Darpa, the research arm of the US military, is embarking on a radical new trial, but researchers warn that the technology could be turned into a biological weapon
By Matt Reynolds | 4 October 2018
WIRED — Making crops taller, tastier, and more resistant to disease is a tedious process. For thousands of years, the only option farmers had was to pick two plants that showed particularly desirable characteristics and breed them together, hopefully creating offspring that shared those promising traits and avoided undesirable ones.
Modern gene-mutating techniques sped up this process. First, researchers worked out that by bombarding embryonic cells with radiation, they could force mutations in plant genomes, causing desirable traits to occur at random. They could then pull out these mutated cells and use them to generate entirely new plant lines.
In 2012, the geneticists Emmanuelle Charpentier and Jennifer Doudna found a much more precise way of changing a plant’s genome. CRISPR-Cas9 is a kind of molecular pair of scissors that can be guided to a precise point in an organism’s genome to chop out a troublesome gene, or insert a desirable one. In the agricultural world, CRISPR is already being used to create non-browning mushrooms, easy to harvest tomatoes and bananas that are resistant to certain diseases.
CRISPR is much faster and more precise than the selective breeding techniques used a hundred years ago. But the process requires a number of intricate steps. First, embryonic plant cells must be exposed to the CRISPR-Cas9 molecule so the editing can take place. Only a tiny percentage of them will be edited, and those lucky cells must be grown into full-sized plants which then – if everything goes to plan – will show the desirable trait that the researchers were trying to code for and hopefully produce seeds or clones that also carry that trait. It’s a long process that requires multiple generations of plants and exhaustive testing and experimentation at every stage.
But the US Defense Advanced Research Project Agency (Darpa), a government agency responsible for developing new technology usually for use by the military, wants to speed up this process. The agency is funding trials that, if they are successful, will mean that insects can be used to deliver genome-editing molecules to crops growing in the field. The research program, which is already underway in four different trials in the US, is now attracting consternation from biologists and ethicists who argue that this new technology poses a biosafety risk and could easily be turned into a new kind of biological weapon. It’s all part of a program called “Insect Allies” that over four years will provide $47 million (£36m) in funding to research groups trying to develop a way of using insect-delivered viruses to edit crops in the field. […]