Daily Archives: July 28, 2017

Roses are red, but science could someday turn them blue. Thats one of the possible future applications of a technique researchers have used to genetically engineer blue chrysanthemums for the first time.

Chyrsanthemums come in an array of colours, including pink, yellow and red. But all it took to engineer the truly blue hueand not a violet or bluish colourwas tinkering with two genes, scientists report in a study published on July 26 inScience Advances. The team says that the approach could be applied to other commercially important flowers, including carnations and lilies.

Consumers love novelty, says Nick Albert, a plant biologist at the New Zealand Institute for Plant & Food Research in Palmerston North, New Zealand. And people actively seek out plants with blue flowers to fill their gardens.

Plenty of flowers are bluish, but its rare to find true blue in nature, says Naonobu Noda, a plant researcher at the National Agriculture and Food Research Organization near Tsukuba, Japan, and lead study author. Scientists, including Noda, have tried to artificially produce blue blooms for years:efforts that have often produced violet or bluish huesin flowers such as roses and carnations. Part of the problem is that naturally blue blossoming plants arent closely related enough to commercially important flowers for traditional methodsincluding selective breedingto work.

Most truly blue blossoms overexpress genes that trigger the production of pigments called delphinidin-based anthocyanins. The trick to getting blue flowers in species that arent naturally that colour is inserting the right combination of genes into their genomes. Noda came close in a 2013 studywhen he and his colleagues found that adding a gene from a naturally blue Canterbury bells flower (Campanula medium) into the DNA of chrysanthemums (Chrysanthemum morifolium) produced a violet-hued bloom.

Noda says he and his team expected that they would need to manipulate many more genes to get the blue chrysanthemum they produced in their latest study. But to their surprise, adding only one more borrowed gene from the naturally blue butterfly pea plant (Clitoria ternatea) was enough.

Anthocyanins can turn petals red, violet or blue, depending on the pigments structure. Noda and his colleagues found that genes from the Canterbury bells and butterfly pea altered the molecular structure of the anthocyanin in the chrysanthemum. When the modified pigments interacted with compounds called flavone glucosides, the resulting chrysanthemum flowers were blue. The team tested the wavelengths given off by their blossoms in several ways to ensure that the flowers were truly blue.

The quest for blue blooms wouldn't only be applicable to the commercial flower market. Studying how these pigments work could also lead to the sustainable manufacture of artificial pigments, says Silvia Vignolini, a physicist at the University of Cambridge, UK, who has studied themolecular structure of the intensely blue marble berry.

Regardless, producing truly blue flowers is a great achievement and demonstrates that the underlying chemistry required to achieve 'blue' is complex and remains to be fully understood, says Albert.

This article is reproduced with permission and wasfirst publishedon July 26, 2017.

Excerpt from:
True Blue Chrysanthemum Flowers Produced with Genetic Engineering - Scientific American

Papaya trees bask in the evening light on a Hawaiian farm. Enabling crops to resist diseases through genetic modification was a key reason for the survival of Hawaii's papaya industry. Image: Eugene Kim, CC BY 2.0

Which is more disruptive to a plant: genetic engineering (GE) or conventional breeding?

It often surprises people to learn that GEcommonly causes less disruption to plantsthan conventional techniques of breeding. But equally profound is the realisation that the latest GE techniques, coupled with a rapidly expanding ability to analyse massive amounts of genetic material, allow us to make super-modest changes in crop plant genes that will enable farmers to produce more food with fewer adverse environmental impacts. Such super-modest changes are possible with CRISPR-based genome editing, a powerful set of new genetic tools that isleading a revolution in biology.

My interest in GE crops stems from my desire to provide more effective and sustainable plant disease control for farmers worldwide. Diseases often destroy 10 to 15 per cent of potential crop production, resulting inglobal losses of billions of dollars annually.

The risk of disease-related losses provides an incentive to farmers to use disease-control products such as pesticides. One of my strongest areas of expertise is in the use of pesticides for disease control. Pesticides certainly can be useful in farming systems worldwide, but they have significant downsides from a sustainability perspective. Used improperly, they can contaminate foods. They can pose a risk to farm workers. And they must be manufactured, shipped and applied all processes with a measurable environmental footprint. Therefore, I am always seeking to reduce pesticide use by offering farmers more sustainable approaches to disease management.

What follows are examples of how minimal GE changes can be applied to make farming more environmentally friendly by protecting crops from disease. They represent just a small sampling of thebroad landscape of opportunitiesfor enhancing food security and agricultural sustainability that innovations in molecular biology offer today.

Genetically altering crops the way these examples demonstrate creates no cause for concern for plants or people. Mutations occur naturally every time a plant makes a seed; in fact, they are the very foundation of evolution. All of the food we eat has all kinds of mutations, and eating plants with mutations does not cause mutations in us.

A striking example of how a tiny genetic change can make a big difference to plant health is the strategy of knocking out a plant gene that microorganisms can benefit from. Invading microorganisms sometimes hijack certain plant molecules to help themselves infect the plant. A gene that produces such a plant molecule is known as asusceptibility gene.

We can useCRISPR-based genome editingtocreate a targeted mutationin a susceptibility gene. A change of as little as a single nucleotide in the plants genetic material the smallest genetic change possible canconfer disease resistancein a way that is absolutely indistinguishable from natural mutations that can happen spontaneously. Yet if the target gene and mutation site are carefully selected, a one-nucleotide mutation may be enough to achieve an important outcome.

There is a substantial body of research showing proof-of-concept that a knockout of a susceptibility gene can increase resistance in plants to a very wide variety of disease-causing microorganisms. An example that caught my attention pertained topowdery mildew of wheat, because fungicides (pesticides that control fungi) are commonly used against this disease. While this particular genetic knockout is not yet commercialised, I personally would rather eat wheat products from varieties that control disease through genetics than from crops treated with fungicides.

The power of viral snippets

Plant viruses are often difficult to control in susceptible crop varieties. Conventional breeding can help make plants resistant to viruses, but sometimes it is not successful.

Early approaches to engineering virus resistance in plants involved inserting a gene from the virus into the plants genetic material. For example, plant-infecting viruses are surrounded by a protective layer of protein, called the coat protein. The gene for the coat protein of a virus calledpapaya ring spot viruswas inserted into papaya. Through a process called RNAi, this empowers the plant to inactivate the virus when it invades. GE papaya has been a spectacular success, in large partsaving the Hawaiian papaya industry.

Through time, researchers discovered thateven just a very small fragmentfrom one viral gene can stimulate RNAi-based resistance if precisely placed within a specific location in the plants DNA. Even better, they found we canstack resistance genesengineered with extremely modest changes in order to create a plant highly resistant to multiple viruses. This is important because, in the field, crops are often exposed to infection by several viruses.

Does eating this tiny bit of a viral gene sequence concern me? Absolutely not, for many reasons, including:

Tweaking sentry molecules

Microorganisms can often overcome plants biochemical defenses by producing molecules calledeffectorsthat interfere with those defenses. Plants respond by evolving proteins to recognise and disable these effector molecules. These recognition proteins are called R proteins (R standing for resistance). Their job is to recognise the invading effector molecule and trigger additional defenses.

A third interesting approach, then, to help plants resist an invading microorganism is to engineer an R protein so that it recognises effector molecules other than the one it evolved to detect. We can then use CRISPR to supply a plant with the very small amount of DNA needed to empower it to make this protein.

The latest GE techniques, coupled with a rapidly expanding ability to analyse massive amounts of genetic material, allow us to make super-modest changes in crop plant genes that will enable farmers to produce more food with fewer adverse environmental impacts.

This approach, like susceptibility knockouts, is quite feasible, based onpublished research. Commercial implementation will require some willing private- or public-sector entity to do the development work and to face the very substantial and costly challenges of the regulatory process.

The three examples here show that extremely modest engineered changes in plant genetics can result in very important benefits. All three examples involve engineered changes that trigger the natural defenses of the plant. No novel defense mechanisms were introduced in these research projects, a fact that may appeal to some consumers. The wise use of the advanced GE methods illustrated here, as well as others described elsewhere, has the potential to increase the sustainability of our food production systems, particularly given thewell-established safetyof GE crops and their productsfor consumption.

Paul Vincelli is Provosts Distinguished Service Professor at the University of Kentucky. This article is republished from Ensia.

More here:
When genetic engineering is the environmentally friendly choice - eco-business.com

Illustration by Luisa Rivere/Yale E360

The worldwide effort to return islands to their original wildlife, by eradicating rats, pigs, and other invasive species, has been one of the great environmental success stories of our time.Rewilding has succeeded on hundreds of islands, with beleaguered species surging back from imminent extinction, and dwindling bird colonies suddenly blossoming across old nesting grounds.

But these restoration campaigns are often massively expensive and emotionally fraught, with conservationists fearful of accidentally poisoning native wildlife, and animal rights activists having at times fiercely opposed the whole idea. So what if it were possible to rid islands of invasive species without killing a single animal? And at a fraction of the cost of current methods?

Thats the tantalising but also worrisome promise of synthetic biology, aBrave New Worldsort of technology that applies engineering principles to species and to biological systems. Its genetic engineering, but made easier and more precise by the new gene editing technology called CRISPR, which ecologists could use to splice in a DNA sequence designed to handicap an invasive species, or to help a native species adapt to a changing climate. Gene drive, another new tool, could then spread an introduced trait through a population far more rapidly than conventional Mendelian genetics would predict.

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Synthetic biology, also called synbio, is already a multi-billion dollar market, for manufacturing processes in pharmaceuticals, chemicals, biofuels, and agriculture. But many conservationists consider the prospect of using synbio methods as a tool for protecting the natural world deeply alarming. Jane Goodall, David Suzuki, and others havesigned a letterwarning that use of gene drives gives technicians the ability to intervene in evolution, to engineer the fate of an entire species, to dramatically modify ecosystems, and to unleash large-scale environmental changes, in ways never thought possible before.The signers of the letter argue that such a powerful and potentially dangerous technology should not be promoted as a conservation tool.

Environmentalists and synthetic biology engineers need to overcome what now amounts to mutual ignorance, a conservationist says.

On the other hand, a team of conservationbiologists writing early this yearin the journalTrends in Ecology and Evolutionran off a list of promising applications for synbio in the natural world, in addition to island rewilding:

Transplanting genes for resistance to white nose syndrome into bats, and for chytrid fungus into frogs and other amphibians.

Giving corals that are vulnerable to bleaching carefully selected genes from nearby corals that are more tolerant of heat and acidity.

Using artificial microbiomes to restore soils damaged by mining or pollution.

Eliminating populations of feral cats and dogs without euthanasia or surgical neutering, by producing generations that are genetically programmed to be sterile, or skewed to be overwhelmingly male.

And eradicating mosquitoes without pesticides, particularly in Hawaii, where they are highly destructive newcomers.

Kent Redford, a conservation consultant and co-author of that article, argues that conservationists and synbio engineers alike need to overcome what now amounts to mutual ignorance. Conservationists tend to have limited and often outdated knowledge of genetics and molecular biology, he says.Ina 2014 articleinOryx, he quoted one conservationist flatly declaring, Those were the courses we flunked. Stanford Universitys Drew Endy, one of the founders of synbio, volunteers in turn that 18 months ago he had never heard of the IUCN the International Union for Conservation of Nature or its Red List of endangered species.In engineering school, the ignorance gap is terrific, he adds.But its symmetric ignorance.

At a major synbio conference he organised last month in Singapore, Endy invited Redford and eight other conservationists to lead a session on biodiversity, with the aim, he says, of getting engineers building the bioeconomy to think about the natural world ahead of time My hope is that people are no longer merely nave in terms of their industrial disposition.

Likewise, Redford and the co-authors of the article inTrends in Ecology and Evolution, assert that it would be a disservice to the goal of protecting biodiversity if conservationists do not participate in applying the best science and thinkers to these issues. They argue that it is necessary to adapt the culture of conservation biologists to a rapidly-changing reality including the effects of climate change and emerging diseases.Twenty-first century conservation philosophy, the co-authors conclude, should embrace concepts of synthetic biology, and both seek and guide appropriate synthetic solutions to aid biodiversity.

Through gene drive technology, mice, rats or other invasive species can theoretically be eliminated from an island without killing anything.

The debate over synthetic biodiversity conservation, as theTrends in Ecology and Evolutionauthors term it, had its origins in a2003 paperby Austin Burt, an evolutionary geneticist at Imperial College London.He proposed a dramatically new tool for genetic engineering, based on certain naturally occurring selfish genetic elements, which manage to propagate themselves in as much as 99 percent of the next generation, rather than the usual 50 percent. Burt thought that it might be possible to use these super-Mendelian genes as a Trojan horse, to rapidly distribute altered DNA, and thus to genetically engineer natural populations. It was impractical at the time.Butdevelopmentof CRISPR technology soon brought the idea close to reality, and researchers have since demonstrated the effectiveness of gene drive, as the technique became known, in laboratory experiments on malaria mosquitoes, fruit flies, yeast, and human embryos.

Burt proposed one particularly ominous-sounding application for this new technology: It might be possible under certain conditions, he thought, that a genetic load sufficient to eradicate a population can be imposed in fewer than 20 generations. And this is, in fact, likely to be the first practical application of synthetic biodiversity conservation in the field. Eradicating invasive populationsis of coursethe inevitable first step in island rewilding projects.

The proposed eradication technique is to use the gene drive to deliver DNA that determines the gender of offspring.Because the gene drive propagates itself so thoroughly through subsequent generations, it can quickly cause a population to become almost all male and soon collapse.The result, at least in theory, is the elimination of mice, rats, or other invasive species from an island without anyone having killed anything.

Research to test the practicality of the method including moral, ethical, and legal considerations is already under way through a research consortium ofnonprofitgroups, universities, and government agencies in Australia, New Zealand, and the United States.At North Carolina State University, for instance, researchers have begun working with a laboratory population of invasive mice taken from a coastal island.They need to determine how well a wild population will accept mice that have been altered in the laboratory.

The success of this idea depends heavily,according togene drive researcher Megan Serr, on the genetically modified male mice being studs with the island lady mice Will she want a hybrid male that is part wild, part lab? Beyond that, the research programme needs to figure out how many modified mice to introduce to eradicate an invasive population in a habitat of a particular size. Other significant practical challenges will also undoubtedly arise.For instance,a study early this yearin the journalGeneticsconcluded that resistance to CRISPR-modified gene drives should evolve almost inevitably in most natural populations.

Political and environmental resistance is also likely to develop.In an email, MIT evolutionary biologist Kevin Esvelt asserted that CRISPR-based gene drives are not suited for conservation due to the very high risk of spreading beyond the target species orenvironment. Even a gene drive systemintroduced toquickly eradicate an introduced population from an island, he added, still is likely to have over a year to escape or be deliberately transported off-island. If it is capable of spreading elsewhere, that is a major problem.

Even a highly contained field trial on a remote island is probably a decade or so away, said Heath Packard, of Island Conservation, a nonprofit that has been involved in numerous island rewilding projects and is now part of the research consortium.We are committed to a precautionary step-wise approach, with plenty of off-ramps, if it turns out to be too risky or not ethical.But his group notes that 80% of known extinctions over the past 500 or so years have occurred on islands, whicharealso home to 40% of species now considered at risk of extinction. That makes it important at least to begin to study the potential of synthetic biodiversity conservation.

Even if conservationists ultimately balk at these new technologies, business interests are already bringing synbio into the field for commercial purposes.For instance, a Pennsylvania State University researcher recently figured out how to use CRISPR gene editing to turn off genes that cause supermarket mushrooms to turn brown.The USDepartment of Agriculturelast year ruledthat these mushrooms would not be subject to regulation as a genetically modified organism because they contain no genes introduced from other species.

With those kinds of changes taking place all around them, conservationists absolutely must engage with the synthetic biology community, says Redford, and if we dont do so it will be at our peril. Synbio, he says, presents conservationists with a huge range of questions that no one is paying attention to yet.

This article originally appeared on Yale Environment 360 and is republished here with permission.

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Should genetic engineering be used as a tool for conservation? - chinadialogue

Plant species blooming blue flowers are relatively rare, Naonobu Noda, a plant biologist at the National Agriculture and Food Research Organization in Japan who led the research, noted in an email.

It took Dr. Noda and his colleagues years to create their blue chrysanthemum. They got close in 2013, engineering a bluer-colored one by splicing in a gene from Canterbury bells, which naturally make blue flowers. The resulting blooms were violet. This time, they added a gene from another naturally blue flower called the butterfly pea.

Both of these plants produce pigments for orange, red and purple called delphinidin-based anthocyanins. (Theyre present in cranberries, grapes and pomegranates, too.) Under a few different conditions, these pigments, which are sensitive to changes in pH, can start a chemical transformation within a flower, rendering it blue.

The additional gene did the trick. It added a sugar molecule to the pigment, shifting the plants pH and altering the chrysanthemums color. The researchers confirmed the color as blue by testing its wavelengths in the lab.

What they did was already being done in nature: No blue flowers actually have blue pigment. Neither do blue eyes or blue birds. They all get help from a few clever design hacks.

Blue flowers tend to result from the modification of red pigments shifting their acidity levels, switching up their molecules and ions, or mixing them with other molecules and ions.

Some petunias, for example, have a genetic mutation that breaks pumps inside their cells, altering their pH and turning them blue. Some morning glories shift from blue upon opening to pink upon closing, as acidity levels in the plant fluctuate. Many hydrangeas turn blue if the soil is acidified, as many gardeners know.

In vertebrates, blue coloring often is more about structure. Blue eyes exist because, lacking pigments to absorb color, they reflect blue light. Blue feathers, like those of the kingfisher, would be brown or gray without a special structural coating that reflects blue.

Reflection is also the reason for the most intense color in the world, the shiny blue of the marble-esque Pollia fruit in Africa.

Despite widespread blue-philia, the new chrysanthemums may meet a cool reception. A permit is required to sell genetically modified organisms in the United States, and there isnt one for these transgenic flowers.

Officials are wary of transgenic plants that might take root in the environment, because of their possible impacts on other plants and insects. Dr. Noda and his colleagues are working on blue chrysanthemums that cant reproduce, but its unlikely youll see them in the flower shop anytime soon.

Read the rest here:
Scientists Give a Chrysanthemum the Blues - New York Times