Researchers from the University of Illinois have identified the genes and
metabolic pathways which are responsible for safener efficacy in grain
sorghum. Safeners, serendipitously discovered in late 1940's are chemicals
that selectively protect certain crops from damage.
The researchers' first step in understanding how safeners work is to look
into what happens inside the cells of cereal crops when exposed to safeners.
In previous trials with grain sorghum, the team noticed a massive increase
in glutathione S-transferases (GSTs), enzymes that quickly detoxify
herbicides and other foreign chemicals before they can cause damage.
The team used genome-wide association study. They grew 761 grain sorghum
inbred lines in a greenhouse and compared plants treated with safener only,
herbicide only, or both safener and herbicide. They found specific genes and
gene regions that were switched on in the safener-treated plants, and they
were genes that coded for two GSTs. Sorghum is also known to produce
allelochemicals, including dhurrin, a chemical with a cyanide group. The
research group also found that some genes involved in dhurrin synthesis and
metabolism were triggered in response to safeners too.