Wallflower species that produce high levels of glucosinolates also contain higher levels of myrosinase, the enzyme that converts these compounds into toxic products when the plant is damaged. The co-evolution of these two traits is thought to have occurred as a result of natural selection, as plants that produce both glucosinolates and myrosinase are better able to deter herbivores than plants that produce only one of these compounds.

The production of glucosinolates and myrosinase is regulated by a complex network of genes. In recent years, researchers have identified several key transcription factors that control the expression of these genes. These transcription factors are themselves regulated by environmental cues, such as light, temperature, and the presence of herbivores.

The co-evolution of glucosinolates and myrosinase is a fascinating example of how plants have evolved to defend themselves against herbivores. This arms race between plants and herbivores has been going on for millions of years, and it has resulted in the evolution of a wide variety of plant defense mechanisms.