How does the Sm1 gene work?
When the insect begins to feed on the seed, the Sm1 gene causes the level of phenolic compounds (naturally occurring organic acids in wheat kernels) to elevate more rapidly than in wheat kernels without the Sm1 gene. The higher levels of phenolic acids cause the midge larvae to stop feeding and the larvae starve to death. The mechanism that triggers the production of phenolic acids does not operate if midge larvae are not feeding on the seed, and in addition, these acids are gone by the time wheat reaches maturity — thus not affecting the quality or food value of the harvested grain.
