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News Article | April 26, 2017
Site: www.nature.com

Plant biologist Krishna Niyogi opens the doors of growing cabinets in his lab at the University of California, Berkeley, revealing rows of tobacco and Arabidopsis plants. Under the warm solar lamps, vibrant green algae thrives in rotating flasks and streaked on petri dishes. For the past 20 years or so, Niyogi has been using these plants to study photosynthesis, mutating one gene at a time to uncover the molecular mechanisms behind plants' responses to shifting light levels. The green world inside the cabinets may seem distant from the reality of growing maize (corn) in Iowa or rice in Cambodia, but think again. Last November, Niyogi and his colleagues showed that engineering photosynthesis can improve crop yields in field-grown tobacco plants (Nicotiana tabacum). The researchers are now translating their modifications to food crops. Mindful of the growing global population, non-profit organizations and governments around the world are investing in research to optimize photosynthesis in the hope of improving the yield of crops such as rice, wheat and cowpeas. “Photosynthesis is a bit of an underachiever,” says Jeremy Harbinson, a plant scientist at Wageningen University in the Netherlands. Photosynthesis is inefficient and, despite it being one of the best understood processes in plants, it hasn't been exploited by agronomists to boost crop production, Harbinson explains. While researchers, such as Niyogi, are engineering plants to use sunlight more efficiently, others are working to improve the reactions that capture carbon dioxide or, even more ambitiously, reinvent a plant's metabolism and anatomy. During the middle of the last century, amid warnings of famines, scientists made a concerted effort to modernize agriculture. As part of the green revolution, agronomists used conventional breeding techniques to improve yields, producing plants with shorter stalks, for example, that focus their energy on making more seeds instead. They also encouraged the use of fertilization, irrigation and pest-control methods. These advances meant global production of wheat, rice and maize doubled from around 1 billion tonnes of grain in 1960 to 2 billion tonnes in 2000. A food-supply crisis was averted. The prospect of world hunger looms again, however. To feed 2050's expected population of 9.7 billion people, the Food and Agriculture Organization (FAO) of the United Nations estimates that global agricultural production will have to rise by about 50%, and double in developing countries, assuming levels of food loss and waste do not change. But the techniques that have increased yields since the 1960s may have hit a ceiling. In wheat and rice in particular, plant biologists are seeing limited improvements. “We've been living off those gains for 50 years,” says Robert Furbank, director of the Australian Research Council Centre of Excellence for Translational Photosynthesis in Acton. “We have to look at radical solutions.” Reducing food loss and waste (see page S6), and making more-sustainable dietary choices (see page S18) will help. But increasing the potential yield of crops to produce more food without using extra land, water or fertilizer would be a powerful boost to ensuring people have access to enough food. The hope is that with genetic modification of photosynthesis we will enter a new era of yield improvements. Photosynthesis is the chain of metabolic reactions through which plants convert energy from the Sun, CO and water into the molecules they need. The process converts only about 5% of the energy that plants receive into biomass. “You would think a billion years of evolution would have optimized photosynthesis by now,” says Niyogi, but things aren't so simple. For one thing, cultivated crops face different limiting factors to wild plants. “In nature, plants are usually limited by drought stress, nutrients and pathogens,” he says. But modern farming methods and tools such as irrigation, fertilizer and pesticides have lessened these challenges, affording cultivated crops the luxury of bumping up against the inefficiencies of light absorption. Niyogi's research centres on a fundamental process called photoprotection. High levels of sunlight can damage plant cells, so to protect themselves they make pigments that temporarily deflect excess energy when sunlight is too bright — a botanical sunscreen. When the light levels shift, perhaps because of the movement of leaves that shade others or a change in cloud cover, plant cells ramp photosynthesis back up — but it takes a few minutes. In densely planted crops, where a canopy of leaves creates dynamic patterns of light and shade, a lot of productive time is lost to this photoprotection lag. Niyogi's research focuses on a photoprotection mechanism called non-photochemical quenching (NPQ), which reduces yield by an estimated 20%. His group has had promising results from the upregulation of three genes in tobacco involved in two forms of NPQ that include the protective pigment zeaxanthin. But positive results in the lab are no guarantee of success in a field crop. It can be difficult to get plants to stably express new genes over multiple generations. And of course, field conditions can vary widely from the controlled environment inside growth cabinets. Niyogi's team is part of a multi-institution project — called Realizing Increased Photosynthetic Efficiency (RIPE) — to increase the yield of food crops in developing countries through photosynthesis. As part of the programme, the Berkeley researchers worked with plant biologist Stephen Long, who directs the wider RIPE project, and his team at the University of Illinois at Urbana–Champaign to do field tests of the engineered light-handling mechanism in tobacco. Tobacco is a good model for studying photoprotection because it has a dense canopy of leaves, like maize. RIPE's computer models, which simulate the reactions of photosynthesis, predicted a 20% improvement in yield for tobacco plants with genetically altered NPQ pathways. That's a big change — an improvement of just a few per cent achieved without upping the pressure on land, water or fertilizer would make a significant difference to farmers. Because this kind of research can be difficult to translate to field trials, when the researchers measured the dry weight, and saw the tobacco yield had been boosted by 15%1, they were delighted. “Yes! We got more!” Long says. They are now planning to test whether the photoprotection boost works in cowpea (Vigna unguiculata), a major source of protein in sub-Saharan Africa, in partnership with researchers at the Commonwealth Scientific and Industrial Research Organisation in Australia and cowpea breeders in West Africa. And in Illinois, the researchers are translating the work to rice. Tinkering with photoprotection is not the only way to improve plants' use of light energy. Anastasios Melis, a plant biologist at the University of California, Berkeley, is working on reducing the amount of the pigment chlorophyll inside chloroplasts, plants' photosynthetic organelles. Melis knows that this sounds counter-intuitive. But consider the way in which a canopy of densely planted crops shades many of the leaves below, he says. More-transparent leaves with less chlorophyll will allow more light to pass through to lower leaves — improving the productivity of the plant as a whole. Researchers are also studying the infrared-absorbing chlorophylls made by some types of photosynthetic cyanobacteria2. Infrared radiation is normally considered to be outside the range that can be used by plants for photosynthesis. If scientists can map out the details of how bacterial chlorophylls are produced, and integrate them into crops, the number of available photons could increase by about 19%, allowing the modified plants to capture more solar energy. “We cannot change the intensity of the sunlight,” says Melis. “We just have to make better use of it.” The solar energy that plants capture is used to make chemical energy inside the cell. This is then used to fix CO and make sugars. This second stage, called the Calvin cycle, could also be made more efficient. Rubisco is one of the most important enzymes in the Calvin cycle, but the CO fixing enzyme is prone to errors. “Every fourth turnover, it fixes an oxygen molecule instead of CO ,” explains Donald Ort, a plant biologist for the US Department of Agriculture who is based at the University of Illinois at Urbana–Champaign. This chemical error, known as photorespiration, generates a toxic compound called glycolate that plants must break down. When photosynthetic cells first evolved, there was very little oxygen in the atmosphere, so the fact that rubisco couldn't always distinguish oxygen from CO wasn't a problem. Researchers think that by the time oxygen levels were high enough to be a problem, the enzyme was too established and complex to be improved through evolution. Instead, plants make rubisco in large quantities so there is always enough to fix the CO needed. The enzyme is thought to be the most abundant on Earth. Although higher levels of CO in the atmosphere boost photosynthesis, human activities that increase the level of CO will not improve rubisco's odds. The enzyme makes more mistakes at higher temperatures, and plant scientists expect that photorespiration will increase as a result of rising global temperatures — to the detriment of crop yields. For many years, researchers were uncertain whether there was much variation in rubisco, says Elizabete Carmo-Silva, a plant scientist at Lancaster University, UK. But improvements in technology that allows photosynthetic phenotypes to be measured in the field have shown that this isn't true. Carmo-Silva's group is studying rubisco and rubisco activase (which helps restore the carbon-fixing enzyme after it makes a mistake) in wheat strains. The work is ongoing, but the team has already found variants of these enzymes that recover more quickly than typical rubisco after fixing oxygen. These variants could be bred into the germplasm, the genetic material that's used to develop seeds, she says (see page S8). Ort is focused on streamlining the reactions that plants use to break down glycolate. These type of reactions use a lot of energy and require chemical intermediates to be shuttled between chloroplasts, mitochondria and organelles called peroxisomes. “This lowers the efficiency of photosynthesis by about 30 or 40% — it's huge,” says Ort. Organisms, such as the bacterium Escherichia coli, have more-efficient reaction pathways for metabolizing glycolate than the complex pathways that evolved in plants. When researchers tried to introduce this bacterial mechanism into Arabidopsis, they found that photosynthesis was boosted only modestly3. Ort suspects that this is because plant cells were still shipping glycolate out of the chloroplast even with the introduction of the improved chemical pathway. Ort has developed tobacco plants with chloroplasts that lack glycolate transporters, and so are forced to metabolize the compound in that organelle using the more-efficient pathway. Preliminary results suggest that these plants had a 20–30% increase in biomass. Before submitting the work for publication, Ort plans to replicate the results in a second field experiment this year. Although plants haven't developed an alternative to rubisco, a more-efficient form of photosynthesis has independently evolved more than 60 times. C photosynthesis, in which the first step involves producing a four-carbon compound instead of a three-carbon one, is about 50% more efficient than the C process because it uses a more-effective enzyme to capture CO . This is especially true for plants living in dry, hot conditions, says Jane Langdale, a plant biologist at the University of Oxford, UK. Langdale is part of the C Rice Project, which aims to transform rice from a C into a C plant. The project was conceived in 1999 by John Sheehy, a plant physiologist at the International Rice Research Institute (IRRI) in Los Baños, Philippines, and the project's scientists would be the first to admit that their goal is ambitious. To make rice into a C plant, researchers must endow it not only with new metabolic networks, but also with a new anatomy. During the initial phases of the project, scientists focused on finding the genes responsible for C metabolism. They then added these genes to a strain of rice one at a time. In the modified rice, only about 5% of CO enters the more-efficient C pathway, says plant biologist Paul Quick at the IRRI, who led this phase of work. “We won't be able to get the benefit of the C pathway until we have the anatomy,” he says. Understanding how to build the leaf anatomy is the current phase of the project. Photosynthetic cells in the leaves of C plants are arranged around the veins in a circular pattern called Kranz anatomy (see 'Shape of things to come'). Instead of using rubisco, bundle sheath cells in this ring use the enzyme phosphoenolpyruvate carboxylase, which doesn't bind oxygen, to capture CO in a four-carbon compound. The compound is then shuttled into a second type of cell, called a mesophyll, where it is converted back to CO and fixed by rubisco. The CO concentration is much higher in C mesophyll cells, and so the rate of photorespiration is much lower. Despite the additional conversion steps and the need to move compounds between cells, this process is more efficient than C photosynthesis. To build Kranz anatomy into rice leaves, plant biologists need a developmental map. They don't know what sets a plant cell on the path to becoming part of a vein, a mesophyll or bundle sheath cell, and they don't know how these cells form the spatial patterns typical of C plants. Langdale has been studying development in maize, because it's one of only a few plants with both C leaves (the blades around the corn cob) and C leaves (all the rest). By examining the differences in gene-expression patterns between these leaf types, Langdale has found about 280 genes that seem to be involved in the formation of this Kranz anatomy. After whittling down the list to 70, based on function, her group “took each gene and put it into rice with a promoter to switch it on all the time”, she explains. Not all of the genes seemed to have an effect. Langdale is now doing further studies of ten or so of the genes that seem the most promising. Genetic engineering has advanced substantially since the C Rice Project started. Researchers used to have to transform rice one gene at a time, now they can do two or three genes at once. Eventually, they expect to be able to build a C shuttle — a set of genes required for C photosynthesis that can be inserted into various plants in one go. But first they must work out what changes to make. Langdale estimates that, realistically, C rice won't make an appearance in farmers' fields until at least 2039. In the past, improving yields through photosynthetic interventions was not a practical research focus — these were “intellectual questions”, says Christine Raines, a plant scientist at the University of Essex in Colchester, UK. Now the idea is in vogue, and researchers have the funding to test their ideas. “We will begin to see a lot of papers coming out in the next 18 months,” she says. But significant challenges lie ahead. “Organisms resist attempts to reprogram them,” says Melis, and these projects seek to alter the very heart of a plant's chemistry. Before they can make such unprecedented changes, scientists will need, for example, to better understand how resources such as sugars and lipids are routed to certain places in plant cells. Although this will be difficult, many plant biologists think that engineering photosynthesis could be the best hope for feeding a growing population and combating food insecurity. “Photosynthesis is the last big unexplored route to improving yields,” says Harbinson.


News Article | May 3, 2017
Site: www.eurekalert.org

Chicken is a favorite, inexpensive meat across the globe. But the bird's popularity results in a lot of waste that can pollute soil and water. One strategy for dealing with poultry poop is to turn it into biofuel, and now scientists have developed a way to do this by mixing the waste with another environmental scourge, an invasive weed that is affecting agriculture in Africa. They report their approach in ACS' journal Energy & Fuels. Poultry sludge is sometimes turned into fertilizer, but recent trends in industrialized chicken farming have led to an increase in waste mismanagement and negative environmental impacts, according to the United Nations Food and Agriculture Organization. Droppings can contain nutrients, hormones, antibiotics and heavy metals and can wash into the soil and surface water. To deal with this problem, scientists have been working on ways to convert the waste into fuel. But alone, poultry droppings don't transform well into biogas, so it's mixed with plant materials such as switch grass. Samuel O. Dahunsi, Solomon U. Oranusi and colleagues wanted to see if they could combine the chicken waste with Tithonia diversifolia (Mexican sunflower), which was introduced to Africa as an ornamental plant decades ago and has become a major weed threatening agricultural production on the continent. The researchers developed a process to pre-treat chicken droppings, and then have anaerobic microbes digest the waste and Mexican sunflowers together. Eight kilograms of poultry waste and sunflowers produced more than 3 kg of biogas -- more than enough fuel to drive the reaction and have some leftover for other uses such as powering a generator. Also, the researchers say that the residual solids from the process could be applied as fertilizer or soil conditioner. The abstract that accompanies this study is available here. The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies. Its main offices are in Washington, D.C., and Columbus, Ohio. To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.


News Article | March 7, 2017
Site: www.techtimes.com

After two consecutive seasons of poor rainfall leading to drought, Somalia is on the brink of another famine as 110 people, mostly women and children, died in the past 48 hours due to starvation and drought-related diseases. The deaths came from the villages of southwestern Bay region, the ground-zero of this year's drought, while it was not yet established how many people had died in other parts of the country. Prime Minister Hassan Ali Khaire announced the impending crises as he spoke before the drought committee. Four days earlier, the drought was declared as a national disaster by President Mohamed Abdullahi Farmajo. The prime minister, in a statement released by his office, was warned by the committee "about the humanitarian crises ... that is threatening the lives of the people and their livestock." The severe drought that hit the country has put the lives of more than 6 million Somalis in danger as food and water become scarce with rivers drying up. The present drought will "cost lives, further destroy livelihoods, and could undermine the pursuit of key state-building and peace-building initiatives," Peter de Clercq, United Nations's coordinator for Somalia, said. The country has been rocked by internal conflict for decades and beset with lack of infrastructure problem. He sees the urgent need to "scale up the drought response immediately." Khaire also called on the "business people and everyone to contribute to the drought response efforts aimed at saving the lives of the millions of Somalis dying from hunger and lack of water." In September last year, according to the Food and Agriculture Organization, around 5 million Somalis were in need of assistance. The number went as high as 6.2 in this year's drought. During the famine between 2010 and 2012, the United Nations and the United States Agency for International Development said the death toll had reached up to 258,000. Somalia is placed along South Sudan, Nigeria, and Yemen by UNICEF where an estimated 1.4 million children are vulnerable from the impending famine to hit the region. The United Nations and several aid agencies have developed a five-level scale called the Integrated Food Security Phase Classification (IPC) as a guide to classify different phases on food security situations. In Phase 5 of the IPC, a famine or humanitarian catastrophe is declared if more than two people die every day, more than 30 percent acute malnutrition rates are recorded, all livestock have died, food consumption is less than 2,100 kilocalories, and less than 4 liters of water is available for each person. Based on these criteria, by the time the United Nations declares a famine, there is already a widespread loss of lives. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | March 13, 2017
Site: www.techtimes.com

Beyond tourism concern, the trouble in Australia's Great Barrier Reef could spell trouble for mankind. It may seem far removed but the slow death the giant coral structure is experiencing could also foreshadow the doom that awaits the human society. This is even more alarming as the Great Barrier Reef is reported to have suffered from massive coral bleaching — the second of such event in two years. The question is not much in knowing what will happen to it and all other coral ecosystems in the world if the destruction goes on unabated but rather in knowing what will happen to society if it ever dies. All is not lost, however. Scientists agree that the Great Barrier Reef is in trouble and may be dying but it is not dead yet. It is not yet time to write the obituary. "This is a fatalistic, doomsday approach to climate change that isn't going to engage anyone and misinforms the public," coral reef expert Kim Cobb from Georgia Tech said. Cobb is convinced that a portion of the giant barrier reef and coral reefs around the world will stay beyond 2050. "I'm pretty confident of that. I'm put off by pieces that say we are doomed," he declared. These coral reefs are alive and they have the capacity to adapt to the changing climate. Researchers have discovered that some of the corals change their algal partners as they grow older. In this way, they can acquire algae that are more tolerant to heat brought about by global warming. There is hope, Terry Hughes, director of ARC Centre of Excellence for Coral Reef Studies, said. To save the coral ecosystem from demise is important to human survival. The 2014 report of the Food and Agriculture Organization underscored the importance of reefs as it provides some 17 percent of the protein global requirement. In some areas like Sierra Leone and Maldives, the figure may climb to as high as 70 percent. In addition, one-fourth of the marine species depend on coral reefs. There are several ways scientists believe they could do to save it and save humanity, too. A study conducted by the Smithsonian Tropical Research Institute in Panama found out that combination of warming and sea acidification is lethal to the health of corals. Based on this finding, one proposed conservation strategy is to add bicarbonates or lime to the water in order to reduce ocean acidity. It needs an estimated 10 cubic kilometers of lime every year to achieve this. To address warming, some scientists propose the building of giant shades on reefs in shallow waters. Replanting of corals with varieties that are heat-tolerant is also offered as one of the solutions. Toward this end, scientists are considering the idea of gardening coral reefs. These proposed strategies are limited when applied on a global scale. In the end, the reduction of carbon dioxide emissions is important to save the dying Great Barrier Reef and the whole coral ecosystem worldwide. "By 2050, we may still have corals, and things we call 'reefs', but they will be massive limestone structures that were built in the past, with tiny patches of living coral struggling to survive on them," coral ecologist Peter Sale said. He is convinced that the world without coral reefs will still survive but it will be less livable than we have now. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | April 26, 2017
Site: www.eurekalert.org

URBANA, Ill. - Researchers at the University of Illinois are using pigs as a model to study the best way of evaluating protein quality in foods eaten by children, a method that was proposed by the Food and Agriculture Organization (FAO) of the United Nations in 2011. "Plant proteins are the primary sources of amino acids in many parts of the world, whereas animal proteins are the primary sources in other parts of the world. However, the composition and digestibility of these types of proteins differ," says Dr. Hans H. Stein, professor of animal sciences at U of I and principal investigator of this research. Researchers in Stein's lab conducted a study to calculate protein scores for eight sources of protein, derived from both plants and animals. Protein scores compare the amount of digestible amino acids in a food with a "reference protein," a theoretical protein which contains fully digestible amino acids in the proportions required for human nutrition at a particular stage of life. The score which has been used for more than 20 years is the protein digestibility-corrected amino acid score, or PDCAAS. PDCAAS is calculated using the total tract digestibility of crude protein. However, this method has certain shortcomings. "The total tract digestibility fails to take into account nitrogen excretion in the hindgut," Stein says. "The PDCAAS also assumes that all amino acids in a foodstuff have the same digestibility as crude protein, but in reality, amino acid digestibilities differ." These flaws led to the development of a new measure, called the digestible indispensable amino acid score (DIAAS). The DIAAS is calculated using ileal digestibility values, because all absorption of amino acids takes place in the small intestine. It also uses values calculated individually for each amino acid. Stein and his team determined standardized ileal digestibility of crude protein and amino acids in eight sources of animal and plant protein: whey protein isolate, whey protein concentrate, milk protein concentrate, skimmed milk powder, pea protein concentrate, soy protein isolate, soy flour, and whole-grain wheat. They derived DIAAS scores from those ileal digestibility values. They also calculated PDCAAS-like scores by applying the total tract digestibility of crude protein in the ingredients to all amino acids. All dairy proteins tested in the study met Food and Agriculture Organization (FAO) standards as "excellent/high"-quality sources of protein for people six months of age or older, with DIAAS values of 100 or greater. Soy protein isolate and soy flour qualified as "good" sources of protein, with a score between 75 and 100. With scores below 75, pea protein concentrate and wheat did not qualify to make recommendations regarding protein quality. "Compared with DIAAS, PDCAAS calculations tended to underestimate the protein value of high quality protein sources, and overestimate the value of lower quality sources," says Stein. "Thus, to better meet protein requirements of humans, especially for people consuming diets that are low or marginal in digestible amino acids, DIAAS values should be used to estimate protein quality of foods." Stein acknowledged certain limitations in the study. "The protein sources used in this experiment were fed raw, and foods processed as they typically are for human consumption might well have different protein values." However, he says, it represents a step forward in determining protein quality. Funding for the research was provided by National Dairy Council, the non-profit organization founded by America's dairy farmers and funded by the national dairy checkoff program. The organization had no input into the experimental design or analysis. "The results of this pilot study indicate that dairy proteins may be an even higher quality source of protein compared to vegetable-based protein sources than previously thought," said Dr. Greg Miller, chief science officer at NDC. "While using DIAAS is a newer concept and more research will be needed, one thing rings true -- milk proteins are high quality and milk as a beverage has protein plus eight other essential nutrients, which is especially important when it comes to kids, because they need quality nutrition to help support their growth and development." The paper, "Values for digestible indispensable amino acid scores (DIAAS) for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores (PDCAAS)" was published in the February 2017 issue of the British Journal of Nutrition. The co-authors were John Mathai and Yanhong Liu of the University of Illinois.


News Article | April 26, 2017
Site: www.nature.com

The world has more than 50,000 edible plants. But 90% of the world's energy demands are fulfilled by just 15 crops, according to estimates by the Food and Agriculture Organization (FAO) of the United Nations. About two-thirds of our calorie intake is provided by three: rice, maize (corn) and wheat. Dependency on a handful of crops is problematic. In cultivating countless generations of a few staples, we have inadvertently lost some of their most valuable properties. Modern crops are susceptible to changing climatic conditions, for example, and are heavily affected by pests, which can claim 30–40% of global production of staple crops such as maize, rice and potatoes1 and call for ever-stronger pesticides. The nutritional content of what we grow is also declining. “Breeding and intensified cultivation for high yield tend to reduce the concentration of nutrients,” says Donald Davis, now retired, but who in 2004 documented, with colleagues at the Bio-Communications Research Institute in Wichita, Kansas, the nutritional decline of dozens of fruits and vegetables over a 50-year period2. Modern staples may produce more grain or fruit than their ancestors, but the edible product is not able to absorb or synthesize a corresponding amount of nutrients, Davis explains. In broccoli, for instance, iron has fallen by 32% and zinc by 37% since 1950. “Bigger heads mean lower mineral concentrations,” says Davis. “I always buy the smallest heads I can find.” Demand for food is set to increase over the next few decades (see page S6). To address issues of nutritional quality, scientists are looking to nature for help. Millions of years of adaptation to varied and often extreme environments has created a rich genetic diversity of wild relatives of modern staples. These plants represent an immense library of valuable traits with the potential to improve the quality and resilience of modern crops. Across the globe, researchers are trying to endow domesticated crops with these traits through interbreeding. “Plant-breeding programmes benefit from such genetic diversity by creating new crop varieties that are nutritious, use natural resources more efficiently, and are able to respond to stringent environmental conditions and destructive pests and diseases,” says Nora Castañeda-Álvarez, a plant biologist at the Crop Trust, a non-profit organization in Bonn, Germany. But if the full potential of plant-breeding programmes is to be realized, scientists need to conserve the many wild varieties that are threatened with extinction, before these plants disappear and take their secrets with them. The humble tomato is a staple crop in a large part of the world. It is the third most cultivated vegetable crop, according to the FAO, after potatoes and cassava; in 2014, around 170-million tonnes were produced, belonging to about 7,500 varieties of the species Solanum lycopersicum. But there is room for improvement. Wild tomatoes grow in a wide range of habitats, in defiance of pests and soil quality, and researchers are exploring whether these traits could be transferred to commercial varieties to improve resilience. A commercial tomato that could naturally fight off pests would be a major asset. Peter Hanson and Mohamed Rakha, plant geneticists at the World Vegetable Centre in Tainan, Taiwan, are using the wild tomato species Solanum pimpinellifolium, Solanum galapagense and Solanum cheesmaniae, all of which are found on the Galapagos Islands, to create new tomato varieties that are resistant to multiple diseases and insect pests. These wild tomatoes can fight off insects thanks to small hair-like structures called glandular trichomes that cover the leaves and stems. “These trichomes produce acyl sugars and other compounds that repel or are toxic to a wide range of insects,” says Hanson. Endowing a commercial tomato with these insect-repelling hairs involves 'back-crossing' with one of the wild species. Hanson is using a tomato elite line (a stock of pure seeds with certain traits) called CLN3682C, which is already resistant to bacterial wilt, tomato yellow leaf curl virus, root-knot nematodes and fusarium wilt. The plants that result from a cross are screened to identify those that carry the wild trait of interest as well as those already held by the elite variety, explains Hanson. If the wild insect-resistance traits have been genetically sequenced, selection can be accelerated — rather than monitoring expression, researchers can simply look for the presence of the gene or allele, known as marker-assisted selection. The selected plants are then crossed with each other, and the subsequent generation crossed with the elite variety to increase the odds of a plant carrying every possible desirable trait. “Insect-resistant varieties must also produce high yields of high-quality fruit,” says Hanson. This whole process is repeated for each wild species, so it takes time. “Each cross and selection takes most of a year to complete,” says Hanson. He estimates it will take about five years before a commercial tomato variety bearing the wild traits of insect resistance is available. In 2016, Mark Tester, a plant biologist at King Abdullah University of Science and Technology in Thuwal, Saudi Arabia, and PhD student Yveline Pailles found that S. galapagense and S. cheesmaniae are also able to thrive in highly salty soils3. The aim now is to breed this trait into commercial lines. “Tomatoes are the world's biggest horticultural crop, by far, and they use a lot of water,” says Tester. Commercial tomatoes need fresh water — an increasingly limited resource. “A major water source that is currently unused is brackish water,” he says. “This is the driver of my research.” He estimates that new lines of salt-tolerant tomatoes could reach breeders in a couple of years. Researchers are also improving the nutritional properties of tomatoes. In 2003, Hanson and colleagues released two tomato varieties in Taiwan that were bred to pack up to six times more vitamin A than the average tomato. The source of this, as well as their characteristic orange colour, is a gene called Beta, discovered in the wild tomato Solanum habrochaites in 1950, Hanson explains. “We hope our high-beta carotene cherry tomato varieties can become popular in home gardens in countries like Bangladesh where vitamin A deficiency is a problem, especially among children,” Hanson says. But demand in the first ten years has been poor. Hanson attributes this to difficulties in convincing people that orange-fleshed tomatoes are as good and tasty as the familiar red varieties. “The key factor is creating consumer demand,” he says, but a lack of resources has hampered the promotion of his tomatoes. At Oregon State University in Corvallis, vegetable breeder and geneticist Jim Myers is also creating more-nutritious tomatoes. He has bred purple tomatoes that are rich in antioxidants called anthocyanins. Tomato breeders have been trying to generate an anthocyanin-rich variety from various wild species, including Solanum lycopersicoides, Solanum peruvianum, Solanum chilense and S. cheesmaniae, for half a century, with little success. The one variety produced from these efforts, the Purple Smudge, was created in the 1950s and only weakly expresses anthocyanin-producing genes. Myers and his team crossed S. chilense and S. cheesmaniae. “If we combine the genes from the two wild species, then we obtain a dramatic increase in pigment expression — tomatoes as black as an eggplant,” Myers says. The result is the Indigo Rose, which contains between 10 and 30 milligrams of anthocyanin per 100 g of fresh fruit; the average tomato contains none. There are more than 20 Indigo Rose cultivars commercially available in the United States, most of which have been bred from the original lines that Myers created. Breeding wild traits into commercial crops is a lengthy process. To speed things up, neglected crops can be used in their entirety (see 'Investment in indigenous crops') or commercial plants can be genetically modified (GM). Indigo Rose tomatoes are not classed as GM — Myers used only conventional breeding techniques. Genetic modification techniques allow researchers to insert genes of wild varieties directly into plants, greatly increasing the speed at which new cultivars can be created. Genes can also be sourced from different organisms, such as bacteria. “At that point, the possibilities of introducing new characteristics into our crops will be, in principle, unlimited,” says Francesca Quattrocchio, a plant geneticist at the University of Amsterdam. But although GM crops are accepted in Australia, the United States and most of South America, there is significant opposition elsewhere. GM crops are either banned or have to go through an intensive authorization process in many European and African countries. Any time saved in the creation of a new variety through genetic modification is lost by hold ups further down the line, and restrictions on who can use it. The valuable genetic diversity held in wild-crop relatives could be at risk, however. More than 70% of wild relatives have been identified as being in urgent need of conservation4. As a whole, around 20% of the world's plants are threatened with extinction5. The expansion of agriculture into natural ecosystems is one of the leading causes of this decline, Castañeda-Álvarez says. And plant species in the tropics are twice as likely to be threatened as those in temperate regions5. “These plants and animal breeds have developed and survived because they were best adapted to a given territory,” says Edie Mukiibi, vice president of Slow Food International, an organization in Bra, Italy, that works to prevent the disappearance of local food cultures. “We must take care of this biodiversity because it represents the best of several millennia of agriculture.” The International Potato Center in Lima is seeking to protect potato varieties in situ through their Chirapaq Ñan network. The idea, says Severin Pohlreich, a plant geneticist at the centre, is to record locations across Peru, Bolivia and Chile with a rich diversity of potato varieties. “This network will help enable and support in situ conservation monitoring of the world's largest potato gene pool, right at its centre of diversity,” he says. Other projects focus on conserving wild varieties outside their natural habitats. Around the world, about 1,750 gene banks, as well as botanical gardens, hold more than 7.4 million seeds or plant tissues from thousands of crop species. Nearly 90% of these samples are held in national gene banks — the Centre for Genetic Resources (CGN), part of Wageningen University in the Netherlands, for instance, currently holds one of world's largest and most diverse collection of lettuces. To protect against the loss of seeds in collections such as these, the Svalbard Global Seed Vault acts as a backup. Located deep in a mountain on the Norwegian archipelago of Svalbard, the bank has capacity for 2.5 billion seeds; currently, it holds more than 880,000 samples, representing the world's major food crops. The seeds are meant to be used only in an emergency — be it a major catastrophe or incremental loss of diversity over time. “Each gene bank prepares a duplicate of their collection and sends this to Svalbard,” explains Castañeda-Álvarez. “External users, like you and me, can't make seed requests directly to Svalbard — this can only be made through the corresponding gene bank in case of emergency,” she says. The only withdrawal so far was made by the International Centre for Agricultural Research in the Dry Areas (ICARDA) in 2015, to re-establish its collection after it relocated its gene bank to Lebanon and Morocco from Aleppo, Syria. In February, ICARDA returned more than 15,000 seeds to Svalbard. The Crop Trust, which is responsible for the vault, sees the preservation of crop diversity as a crucial means of attaining global food security. The trust also heads a US$50-million research initiative on crop wild relatives, in collaboration with the UK's Royal Botanic Gardens, Kew, and a number of breeders and researchers around the world. The ten-year initiative launched in 2011 and is funded by the Norwegian government. The aim of the project is to collect and preserve more than 450 wild relatives of 29 priority crops, says Hannes Dempewolf, Head of Global Initiatives at the Crop Trust. In the long term, the plan is to breed a new generation of superior crops that carry one or more of the desirable traits of their wild relatives. Pre-breeding programmes — in which genetic traits are isolated and introduced into breeding lines that are easier to cross with commercial varieties than wild plants — have been established for 19 wild relatives, including aubergines and rice. Wild-crop relatives look set to be a part of the answer to the food-insecurity problem, whether they are used to form new crops or growers simply make better use of the neglected crops already available to them. “The genetic diversity available in wild varieties is, at the moment, the best solution,” says Quattrocchio, at least until GM crops gain wider acceptance. Castañeda-Álvarez agrees, “Crop wild relatives can help us to continue producing more sustainable food, in the amount and quality the world needs.” But first, she says, “we need to conserve them to secure their availability”.


News Article | April 18, 2017
Site: www.eurekalert.org

Banning transshipment at-sea -- the transfer of fish and supplies from one vessel to another in open waters--is necessary to diminish illegal fishing, a team of researchers has concluded after an analysis of existing maritime regulations. "This practice often occurs on the high seas and beyond the reach of any nation's jurisdiction, allowing ships fishing illegally to evade most monitoring and enforcement measures, offload their cargo, and resume fishing without returning to port," explains Jennifer Jacquet, an assistant professor in New York University's Department of Environmental Studies and one of the paper's co-authors. "It's one way that illegal fish are laundered into the seafood market." "More significantly, transshipment at-sea can facilitate trafficking and exploitation of workers who are trapped and abused on fishing vessels because there is simply no authority present to protect those being exploited," adds Chris Ewell, an NYU undergraduate at the time of the study and the paper's lead author. The paper, which appears in the journal Marine Policy, may be downloaded here: http://bit. . In their study, the researchers focused on the regulation of transshipment, which the United Nations Food and Agriculture Organization (FAO) defines as the "act of transferring the catch from one fishing vessel to either another fishing vessel or to a vessel used solely for the carriage of cargo." Specifically, they examined transshipment at-sea regulations across 17 Regional Fisheries Management Organizations (RFMOs)--multi-national entities responsible for regulating fisheries on the high seas--to create a "scorecard" on the permissibility of this practice around the globe. The researchers note that transshipment at-sea regulations have become increasingly strict in most RFMOs since the late 1990s. However, in 2015, the year of study, only five RFMOs had mandated even a partial ban and only one RFMO, the South East Atlantic Fisheries Organization (SEAFO), has mandated a total ban on transshipment at-sea. "A total ban on transshipment at-sea on the high seas would support the ability of oversight and enforcement agencies to detect and prevent illegal fishing and also likely reduce human trafficking and forced labor on the high seas," the study's authors recommend. The study's other authors included Mikaela Ediger, a fellow at NYU School of Law's Institute for International Justice and Law, Dana Miller, currently a marine scientist at Oceana and a postdoctoral researcher at the University of British Columbia at the time of the study, and John Hocevar, oceans campaign director at Greenpeace USA. The research was supported, in part, by the Alfred P. Sloan Foundation and the Pew Charitable Trusts, as well as by an undergraduate research grant from NYU.


"This practice often occurs on the high seas and beyond the reach of any nation's jurisdiction, allowing ships fishing illegally to evade most monitoring and enforcement measures, offload their cargo, and resume fishing without returning to port," explains Jennifer Jacquet, an assistant professor in New York University's Department of Environmental Studies and one of the paper's co-authors. "It's one way that illegal fish are laundered into the seafood market." "More significantly, transshipment at-sea can facilitate trafficking and exploitation of workers who are trapped and abused on fishing vessels because there is simply no authority present to protect those being exploited," adds Chris Ewell, an NYU undergraduate at the time of the study and the paper's lead author. The paper, which appears in the journal Marine Policy. In their study, the researchers focused on the regulation of transshipment, which the United Nations Food and Agriculture Organization (FAO) defines as the "act of transferring the catch from one fishing vessel to either another fishing vessel or to a vessel used solely for the carriage of cargo." Specifically, they examined transshipment at-sea regulations across 17 Regional Fisheries Management Organizations (RFMOs)—multi-national entities responsible for regulating fisheries on the high seas—to create a "scorecard" on the permissibility of this practice around the globe. The researchers note that transshipment at-sea regulations have become increasingly strict in most RFMOs since the late 1990s. However, in 2015, the year of study, only five RFMOs had mandated even a partial ban and only one RFMO, the South East Atlantic Fisheries Organization (SEAFO), has mandated a total ban on transshipment at-sea. "A total ban on transshipment at-sea on the high seas would support the ability of oversight and enforcement agencies to detect and prevent illegal fishing and also likely reduce human trafficking and forced labor on the high seas," the study's authors recommend. Explore further: Hidden no more: First-ever global view of transshipment in commercial fishing industry More information: Christopher Ewell et al, Potential ecological and social benefits of a moratorium on transshipment on the high seas, Marine Policy (2017). DOI: 10.1016/j.marpol.2017.04.004


News Article | May 3, 2017
Site: phys.org

Chicken is a favorite, inexpensive meat across the globe. But the bird's popularity results in a lot of waste that can pollute soil and water. One strategy for dealing with poultry poop is to turn it into biofuel, and now scientists have developed a way to do this by mixing the waste with another environmental scourge, an invasive weed that is affecting agriculture in Africa. They report their approach in ACS' journal Energy & Fuels. Poultry sludge is sometimes turned into fertilizer, but recent trends in industrialized chicken farming have led to an increase in waste mismanagement and negative environmental impacts, according to the United Nations Food and Agriculture Organization. Droppings can contain nutrients, hormones, antibiotics and heavy metals and can wash into the soil and surface water. To deal with this problem, scientists have been working on ways to convert the waste into fuel. But alone, poultry droppings don't transform well into biogas, so it's mixed with plant materials such as switch grass. Samuel O. Dahunsi, Solomon U. Oranusi and colleagues wanted to see if they could combine the chicken waste with Tithonia diversifolia (Mexican sunflower), which was introduced to Africa as an ornamental plant decades ago and has become a major weed threatening agricultural production on the continent. The researchers developed a process to pre-treat chicken droppings, and then have anaerobic microbes digest the waste and Mexican sunflowers together. Eight kilograms of poultry waste and sunflowers produced more than 3 kg of biogas—more than enough fuel to drive the reaction and have some leftover for other uses such as powering a generator. Also, the researchers say that the residual solids from the process could be applied as fertilizer or soil conditioner. Explore further: Maximizing profits using poultry litter as fertilizer More information: Samuel O. Dahunsi et al. Bioconversion of(Mexican Sunflower) and Poultry Droppings for Energy Generation: Optimization, Mass and Energy Balances, and Economic Benefits, Energy & Fuels (2017). DOI: 10.1021/acs.energyfuels.7b00148 Abstract Anaerobic co-digestion of pretreated and untreated samples of Tithonia diversifolia with poultry droppings was carried out to establish a permanent solution to the menace of this stubborn weed present in crops worldwide. The physicochemical and microbial characteristics of the substrates (T. diversifolia, poultry droppings, and rumen contents) were evaluated using standard methods. The initial high chemical oxygen demand (COD) values were significantly reduced by 60.45 and 56.33% after digestion. In all the experiments, biogas production was progressive until between the 16th and 21st days in most cases, after which a decrease was observed until the end of the experiments. The most desirable actual/experimental biogas yields from both experiments were 2984.20 and 1408.02 m3/kg total solids (TS) fed, with desirability of 100% for both experiments. Gas chromatographic analysis revealed the CH4 and CO2 contents of both experiments to be 67 ± 1.5%; 22 ± 2% and 60 ± 1%; 23 ± 2%, respectively. The response surface methodology (RSM) model and the artificial neural networks (ANNs) model were employed in data optimization, and the optimal values for each of the five major parameters optimized are as follows: temperature (A) = 37.20 °C, pH (B) = 7.50, retention time (C) = 27.95 days, total solids (D) = 11.97 g/kg, and volatile solids (E) = 8.50 g/kg. The root-mean-square error of biogas for RSM (105.61) was much higher than that for ANNs (84.65). In the pretreated experiment, the most desirable predicted yield for RSM model was 3111.07 m3/kg TS fed, while that of ANNs model was 3058.50 m3/kg TS fed; for the experiment without pretreatment, it was 1417.39 and 1412.50 m3/kg TS fed, respectively. In all, there was a 54.44% increase in predicted biogas yield in the experiment with pretreatment over the untreated. Based on the coefficient of determination (R2), the mean error, and predicted biogas yields, the ANNs model was found to be more accurate than RSM in the study. The energy balance revealed a positive net energy which adequately compensated for the thermal and electrical energies used in carrying out thermo-alkaline pretreatment. The co-digestion of these substrates for bioenergy generation is hereby advocated.

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