trying to reduce herbicide use.”Egan worked with David Mortensen, professor of weed and applied plant ecology, and Ian Graham, an undergraduate student in plant science.Story Source:The above story is based on materials provided by Penn State. The original article was written by Jennifer Lynch. Note: Materials may be edited for content and length.

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Well-watered citrus tested in cold-acclimating temperatures

Commercial citrus growers are often challenged by environmental conditions in winter, including low seasonal rainfall that is typical in many citrus growing regions. Growers must rely on irrigation to sustain citrus crops through dry winters, so understanding how to determine citrus irrigation needs is critical for successful operations.Authors of a study published in HortScience noted that current methods used to determine moisture needs for citrus are limited, in that they do not account for effects of cold acclimation on water requirements. “Evidence suggests that at least some changes in plant water deficits occur as a result of cold temperatures and not dry soil,” noted Robert Ebel, lead author of the study. “Changes in citrus water relations during cold acclimation and independent of soil moisture content are not well understood. Our study was conducted to characterize changes in plant relations of citrus plants with soil moisture carefully maintained at high levels to minimize drought stress.”Ebel and his colleagues conducted two experiments–the first in Immokalee, Florida, using potted sweet orange, and the second in Auburn, Alabama, using Satsuma mandarin trees. The citrus plants were exposed to progressively lower, non-freezing temperatures for 9 weeks. During the experiments trees were watered twice daily–three times on the days data were collected–to minimize drought stress.Results of the experiments showed that soil moisture was higher for plants in the cold compared to plants in the warm chamber, and results showed that cold temperatures promoted stomatal closure, higher root resistance, lower stem water potential, lower transpiration, and lower stem water potential. Leaf relative water content was not different for cold-acclimated trees compared with the control trees. The key to minimizing drought stress, the scientists found, was carefully maintaining high soil moisture contents throughout the experiments, especially on the days that the measurements were performed.”Our modern understanding of plant water relations has mainly evolved from studying growing plants at warm temperatures and in soils of varying moisture contents,” Ebel explained. “However, this study demonstrates that those relationships are not consistent for citrus trees exposed to cold-acclimating temperatures.”The authors added that the study findings could have implications for commercial citrus growers who currently use traditional measures of determining irrigation scheduling during winter months.The complete study and abstract are available on the ASHS HortScience electronic journal web site: http://hortsci.ashspublications.org/content/48/10/1309.abstractStory Source:The above story is based on materials provided by American Society for Horticultural Science. …

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Model plant misled scientists about multicellular growth

Oct. 22, 2013 — Scientists have misunderstood one of the most fundamental processes in the life of plants because they have been looking at the wrong flower, according to University of Leeds researchers.Arabidopsis thaliana — also known as thale cress or mouse-ear cress — grows abundantly in cracks in pavements all over Europe and Asia, but the small white flower leads a second life as the lab rat of the plant world.It has become the dominant “model plant” in genetics research because of its simple genetics and ease of use in a research environment. Thousands of trays of the humble weed are cultivated in laboratories across the world, but it turns out they may actually contain a rather oddball plant.A study by researchers at the University of Leeds found that Arabidopsis thaliana was exceptional in not having a “censorship” protein called SMG1.SMG1 was known to play a vital role in the growth of animals as multicellular organisms, but scientists thought that plants built their complex life fundamentally differently. That conclusion, it turns out, was built on a dummy sold by Arabidopsis thaliana.Professor Brendan Davies from the University of Leeds’ School of Biology, who led the study, said: “Everybody thought that this protein was only in animals. They thought that because, basically, most of the world studies one plant: Arabidopsis thaliana.”Gene expression — the process by which the information from a genome is converted into the differentiated cells that make up complex life — relies on processes that turn genes on, when their genetic messages are required, and off when they are not.”Switching genes on and off is really what life is about. If you can’t do that, you can’t have life,” said Professor Davies. “There are various ways this is done, but one way in more complex life such as animals and plants is through a sort of ‘censorship’ process. The system looks at the messages that come out of the nucleus and effectively makes a judgement on them. It says ‘I am going to destroy that message now’ and intervenes to destroy it before it takes effect.”Scientists know that this “censorship” process — called Nonsense Mediated mRNA Decay (NMD) — is used by both plants and animals, but thought the two types of organism did it in different ways.Because Arabidopsis thaliana does not have SMG1, which plays a key role in triggering the censorship system in animals, scientists had concluded that SMG1 was not present in any plant.However, the Leeds researchers discovered that the plant that has established itself as the standard reference plant for all of biology is in fact an anomaly.”We have found that SMG1 is in every plant for which we have the genome apart from Arabidopsis and we have established that it is being used in NMD. Rather than being just in animals, we are suggesting that the last common ancestor of animals and plants had SMG1,” Professor Davies said.The study also found SMG1 in Arabidopsis lyrata, a close relative of Arabidopsis thaliana, which suggests that the missing protein has been lost relatively recently in evolutionary time, perhaps in the last 5-10 million years.The next key question for researchers is to explain how organisms without SMG1, such has funghi and Arabiposis thaliana, work without the protein.As for Arabidopsis thaliana, it may not have met its Waterloo just yet. …

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Key genes for increasing oil content in plant leaves identified

Related Links Plant Cell paper: Dual Role for Phospholipid:Diacylglycerol Acyltransferase: Enhancing Fatty Acid Synthesis and Diverting Fatty Acids from Membrane Lipids to Triacylglycerol in Arabidopsis Leaves [http://www.plantcell.org/content/early/2013/09/26/tpc.113.117358.abstract] Share this story on Facebook, Twitter, and Google: Other social bookmarking and sharing tools: | Story Source: The above story is based on materials provided by Brookhaven National Laboratory. Note: Materials may be edited for content and length. For further information, please contact the source cited above. Journal References: Jilian Fan, Chengshi Yan, Changcheng Xu. Phospholipid:diacylglycerol acyltransferase-mediated triacylglycerol biosynthesis is crucial for protection against fatty acid-induced cell death in growing tissues of Arabidopsis. The Plant Journal, 2013; DOI: 10.1111/tpj.12343 Jilian Fan, Chengshi Yan, Xuebin Zhang and Changcheng Xu1. Dual Role for Phospholipid:Diacylglycerol Acyltransferase: Enhancing Fatty Acid Synthesis and Diverting Fatty Acids from Membrane Lipids to Triacylglycerol in Arabidopsis Leaves[C][W]. The Plant Cell, 2013 DOI: 10.​1105/​tpc.​113.​117358 Need to cite this story in your essay, paper, or report? Use one of the following formats: APA MLA Note: If no author is given, the source is cited instead. enlargeClick on the image to download a high-resolution version. …

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