US scientists are investigating genetically modified viruses so that they can modify the DNA of crops. To spread the virus, they would use various insect species that are also modified. The declared objective of the program, financed by the military, is to protect the crops from a sudden drought, frost … or an external attack. However, a group of scientists now warns that insects with mutant viruses could become an uncontrolled biological weapon.
The Defense Advanced Research Projects Agency (DARPA), which belongs to the US Department of Defense, announced its idea to turn harmful insects into allies in 2016, although it was not until the end of last year when the four projects selected for the Insect Allies program were announced. Everything in them is science and extreme technologies, on the edge of science fiction.
The four investigations run in parallel and all have the same three elements: a virus or bacteria, an insect and a target plant. In the one led by researchers from the Penn State University, for example, they want to use viruses of the genus Begomovirus, which attacks crops such as tomato, to protect plants from inclement weather. The intention is, after neutralizing your viral load, to add a certain plant gene that expresses a protective feature, such as more resistance to cold. To spread the virus, they plan to use one of the worst pests of the tomato, the white fly.
The program is funded by DARPA, the research agency of the US Department of Defense.
"Now, a farmer can not do much to save his crop if weather forecasts predict a severe drought for next month," said Penn State project leader Wayne Curtis, after being one of those selected by DARPA. "Although we can develop a variety of plant that will withstand a type of stress, the nature of new diseases and pests threatens to overcome the improvements provided by traditional breeding and genetic modifications, we seek to develop a technology for rapid response that allows the distribution of genes that protect plants when they need it once planted, "he added.
That rapid reaction is one of the great novelties of Insect Allies. Until now, plant varieties with a certain improvement need years to develop and, once achieved, add it to the seeds for the next season. Here they intend to insert it in already adult plants. It would then be a horizontal transfer, not vertical. Another innovation is the use of the CRISPR gene editing technique to modify the target plant gene with the help of the virus. Regarding the manipulation of insects, although there have been no details of how, there are already experiments that have achieved in a process of forced evolution called directed genetics.
"Insect Allies has little to do with genetics because it proposes using insects to transmit mutations to crops, not members of the same species," recalls the biologist at the Max Planck Institute for Evolutionary Biology (Germany), Derek Caetano. Anollés. "Anyone who has been concerned with targeted genetics should be much more concerned with Insect Allies," he adds.
Along with other European biologists, Caetano-Anollés has published in the magazine Science a document that warns about the risks involved in the DARPA program. The article is part of a larger initiative that seeks to dismantle Insect Allies before it can succeed. The authors acknowledge that this type of technology could have many positive uses but also a dual use: biological warfare.
"What worries us is that the Insect Allies technology can be very easily converted into a weapon, but even worse, it can be done in an extremely covert way and very difficult to track: Insects can be designed to infect an enemy's crops, killing the plants or sterilizing their seeds and no one would know what had happened until the next campaign, "says Caetano-Anollés.
Therefore, another of the criticisms that these biologists make to the plans of DARPA is its fixation in which insects are used precisely to spread the viruses. For the authors of the paper, there are technologies of mechanical dispersion as or more effective and more controllable than the release of thousands or millions of insects with a virus in tow. But the main complaint they make is that Insect Allies can be the excuse for other countries to develop their own programs based on Insect Allies. As the Max Planck biologist says: "In the worst case, this may already be happening and the US has already opened the Pandora's box that will change the war forever no matter whether the DARPA program ends up working or not. "
The great advantage of Insect Allies is that genetic changes in plants would take effect immediately
From the US agency they recognize the risk of a possible double use of technology, something that, they consider, always accompanies a new technology like this one. Still, the director of Insect Allies, the entomologist Blake Bextine defends his program from the rest of the criticism remembering the goal to create it: "DARPA created Insect Allies to offer new capabilities to protect the US, in particular to respond quickly to threats to the food supply, "says Bextine.
The Insect Allies program, initiated last year, selected four different projects involving scientists from various universities in the United States. There is hardly any detailed information about them and only the leaders of two of the projects have answered the questions of this newspaper.
In addition to Penn State's tomato and whitefly project (see main text), two others work with corn, the main product of US agriculture. One of them, driven by molecular biologists and entomologists at Ohio State University, aims to rescue corn plants once they are attacked by pathogens by manipulated viruses. For this, they still have to identify which genes of the plant to act on.
Only one of the projects, the one led by the molecular biologist at the University of Texas at Austin, Jeffrey Barrick, does not use viruses to modify plants. In this case, they investigate with a host bacterium of a pulgón that attacks the beans. In the case of the Boyce Thompson Institute, they have four years (and three) and 10 million dollars for their VIPER project. They are working with leafhoppers in the cultivation of corn.
An essential element of the program is security. Each of the four projects has to devise a security key for each element of the system (virus, insects and plant) that can be activated in an emergency, or that limits the geographical or temporal scope of its effects. Among the measures is the release of sterile insects or with a shorter life span. They are even investigating that the advantage acquired by the plant thanks to the virus is temporary.
Georg Jander, head of the VIPER project, explains one of the possible security measures: "Certain genes in viruses are necessary only for transmission by insects, but not for their replication and infection of plants. If one gets a genetically modified plant that expresses that gene, the virus can make use of the encoded protein and be transmitted by insects. However, if the insect transmits the virus to an undesigned plant, for example, in a field of corn, the virus can infect the plant, but it can not be retransmitted. "