Wheat genes could help fight fungal epidemics: Nature Newsas farmers around the world anxiously monitor the march of a deadly orange fungus across their wheat fields,
the cloning of two fungus-fighting genes. Both genes fend of a wide range of'rust'fungi, including several types of stripe rust (Puccinia striiformis) and leaf rust (P. triticina.
The genes are found in some wild wheat, and can be bred into commercial varieties but that can be an arduous process taking several years to complete.
Knowing what the genes are and precisely where they are located in the genome could speed things up significantly,
breeders say. The results are welcome news as plant pathologists race to arm themselves against an ongoing epidemic of stem rust (P. graminis) caused by a recently emerged fungus called Ug99 (see'Wheat fungus spreads out of Africa'.
'The epidemic was isolated first in Uganda and has since spread eastwards into Iran. From there, pathologists believe wind currents may sweep Ug99 spores into India and, eventually, China.
says Jorge Dubcovsky, a plant geneticist at the University of California, Davis, who led one of the studies.
One problem is that breeders have relied traditionally on disease-resistance genes that are very effective
Increasingly, breeders are turning to a class of defence gene with a broader spectrum of resistance.
One such gene, called Lr34, has been fending off leaf and stripe rusts in some agricultural wheat for the past century.
and we haven't seen any sign of selection for virulence against that gene. Lr34 has also become a key component of wheat-breeding programmes aimed at distributing new varieties to the developing world.
But despite its venerable history, researchers have been unable to isolate the gene or work out how it confers resistance to fungal diseases.
The gene encodes a protein that is similar to molecular transporters that have been implicated in drug resistance.
Dubcovsky discovered the second fungi-fighting gene several years ago as a result of work on a wild wheat that has yields with an unusually high protein content2.
The gene that led to higher protein content happened to be located near a gene, called Yr36,
In wheat carrying just the Yr36 gene, 90%of the leaf was covered in rust. But in plants with both genes, only 5%of the leaf bore the fungus.
Dubcovsky has bred already lines that carry both genes and has begun to distribute them to farmers.
A similar synergistic effect between genes may also be useful in the fight against Ug99,
says Lagudah. Although Lr34 alone does not render plants resistant to the fungus, researchers have found that the gene can enhance the resistance found in some varieties4.
Lagudah says that breeders are pursuing this finding in hopes of generating Ug99-resistant varieties of wheat.
and public reluctance about transgenic crops is likely to keep transgenic approaches off the table for some time.
Missouri, announced that it was halting development of transgenic herbicide-resistant strains of wheat after US farmers expressed concerns that they would not be able to export the crops to other countries.
The transgenic option is open, says Keller, but I don't think we're going to see that application very soon.
European disarray on transgenic crops: Nature Newseurope has failed to reach a decision on whether France and Greece should be ordered to lift their national bans on cultivation of a genetically modified maize (corn) known as MON801,
which is responsible for scientific risk assessments on GM CROPS in Europe, has reported that there is no case against MON801,
and that the national bans are effectively denying countries that use biotechnology in agriculture the access to the European market they are allowed under trade rules.
and many of its governments, have long been hostile to agricultural biotechnology. A number of member states did not implement the EU's decision to approve MON801 in 1998,
allows the EU to approve GM CROPS when there is no scientific evidence of danger to health or environment;
Natalie Moll of Europabio, the biotech industry lobby group in Brussels, says that the regulatory committee's failure to bring an end to cultivation bans gives the usual European mixed signal that we have the toughest scientific approval system in the world,
In the meantime, the EFSA is working through its backlog of applications for the cultivation of 13 other GM CROPS.
At the same time the state government of Bavaria stopped all field experiments on GM CROPS, confining them to greenhouses,
and the Bavarian environment minister Markus Soder announced his intention to block cultivation of GM CROPS in the state.
Meanwhile, public opposition to GM CROPS may be slipping. In a Eurobarometer public-opinion survey published last year, the percentage of those who said they were against GM CROPS fell from 70%to 58%.
Nitrogen fertilizer warning for China: Nature Newsresearchers warn that the overuse of nitrogen fertilizer in China is poisoning air,
) The hybrid embryos also failed to properly express genes thought to be critical for pluripotency the ability to develop into a wide variety of cell types.
and increased their expression of many genes, including several known to be involved in pluripotency. Hybrid embryos
and to express known pluripotency genes properly. Lanza says that his team has ploughed through many different protocols and thousands of embryos over the years,
says reproductive biologist Justin St john of the University of Warwick in Coventry, UK, who is developing mouse-pig hybrid embryos.
Furthermore, the nuclear genome may have difficulty communicating with energy-producing structures called mitochondria which are inherited directly from the mother,
they might be able to circumvent those roadblocks by altering the expression of specific genes,
says cell biologist Jose Cibelli of Michigan State university in East Lansing. Meanwhile, there may be other ways to reprogram a cell with a different species'DNA
notes embryologist Anthony Perry at the RIKEN Center for Developmental Biology in Kobe, Japan. Is there really only one path that will give you a pup?
Nature Newsone of the most famous experiments in biology isn't the solid piece of work it's usually portrayed as,
which they convert, through photosynthesis, into biomass. But plant growth benefits from elevated CO2 levels only up to a point,
an evolutionary biologist at the Spanish National Research Council's Do  ana Biological Station in Seville.
Plants genes get fine tailoring: Nature Newsafter decades of searching, plant biologists have found a way to selectively snip out one gene
and replace it with another. The method promises to be a boon to both basic research
which bind to specific sites in a genome and then cut nearby strands of DNA.
the gap can be sealed either simply in effect deleting the targeted gene or filled in with a new gene.
Zinc-finger nucleases have recently been used to create human immune cells that are resistant to HIV (see'Designer protein tackles HIV'.
says David Ow, a plant biologist at the US Department of agriculture Plant Gene expression Center in Albany, California.
Plant biologists have long been frustrated by the lack of a simple method for either deleting a specific gene from the genome or replacing it with another gene.
the fast-growing weed with a small genome favoured by many plant biologists as a model system,
has not been targeted amenable to gene replacement. To have a really good model system you need targeted gene replacement,
says Joseph Ecker, a plant biologist at the Salk Institute for Biological Studies in La jolla, California.
We've been kind of limping along without it. Sporadic reports of plant gene-replacement strategies have come and gone,
but none has been versatile or efficient enough for wide-scale use. In 1997, a Nature paper reporting targeted gene disruption in Arabidopsis raised the hopes of many plant researchers3.
When that paper came out we all thought'This is it, 'says Ow. Unfortunately it didn't pan out.
complex genomes, chock full of large families of genes with very similar DNA sequences, says Vipula Shukla, a scientific group leader at Dow Agrosciences in Indianapolis, Indiana.
That makes targeting a specific gene more difficult. The challenges associated with any kind of sequence-specific modification in plants are profound,
For one of the new studies, Shukla and her colleagues at Dow Agrosciences teamed up with Sangamo Biosciences
The team has used zinc fingers to replace a gene called IPK1 with an herbicide-resistance gene.
Meanwhile, the other study1 is the work of a research team led by Daniel Voytas, a plant biologist at the University of Minnesota in Minneapolis and a member of the Zinc Finger Consortium,
'Voytas's group has engineered herbicide-resistant tobacco by inserting specific mutations into a gene called Sur.
Both groups have replaced their selected genes at a frequency much higher than anyone has achieved before,
For instance, designing zinc fingers that target only one gene will probably still be a challenge,
a plant biologist at Karlsruhe University in Germany who is developing zinc-finger nucleases for use in Arabidopsis.
Shukla notes that her team was able to target IPK1 without affecting a 98%-identical gene called IPK2.
Voytas'team was also able to target their gene without hitting another gene that is 96%identical.
But Voytas adds that some of the zinc-finger nucleases the team studied did cleave both genes,
and costs could be higher for other labs. The technique could also assuage a common concern about transgenic crops.
when we create transgenic plants, we insert the transgene somewhere in the genome, and we don't know exactly where it happens to insert,
says Wilhelm Gruissem, a plant biologist at The swiss Federal Institute of technology in Zurich. Now you can target the transgene to a specific location.
Timeline: Swine flu: Nature Newsa new strain of swine flu-influenza A (H1n1)- is spreading around the globe.
This timeline will be updated continually with key dates, drawing on authoritative information from the World health organization (WHO), the US Centers for Disease Control and Prevention (CDC) and other sources.
At this time, there is no evidence to indicate the development of widespread antiviral resistance among pandemic H1n1 viruses.
A report in Eurosurveillance estimates a reproduction number for the virus the average number of secondary cases generated by a single primary case of 2. 3 in Japan.
Medimmune, a biotechnology firm in Gaithersburg, Maryland, wins a $90 million contract from the federal government to begin developing a live attenuated vaccine for H1n1.
This virus may have given us a grace period, but we do not know how long this grace period will last,
A modeling study in Science suggests that the virus spreads at a rate comparable to that of previous influenza pandemics.
The latest 0505/en/index. html>WHO figures say the virus has now spread to 21 countries.
The pigs likely caught the virus from a Canadian who had visited recently Mexico, making this the first known case of human-to-animal transmission.
The agency also announces it will refer to the virus not as swine flu but as influenza A (H1n1.
codifying evidence that biofuels are significantly dirtier than they were thought once to be. The California Air Resources Board approved its'low-carbon fuel standard'on 23 april,
Despite intense opposition from the US corn (maize) ethanol industry, the rule takes into account agricultural expansion abroad caused by rising grain prices as food crops are diverted for biofuels.
The US Environmental protection agency is reviewing its own ruling that will establish greenhouse-gas criteria under the national biofuels mandate.
still performs better than any other biofuel. The California regulation does not yet include specific numbers for biodiesel,
although the indirect impact could be even higher because of massive emissions from expanding palm-oil plantations, particularly in Indonesia.
Nature Newsa white-faced, red-coated Hereford cow named Dominette has become the first cow to have sequenced its genome.
Information from the 5-year, US$53-million cow-genome project is being used to trace the genetic legacy of bovine domestication after centuries of careful breeding.
genes for better milk. The project is having a profound impact on the industry today,
says Curt Van tassel, a geneticist at the United states Department of agriculture in Beltsville, Maryland, and a member of the consortium that did the work.
says Patrick Cunningham, an animal geneticist at Trinity college Dublin in Ireland and chief scientific adviser to The irish government.
But the bovine genome is large at 3 billion bases, it is roughly the same size as the human genome making it difficult to study.
In the absence of genomic information, breeding programmes have relied on tracking the physical characteristics of the animals,
rather than harnessing genetic markers in the DNA sequence. We have very little knowledge of the genes that are involved in cattle breeding
says James Womack, a genome researcher at Texas A&m University in College Station, and another member of the consortium.
This opens the door to finding the genes that underlie important traits. Dominette's genome sequence, published today in Science1,
has revealed also a few genetic underpinnings of the bovine lifestyle. For example, Dominette has many copies of some of the genes involved in the innate immune system,
which could reflect the heavy load of microbes she carries in her four-chambered stomach.
Those bacteria are needed to break down grass and other delicacies in her fibrous diet but could also pose an infection risk.
Researchers have used also the genome sequence to assemble a collection of more than 37,000 locations in the genome that contain frequent single-base changes in DNA sequence2.
These genetic markers were used then to characterize the genetic diversity found in nearly 500 cattle from 19 breeds.
The results were surprising: although diversity has decreased greatly over time as would be expected for an animal that has been domesticated
and much more diverse than dogs, says Kim Worley, a genome researcher at the Baylor College of Medicine in Houston, Texas,
But Harris Lewin, a genome biologist at the University of Illinois at Urbana-Champaign who also assisted with the analysis of the genome
wild cows that lived in Europe until their extinction in the seventeenth century providing periodic infusions of new genes,
Genetic markers will help breeders to improve the health of their herds as well as the quality
Improved genetic techniques could push up agricultural yields by as much as 50%or 12 gallons of milk per cow each year,
estimates Van tassel. The new sequence also shows that the human genome is more similar to the genome of cattle than to mice suggesting that, for some diseases,
Geneticist Michel Georges of the University of Li  ge in Belgium worries that the focus on improving agricultural herds could cause researchers to stop investigating the biology underlying those improvements.
Nature Newssufficient efforts are not being made to protect 10%of the world's forests by 2010 as agreed under the Convention on Biological Diversity (CBD) according to a new analysis1.
%because it was thought this level of protection was necessary for biodiversity conservation. He says that it is recognized now that protecting forests is also important for efforts to stabilize climate change
so if we are failing to meet the target it could be even worse for climate stabilization than for biodiversity.
The authors also include the 34'biodiversity hotspots'identified by Conservation International (CI), a non-governmental organization based in Arlington, Virginia.
on average, 10.2%of the forests in areas designated as biodiversity hotspots by the CI were protected.
Burgess says it is good news that many of the most important areas for biodiversity are being protected at a level above the 10%target.
Bioelectricity better than biofuels for transport: Nature Newsvehicles propelled by biomass-fired electricity would travel farther on a given crop
and produce fewer greenhouse-gas emissions than vehicles powered by ethanol, researchers report today. Burning biomass to produce electricity is generally more efficient than converting it into ethanol.
And electric vehicles although often more expensive to make and maintain than many vehicles with internal combustion engines are also more efficient at converting that energy into motion.
comparing cumulative greenhouse-gas emissions for both biofuels and bioelectricity. They found that the bioelectric route came out ahead of both corn ethanol
suggests that, on average, an electric vehicle powered by biomass will travel 81%farther than an internal-combustion vehicle powered by cellulosic ethanol
the reductions in greenhouse-gas emissions using bioelectricity are more than double those calculated for the cellulosic ethanol.
and emissions per hectare that allows for a direct comparison between bioelectricity and liquid biofuels.
By contrast, US fuel policy is focused on biofuels. The federal mandate ramps up from 9 billion gallons of biofuels in 2008 (compared with almost 138 billion gallons of gasoline) to 36 billion gallons of biofuels by 2022.
On 5 may, the US Environmental protection agency proposed greenhouse-gas standards for various biofuels, but made no provision for electric transport.
However, there are proposals to deploy something like California's low carbon fuel standard at the national level.
what kind of role advanced biofuels might have in the future. He says the key is to have a flexible policy that sets a goal
For these countries, there is a much smaller potential pool of foreign genetic resources in which to seek crops with heat-tolerant traits,
which maize varieties were conserved in gene banks. In particular, they looked to see if the varieties that currently grow under higher temperatures those that will be most important for farmers as the climate warms are preserved well.
They found that countries with some of these important varieties have the poorest conservation of plant genetic resources
The gene-bank collections from many areas that are likely to have the widest range of diversity are either incomplete
His colleagues add that These countries are particularly high priorities for urgent collection and conservation of maize genetic resources.
and conserving and exchanging genetic material, will be vital to take advantage of the existing capacity to deal with climate change.
Emile Frison, director-general of Bioversity International, a not-for-profit research organization in Rome, says the study clearly demonstrates the interdependence of countries regarding plant genetic resources.
Nature Newspublic-health experts are warning that a lack of surveillance may be allowing the 2009 pandemic H1n1 flu virus to go undetected in pigs.
This raises the risk that the virus could circulate freely between humans and pigs, making it more likely to reassort into a deadlier strain,
Their main concern tends to be that any reports of the pandemic virus in pigs might provoke overreactions such as the mass culling of pigs that took place in Egypt
So far the role of animals has not been demonstrated in the virus's epidemiology or spread,
2009), Gavin Smith, a flu geneticist at the University of Hong kong, and his colleagues concluded that the lack of systematic swine surveillance allowed for the undetected persistence and evolution of this potentially pandemic strain for many years.
The virus originated from a mixture of swine flu strains, and pigs are an obvious part of the epidemiology of the new virus,
says Smith. Yet the number of swine-flu sequences in the international Genbank database is about a tenth of that for avian flu viruses.
Circulation of the virus between pigs and humans is definitely a possibility he adds. The pandemic virus has so far been found in pigs from just one farm, in Alberta, Canada,
where it spread throughout the herd. But noone has been able to pin down how the herd became infected.
Scientists at the Veterinary Laboratories Agency in Weybridge, UK, have shown that pigs can easily become infected with the virus,
and readily transmit it between themselves and shed it into the environment. Past pandemic viruses have gone also on to become endemic in pig populations.
It's absolutely surprising that a virus this contagious in both humans and swine and which has been reported in humans in 76 countries,
has only been reported in one swine farm in Canada, says Jimmy Smith, head of livestock affairs at the World bank in WASHINGTON DC,
Absence of evidence of the pandemic virus in pig populations is not evidence of absence,
The avian H5n1 flu virus leads to serious disease in poultry and causes huge economic losses,
flu viruses, although common, tend to cause only mild disease, so there is no obligation to report cases of swine flu,
much less take samples for genetic and antigenic analysis. The OIE has asked, however its member states to voluntarily report any occurrences of the 2009 pandemic virus in pigs.
Surveillance for swine flu is not something that has been high on the agenda of government services,
Although the network has detected not yet the new virus in pigs, its coordinator Kristien Van Reeth,
an animal virologist at Ghent University in Belgium, admits that participating labs have taken just a few hundred to a thousand samples each over the past year.
-and public-health communities underestimated the potential for pigs to generate a pandemic virus . Although pigs can be infected with many subtypes of flu,
The emergence of the reassorted H1n1 pandemic virus which current research indicates noone has any immunity to, apart, perhaps,
H2 and H3 bird viruses, meaning that they would have no immunity. This shows that the world needs a comprehensive surveillance system of all influenza subtypes
Sexual gene shuffling suppressed in plants: Nature Newsusing a combination of three genetic mutations, plant researchers have disrupted the usual process of genetic shuffling during the formation of reproductive cells male pollen and female ova.
These triple mutant plants instead produce pollen and ova genetically identical to the cells of the parent plant by simple mitotic cell division.
The results, published today in PLOS Biology could bring plant breeders a step closer to generating crops that produce their seeds completely asexually a process called apomixis1.
the intricate genetic networks that brought about this'hybrid vigor'are shuffled, generating offspring that are often not as vigorous as their parent.
Instead, researchers believe that a combination of genes or particular mutations will be needed to engineer an apomictic crop plant.
the need to engineer plants that generate their reproductive cells by mitosis rather than by meiosis, the form of cell division that shuffles the genome and passes different selections of genes into each reproductive cell.
says plant geneticist Peter Van dijk of Keygene, a plant breeding company based in Wageningen, The netherlands.
Mercier and his colleagues searched for genes in the model plant Arabidopsis thaliana that were likely to be associated with meiosis on the basis of where
and when the genes were expressed. They found one that they named omission of second division (OSD1)
because plants mutant for this gene lacked the second round of cell division that occurs during meiosis. When the researchers combined mutations in the OSD1 gene with mutations in two other genes that affect meiosis,
these cells are diploid (containing two copies of the genome), like the body cells of the plant, rather than haploid (containing one copy of the genome) like normal reproductive cells.
The triple mutants are reminiscent of a mutant reported last year by Imran Siddiqi and his colleagues at the Centre for Cellular and Molecular biology in Hyderabad
India2. That mutant, called dyad, also produced female reproductive cells by mitosis rather than meiosis, but only at low frequency,
says Ueli Grossniklaus, a plant developmental biologist at the University of Zurich, but one practical limitation is the reliance upon mutations in three different genes.
If we want to apply this, eventually we'll have to combine these three traits with other desirable traits,
And the more genes you have to bring together, the harder it will be. Achieving apomixis is still a distant goal, however.
fertilization causes the chromosome number of the offspring to double in each generation, an undesirable outcome.
Boost for conservation of plant gene assets: Nature Newsan international treaty aimed at protecting and improving access to the world's plant genetic resources is set to dole out its first round of research grants this week amid cash-flow problems that could endanger future awards.
The grants, which will support research into new crop varieties and plant-conservation efforts in developing countries,
mark the fifth anniversary of the adoption of the International Treaty on Plant Genetic Resources for Food and Agriculture by the Food and Agricultural organization of the United nations. The treaty is known best for its role in paving the way for construction of the Svalbard Global
and those that have ratified it are legally bound to pass on genetic information about the world's 64 most important food crops,
This information might be held in gene banks or in the form of crops growing in a farmer's field, for example.
such as new crop varieties, which are developed using genetic material obtained through the treaty. Anyone who uses the treaty's genetic material in a patented,
commercialized product must agree to give back into a common pot 1. 1%of the sales they make on the product.
Nations that are party to the treaty have made 1. 1 million genetic samples available through it
and around 200,000 exchanges of genetic material take place every year showing it has so far been a success,
says Bert Visser, director of the Centre for Genetic Resources in Wageningen, The netherlands. The treaty has enabled the creation of a global gene pool,
he says. David Ellis, curator of the Plant Genetic Resources Preservation Program within the US Department of agriculture's research service, says it has become standard practice for genetic material to be accessed
and exchanged through the treaty. He adds that it has also been useful in clarifying the terms and conditions under
and use genetic resources from around the world, Visser says. Everyone needs something from everyone else,
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