Tag Archives: genetic diversity

Preserving Seeds that Feed the World: the Svalbard Global Seed Vault

Six hundred miles from the North Pole, on an island the size of West Virginia, at the end of a tunnel bored into a mountain, lies a vault filled with more than 1 million samples of seeds harvested from 6,374 species of plants grown in 249 locations around the globe.The collection, the largest of its kind, is intended to safeguard the genetic diversity of the crops that feed the world.  If disaster wipes out a plant, seeds from the vault could be used to restore the species. If pests, disease or climate change imperil a food source, a resistant trait found among the collection could thwart the threat.

While some countries have their own seed banks—Colorado State University houses one for the U.S.—the Svalbard Global Seed Vault serves as a backup. The vault, built in 2008 at a cost of about $9 million, is owned and maintained by Norway, but its contents belong to the countries and places that provide the samples.  “It works like a safe-deposit box at the bank,” said Cary Fowler, an American agriculturalist who helped found the vault. “Norway owns the facility, but not the boxes of the seeds.”

In 2015, after the International Center for Agricultural Research in the Dry Areas was destroyed in the Syrian civil war, scientists who had fled the country withdrew seeds to regenerate the plants in Lebanon and Morocco.  “It had one of the world’s biggest and best collections of wheat, barley, lentils, chickpeas, faba beans and grass pea,” Dr. Fowler said. “It was the chief supplier of a disease-resistant wheat variety for the Middle East.”  In 2017, the group returned copies of its seeds to the vault.

The 18,540-square-foot seed vault includes three rooms with the capacity to house 4.5 million samples of 500 seeds each—a maximum of 2.25 billion seeds. The environment’s natural temperature remains below freezing year round, but the seeds are stored at a chillier -18 degrees Celsius, or around -0.4 degrees Fahrenheit. They’re expected to last for decades, centuries or perhaps even millennia….

While dwindling diversity might not seem like an imminent threat, four chemical companies now control more than 60% of global proprietary seed sales…That concentration of power, some worry, could lead to less agricultural variety and more genetic uniformity…In the meantime, the seed vault (which doesn’t store genetically modified seeds) will continue to accept deposits in an effort to preserve all of the options it can.

Excerpts from Craven McGinty, Plan to Save World’s Crops Lives in Norwegian Bunker, WSJ,  May 29, 2020

Genetically Modified Crops May Become the Norm: the case of Golden Rice

Golden Rice is a genetically modified (GM) crop that could help prevent childhood blindness and deaths in the developing world. Ever since Golden Rice first made headlines nearly 20 years ago, it has been a flashpoint in debates over GM crops. Advocates touted it as an example of their potential benefit to humanity, while opponents of transgenic crops criticized it as a risky and unnecessary approach to improve health in the developing world.

Now, Bangladesh appears about to become the first country to approve Golden Rice for planting..Golden Rice was developed in the late 1990s by German plant scientists Ingo Potrykus and Peter Beyer to combat vitamin A deficiency, the leading cause of childhood blindness. Low levels of vitamin A also contribute to deaths from infectious diseases such as measles. Spinach, sweet potato, and other vegetables supply ample amounts of the vitamin, but in some countries, particularly those where rice is a major part of the diet, vitamin A deficiency is still widespread; in Bangladesh it affects about 21% of children.

To create Golden Rice, Potrykus and Beyer collaborated with agrochemical giant Syngenta to equip the plant with beta-carotene genes from maize. They donated their transgenic plants to public-sector agricultural institutes, paving the way for other researchers to breed the Golden Rice genes into varieties that suit local tastes and growing conditions.

The Golden Rice under review in Bangladesh was created at the International Rice Research Institute (IRRI) in Los Baños, Philippines. Researchers bred the beta-carotene genes into a rice variety named dhan 29…Farmers in Bangladesh quickly adopted an eggplant variety engineered to kill certain insect pests after its 2014 introduction, but that crop offered an immediate benefit: Farmers need fewer insecticides. Golden Rice’s health benefits will emerge more slowly,

Excerpts from Erik Stokstad,  After 20 Years, Golden Rice Nears Approval, Science,  Nov. 22, 2019

Unsafe Genes: DARPA

DARPA created the Safe Genes program to gain a fundamental understanding of how gene editing technologies function; devise means to safely, responsibly, and predictably harness them for beneficial ends; and address potential health and security concerns related to their accidental or intentional misuse. Today, DARPA announced awards to seven teams that will pursue that mission, led by: The Broad Institute of MIT and Harvard; Harvard Medical School; Massachusetts General Hospital; Massachusetts Institute of Technology; North Carolina State University; University of California, Berkeley; and University of California, Riverside. DARPA plans to invest $65 million in Safe Genes over the next four years as these teams work to collect empirical data and develop a suite of versatile tools that can be applied independently or in combination to support bio-innovation and combat bio-threats.

Gene editing technologies …[can] selectively disable cancerous cells in the body, control populations of disease-spreading mosquitos, and defend native flora and fauna against invasive species, among other uses. The potential national security applications and implications of these technologies are equally profound, including protection of troops against infectious disease, mitigation of threats posed by irresponsible or nefarious use of biological technologies, and enhanced development of new resources derived from synthetic biology, such as novel chemicals, materials, and coatings with useful, unique properties.

Achieving such ambitious goals, however, will require more complete knowledge about how gene editors, and derivative technologies including gene drives, function at various physical and temporal scales under different environmental conditions, across multiple generations of an organism. In parallel, demonstrating the ability to precisely control gene edits, turning them on and off under certain conditions or even reversing their effects entirely, will be paramount to translation of these tools to practical applications…

Each of the seven teams will pursue one or more of three technical objectives: develop genetic constructs—biomolecular “instructions”—that provide spatial, temporal, and reversible control of genome editors in living systems; devise new drug-based countermeasures that provide prophylactic and treatment options to limit genome editing in organisms and protect genome integrity in populations of organisms; and create a capability to eliminate unwanted engineered genes from systems and restore them to genetic baseline states. Safe Genes research will not involve any releases of organisms into the environment; however, the research—performed in contained facilities—could inform potential future applications, including safe, predictable, and reversible gene drives….

A Harvard Medical School team led by Dr. George Church seeks to develop systems to safeguard genomes by detecting, preventing, and ultimately reversing mutations that may arise from exposure to radiation. This work will involve creation of novel computational and molecular tools to enable the development of precise editors that can distinguish between highly similar genetic sequences. The team also plans to screen the effectiveness of natural and synthetic drugs to inhibit gene editing activity.

A North Carolina State University (NCSU) team led by Dr. John Godwin aims to develop and test a mammalian gene drive system in rodents. The team’s genetic technique targets population-specific genetic variants found only in particular invasive communities of animals. If successful, the work will expand the tools available to manage invasive species that threaten biodiversity and human food security, and that serve as potential reservoirs of infectious diseases affecting native animal and human populations….

A University of California, Berkeley team led by Dr. Jennifer Doudna will investigate the development of novel, safe gene editing tools for use as antiviral agents in animal models, targeting the Zika and Ebola viruses. The team will also aim to identify anti-CRISPR proteins capable of inhibiting unwanted genome-editing activity, while developing novel strategies for delivery of genome editors and inhibitors….

A University of California, Riverside team led by Dr. Omar Akbari seeks to develop robust and reversible gene drive systems for control of Aedes aegypti mosquito populations.

Excerpts from Building the Safe Genes Toolkit, DARPA Press Release, July 19, 2017

Biodiversity: the wild relatives of crops

“Crop wild relatives”—the wild ancestors of cultivated plants—are a valuable weapon in the fight against hunger. Together with varieties used by traditional farmers, they contain a wealth of genetic diversity. Yet they are under-researched and under-collected. With their survival threatened by population growth and environmental damage, the race is on to find them before it is too late.

Climate change is expected to cause higher temperatures and more frequent droughts, changing the distribution of pests and diseases. Population growth will add to the pressure on productive land: the UN expects the number of people in the world to rise from 7.3 billion today to 9.7 billion by 2050. …Dependence on a few staples worsens the consequences of any crop failure. Just 30 crops provide humans with 95% of the energy they get from food, and just five—rice, wheat, maize, millet and sorghum—provide 60%. A single variety of banana—Cavendish—accounts for 95% of exports. A fast-spreading pest or disease could see some widely eaten foodstuffs wiped out.

That makes it even more important to preserve the genetic diversity found in crop wild relatives and traditional varieties as an insurance policy. Alas, much of it has already disappeared. The FAO estimates that 75% of the world’s crop diversity was lost between 1900 and 2000. As farming intensified, commercial growers favoured a few varieties of each species—those that were most productive and easiest to store and ship.

According to Cary Fowler of the Global Crop Diversity Trust, an international organisation based in Germany, in the 1800s American farmers and gardeners grew 7,100 named varieties of apple. Today, at least 6,800 of them are no longer available, and a study in 2009 found that 11 accounted for more than 90% of those sold in America. Just one, “Red Delicious”, a variety with a thick skin that hides bruises, accounts for 37%.

Seed banks are the best hope of preserving those that remain. Dehydrating and freezing seeds means that they can be kept for hundreds, perhaps even thousands, of years, and still sprout when given light and water (as botanists need to do on occasion). Some 7.4m samples are already in seed banks around the world, but huge gaps exist.

As part of a study to be published later this year, Colin Khoury and Nora Castañeda-Álvarez of the International Centre for Tropical Agriculture (CIAT), a research facility in Colombia, studied the state of conservation of more than a thousand crop wild relatives in seed banks. They found that for over 70% there were either too few samples for safety or none at all.

The Millennium Seed Bank (MSB) in Sussex, part of Britain’s Royal Botanic Gardens, is the world’s largest wild-plant seed bank, housing 76,000 samples from more than 36,000 species. It co-ordinates “Adapting Agriculture to Climate Change”, a $50m, ten-year international programme funded by Norway to collect and store wild relatives of 29 important crops, cross them with their domesticated kin and share the results with breeders and farmers. Its freezers are solar-powered and its vault is built to withstand a direct hit by a plane (Gatwick airport is close by). Other seed banks are more vulnerable. Staff at the International Centre for Agricultural Research in the Dry Areas, an institute once based in Syria, now found in Lebanon, shipped 150,000 samples to save them from being damaged in the former country’s civil war; seed banks in Afghanistan and Iraq have been destroyed. The Philippines lost one to fire.

Located in Cali, Colombia’s third-largest city, CIAT is home to more than 300 scientists. It has a mandate from the UN to protect, research and distribute beans and cassava, staple foodstuffs for 900m people around the world. Its seed bank, housed in a former abattoir, contains over 36,000 samples of beans, more than any other seed bank, and varieties developed there feed 30m people in Africa.

For many years CIAT’s researchers concentrated on creating varieties that could cope with poor soils and drought. But they have now turned their attention to heat resistance. Earlier this year they announced that they had found heat resistance in the tepary bean, a hardy cousin of the common bean cultivated since pre-Columbian times in northern Mexico and America’s south-west. Crosses with commonly cultivated beans such as pinto, black and kidney beans show potential to withstand temperatures up to 5°C higher than those common varieties can cope with. Even a lesser increase in heat resistance, of 3°C, would mean beans could continue to be cultivated in almost all parts of central and eastern Africa, says Steve Beebe of CIAT’s bean-breeding programme…

The International Treaty on Plant Genetic Resources for Food and Agriculture, which came into effect in 2004 and has been signed by 135 countries and the European Union, identifies 35 food crops that are considered so important to global food security and sustainable agriculture that their genetic diversity should be widely shared. But it has worked less well than hoped. In 2013 a group of Norwegian researchers sent letters to 121 countries requesting seeds. Only 44 complied. Communication broke down with 23 and 54 did not even reply.

If a big crop were to fail, a single useful gene lurking in one wild relative could prevent calamity. PwC, an accountancy firm, values the genes derived from the wild relatives of the 29 crops regarded as most important by the MSB at $120 billion. Preserving the genetic diversity that remains would be an excellent investment.

Agricultural Biodiversity, Banks for Bean Counters, Economist, Sept. 12, 2015, at 54