Mutated plants can grow in TNT-toxic soil
Aaron Burden/U.S. Navy

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Mutated plants can grow in TNT-toxic soil

When the explosive chemical trinitrotoluene (TNT) detonates, the destruction continues to spread even after the blast. TNT particles seep into the dirt below, poisoning the soil for plant life. When grown in TNT-laden areas, which include old mines, waste sites, and military conflict zones, plants absorb and remove the toxic chemicals from the soil through their roots in a process known as remediation. But their labor is an act of sacrifice: When most plants soak up TNT, a harmful chemical reaction occurs in the energymaking mitochondria of the plant’s cells, stunting its growth dramatically and eventually killing it. But researchers report today in Science that they have discovered a novel mutation in the weed Arabidopsis thaliana that shields it from harmful reactions with TNT. The mutation—in the MDHAR6 gene—allows the plant to remove TNT from the soil with little to no damage. Researchers report that MDHAR6 mutant plants have long roots and bushy leaves, compared with other plants exposed to TNT. They hope that exploiting this mutation could lead to a new type of herbicide, which would kill unwanted weeds not engineered with the MDHAR6 adaptation. For now, it simply protects those plants lucky enough to have it.