GM maize has built-in SOS chemical

MAIZE has been genetically engineered to produce a chemical rallying cry for help against the plant's worst pest in the US.

The signal is an odorous chemical called (E)-beta-caryophyllene. It attracts nematodes that kill the larvae of the western corn rootworm, responsible for an estimated $1 billion in lost revenue in the US every year.

Ted Turlings of the University of Neuchâtel in Switzerland and his colleagues inserted a gene from oregano that codes for caryophyllene into maize plants.

"We saw a 50 per cent drop in damage to the engineered plants, compared with the controls. It was quite dramatic," he says.

Turlings's team is now looking into creating super-resistant maize by inserting the gene for caryophyllene into plants that are already engineered to produce the Bt toxin against rootworms.