Soil Study

Battling the blight Bean blight's reach expands to both tropical and temperate regions of the world. Shree Singh, a professor at the University of Idaho, has spent his career researching ways to generate cultivars of common bean resistant to diseases. According to Singh, "Common blight is by far the most severe and widely occurring bacterial disease that adversely affects common bean production worldwide." Common blight is caused by two species of bacteria belonging to the Xanthomonas genus. It is a difficult disease to attack. The bacteria can move along with seeds and plant matter. "When contaminated seeds are planted, the bacteria can then go on to infect the germinating plant and spread further," says Singh. Infected plant matter left behind after harvest can also infect the next cycle of crops. Complicating matters further, different strains of the bacteria can exist on the same seed. In fact, "A single field in Wisconsin yielded more than...

Dramatically Dynamic Genomic Evolution of a Mighty Mite As a major natural enemy of several damaging agricultural pests, the predatory mite Metaseiulus occidentalis is used in many agricultural settings as an effective biological control agent. Some of its favorite prey include spider mites that feed on and destroy various fruits including strawberries, apples, peaches and grapes. "I have been studying the behavior, ecology, and molecular biology of these mites for more than 40 years," said Prof. Marjorie Hoy lead author from the University of Florida USA, "so I was very keen to sequence the entire genome to reveal the full catalogue of genes." To explore the unique biology of this agriculturally important predator the researchers focused their studies on genes putatively involved in processes linked to paralysis and pre-oral digestion of prey species and its rather rare par haploid sex determination system, as well as how it senses chemical cues from its surro...

Modern Corn Hybrids More Resilient to Nitrogen Stress In an analysis of 86 field experiments, agronomists found that corn hybrids released after 1990 prove more resilient than their predecessors in multiple ways. Modern hybrids maintain per-plant yield in environments with low nitrogen, can bounce back from mid-season stress and have an improved ability to take up nitrogen after silking, even if they suffered from nitrogen deficiency during flowering. The study suggests reserving a portion of nitrogen fertilizer to apply later in the season could be a good bet for growers, said Tony Vyn, professor of agronomy. "This is like insurance," he said. "Previously, withholding some of your nitrogen for later could be perceived as a risky venture -- you don't want to inadvertently cause nitrogen deficiency. But this paper suggests that with modern hybrids, that risk is lower." Nitrogen is an essential building block of plant proteins and plays a vital role...

The Fight Against Citrus Greening Disease A new study of the citrus greening bacterium's effects on its insect vector, the Asian citrus psyllid, reveals multiple changes within the insect. During the infection, the pathogen affects the 'good' bacteria living inside the insect and alters the psyllid's metabolism in ways that could help spread the pathogen further. Ultimately, the study may reveal weak points in the transmission cycle that could yield novel and highly specific targets for control strategies. These approaches could be more effective and environmentally friendly than large-scale pesticide use. The study appears in the journal PLOS ONE. "Our work in this area could not be timelier," said Michelle Cilia, an assistant professor at BTI and research molecular biologist in the U.S. Department of Agriculture's Agricultural Research Service. "Last week, the USDA's National Agricultural Statistics Service lowered its already dire pr...

Genome-Edited Plants, Without DNA What makes this work so groundbreaking is that these genetic modifications look just like genetic variations resulting from the selective breeding that farmers have been doing for millennia. IBS Director of the Center for Genome Engineering Jin-Soo Kim explains that "the targeted sites contained germ line-transmissible small insertions or deletions that are indistinguishable from naturally occurring genetic variation." CRISPR is an acronym for Clustered Regularly Interspaced Short Palindromic Repeat, which refers to the unique repeated DNA sequences found in bacteria and archaea. CRISPR is now used widely for genome editing. What's crucial in genetic engineering is for the gene editing tool to be accurate and precise, which is where CRISPR-Cas9 excels. CRISPR-Cas9 uses a single guide RNA (sgRNA) to identify and edit the target gene and Cas9 (a protein) then cleaves the gene, resulting in site-specific DNA double-strand breaks (...

Increasing Production of Seed Oils Many plants store oil and protein in their seeds as energy sources needed for germination. The National Institute for Basic Biology's Drs. Masatake Kanai, Shoji Mano and Mikio Nishimura et al., in the process of studying the mechanism that controls the synthesis and degradation of oils in plant seeds, revealed that oils are actively synthesized only during the mid-phase of the seed formation process. The research group considered that by extending the period seeds synthesize oils, they should be able to increase their oil content in seeds. Therefore, using the model plant Arabidopsis, they extended the expression time of WRI1, a gene that activates oil synthesis. As a result, they were able to increase the oil content of the seeds to 140% as compared to wild-type. Also, while extending the oil synthesis phase, suppressing protein synthesis in the late-phase of seed formation increased the oil content of the seeds as compared to wild-typ...

Genetic Transfer to Prevent Self-Pollination Self-pollination or 'selfing' can be bad for a plant resulting in inbreeding and less healthy offspring. This breakthrough could be used to breed stronger more resilient crops faster and at lower cost; a new approach in the quest for a secure and plentiful food supply. The team took the self-fertile plant thale cress -- Arabidopsis thaliana -- a relative of cabbages, cauliflowers and oilseed rape, and made it self-incompatible by the transfer of just two genes from poppies that enable the recipient plant to recognize and reject its own pollen whilst permitting cross-pollination. Such conversion of a selfing plant to a self-incompatible one has been a long term goal of self-incompatibility research. The basic anatomy of most flowers means the male pollen is produced next to the female reproductive organs running the real risk of self-pollination, rather than receiving pollen from a different flower transported by the wind...

More Efficient Water Management in Rice Crops The aim of the study was to quantify the water used in two different systems of rice crop, water-seeded system and dry-seeded system, during the first month of crop growth. This research was carried out in California (USA) along with the Universidad Politécnica de Madrid (UPM) and 15 researchers from other universities and research centers of Italy, China, Egypt and United States. Results suggest that these two systems of water management show no differences regarding the total crop cycle. Rice is the third-largest global crop area (165m hectares) after wheat and corn, but it is the most important crop worldwide considering the large area and the amount of people who depend on their harvest. Globally, the cultivated area in China and India represents half of the total surface. Spain has the second largest rice area of the European Union with 115,000 hectares behind Italy. Rice crops usually grow under conditions of continuously...

Sensor Could Detect Viruses, Kill Cancer Cells This system can be customized to detect any DNA sequence in a mammalian cell and then trigger a desired response, including killing cancer cells or cells infected with a virus, the researchers say. "There is a range of applications for which this could be important," says James Collins, the Termeer Professor of Medical Engineering and Science in MIT's Department of Biological Engineering and Institute of Medical Engineering and Science (IMES). "This allows you to readily design constructs that enable a programmed cell to both detect DNA and act on that detection, with a report system and/or a respond system." Collins is the senior author of a Sept. 21 Nature Methods paper describing the technology, which is based on a type of DNA-binding proteins known as zinc fingers. These proteins can be designed to recognize any DNA sequence. "The technologies are out there to engineer proteins to bind to vir...

Blocking Differentiation is Enough to Give Cells 'Stemness' Efforts in the past to create stem cells have typically involved finding ways to take target cells and "dedifferentiate" them into multipotent cells, but this is typically a painstaking process. According to Tomokatsu Ikawa, the first and corresponding author of the paper published in Stem Cell Reports, "We decided to look at the possibility that somatic stem cells could be maintained in a stem cell-like state where they could proliferate without undergoing differentiation." To test this, the team took mouse hematopoietic progenitor cells--cells that give rise to white blood cells--and modified them to overexpress a protein called Id3. Id3 inhibits the expression of E-proteins, which are involved in differentiation in somatic cells. They then placed the cells into culture conditions containing certain cytokines, and instead of differentiating into B-cells, the cells continued to divide as ste...

In 2030, We Will have Local Protein on Our Plate The bulk of the protein on our plates originates in Brazil, because the protein fodder consumed by food-producing animals consists mostly of soy grown there. If the vision proposed by the ScenoProt project, coordinated by the Natural Resources Institute Finland (Luke), becomes reality, by 2030 our food production will no longer be dependent on a handful of large Brazilian companies. "This project seeks to increase Finland's self-sufficiency in protein production from the current less-than-twenty to sixty per cent. A similar change must take place in the whole of Europe, as soy cultivation destroys rain forest in Brazil, accelerating the climate change," says Principal Research Scientist Anne Pihlanto of Luke. New foodstuffs pave the way to a healthier diet Efforts are taken to increase self-sufficiency in protein protection by developing foodstuffs in which protein originates in new sources, such as insects a...

Lack of Sleep May Zap Cell Growth, brain activity, Study in Plants Suggests Albrecht von Arnim, a molecular biologist based in the Department of Biochemistry and Cellular and Molecular Biology, studied plants but said the concepts may well translate to humans. His team examined how protein synthesis--the process that determines how organisms grow and how cells renew themselves--changes over the course of the daily day-night cycle. He also explored whether any such changes are controlled by the organism's internal time keeper, the circadian clock. Proteins are newly created in every cell by translating messages made from the cell's own DNA, the genome. Von Arnim's findings, published in the journal Plant Cell, show not only that protein synthesis activity changed over the course of the day, but also that it was under the influence of the circadian clock. "When we misalign our behavior with our circadian clock, for example by creating jet lag, or by work...

Microbiomes Could Hold Keys to Improving Life Microbial life forms including viruses, bacteria and fungi are the most diverse and abundant organisms on earth. They have shaped our evolutionary origins for billions of years and continue to have widespread impact on the planet, its environment and the species inhabiting it. Together, they make up microbiomes that influence each other, the environment, and the host organisms that these microbial communities thrive in. The UMIC foresees that the microbiomes populating our planet and its many diverse species and environments could be leveraged through genetic engineering for applications that improve the greater good, and that many milestones could be reached on this front within ten years. "Microbes are everywhere. Therefore understanding microbiomes, whether they be the ones that live in and on our bodies or the ones in the environment, is essential to understanding life," said Silver, who in addition to being one...

Secrets of a Rice-Killing Fungal Toxin Mycotoxins are toxic compounds produced by fungi that are not directly involved in growth, development, or reproduction. These secondary metabolites typically colonize crops and are a real economic burden for farmers. TeA is known to be produced by at least three different plant pathogenic fungi, and is associated with spoiling of fruits, vegetables, and food-crops, as well as post-harvest decay. "Now that we know the gene responsible for biosynthesis of this harmful toxin," notes co-lead author Takayuki Motoyama, "after further testing we might be able to devise a way to regulate its expression and prevent destruction of important crops." When studying microorganisms like fungus, researchers have found that genes for many secondary metabolites are silent under laboratory conditions, which has made finding them especially difficult. The CSRS group led by Hiroyuki Osada has extensive experience studying secondary m...

A cure for Vitamin B6 Deficiency In many tropical countries, particularly in sub-Saharan Africa, cassava is one of the most important staple foods. People eat the starchy storage roots but also the leaves as a vegetable. Both have to be cooked first to remove the toxic cyanide compounds that cassava produces. But the roots have a disadvantage: although rich in calories, in general they contain only few vitamins. Vitamin B6 in particular is present in only small amounts, and a person for whom cassava is a staple food would have to eat about 1.3 kg of it every day for a sufficient amount of this vital vitamin. Serious deficiency in Africa Vitamin B6 deficiency is prevalent in several African regions where cassava is often the only staple food people's diet. Diseases of the cardiovascular and nervous systems as well as are associated with vitamin B6 deficiency. Plant scientists at ETH Zurich and the University of Geneva have therefore set out to find a way to increase ...

Cellular Stress Management in People and Plants Proteins have many tasks to fulfil in the structure, function and regulation of cells. Once the proteins are formed, they are further adapted for their very specific jobs. "One of the most frequent changes is the attachment of an acetic acid residue on the amino-terminal end of the proteins. Lacking this modification, the plants cannot survive, and this same lack in certain proteins in humans leads to illness, developmental problems and cell death," explains Prof. Hell. Although up to 80 percent of proteins in the cytoplasm of human cells are modified by an acetic acid residue at their amino terminus, the function of this modification has only been studied for a handful of proteins. The Heidelberg researchers generated genetically modified plants with protein populations that carry less acetic acid residues and analyzed the results. "The changed pattern of amino-terminal modification proteins by acetic acid surpr...

Beneficial Natural Compounds in Tomato Scientists at the John Innes Centre have found a way to produce industrial quantities of useful natural compounds efficiently, by growing them in tomatoes. The compounds are phenylpropanoids like Resveratrol, the compound found in wine which has been reported to extend lifespan in animal studies, and Genistein, the compound found in soybean which has been suggested to play a role in prevention of steroid-hormone related cancers, particularly breast cancer. As a result of the research led by Dr Yang Zhang and Dr Eugenio Butelli working in Professor Cathie Martin's lab at the John Innes Centre, one tomato can produce the same quantity of Resveratrol as exists in 50 bottles of red wine. One tomato has also produced the amount of Genistein found in 2.5kg of tofu. Dr Zhang and Butelli have been studying the effect of a protein called AtMYB12 which is found in Arabidopsis thaliana, a plant found in most UK gardens and used as a mode...

Wild Plants Call to Carnivores to Get Rid of Pests While this strategy may work in someone's backyard, it's not an option on a large farm. In an October 4 Trends in Plant Science Opinion paper, agricultural researchers in Sweden and Mexico argue that one way around the scalability problem is to bring back the odors and nectars found in wild plants that attract pest-eating predators. This could be done either through breeding programs or by using artificial devices. "Wild plants commonly emit natural odors when they are damaged that attract natural enemies of pest insects--even as humans we smell it when our neighbour is mowing the lawn -- odors can carry very precise information," says co-author Martin Heil of CINVESTAV-Irapuato in Mexico. "Agriculture has bred such defenses out of crops, and since these odors have no negative effects on human consumers, we want to replace what the plant would already be doing." It's also not unusual for w...