Published: 4 August, 2009, 14:14
Edited: 29 July, 2010, 07:22
A team of European and US researchers have modified the maize genome so that the plant emits a chemical compound which attracts nematode worms, which in turn kill pests damaging the crops.
The method was tested by the University of Missouri's Bradford Research and Extension Center in Columbia, reports Nature magazine.
The scientists have switched on a gene that regulates production of (E)-β-caryophyllene in maize. The chemical is an attractant for nematodes, which feed on western corn rootworm, an insect whose larvae damage maize roots. The rootworm is one of the most dangerous corn pests inhabiting North America.
The chemical is produced naturally by some maize varieties, but selective breeding of the commercial variety left most of them without the ability. Researchers used a gene manipulation technique, which they’ve filed a patent for, to insert the missing gene. A field test on a field where transgenic and normal maize was infested with rootworm parasites showed less root damage and 60% fewer adult insects on the experimental plants.
The method may be a more efficient and environmentally friendly alternative to spraying crops with pesticides. The big challenge for scientists, however, is to identify compounds, which plants should produce to lure the pests’ natural enemies.
Meanwhile, the team is to focus on making maize produce (E)-β-caryophyllene only when it is actually attacked with rootworms and not continuously. This will allow nematodes to be led to plants that actually need protection, rather than one particular organism.