Unlocking nature’s arsenal: Engineering grasses for insect defense and livestock palatability

The defensive alkaloid gramine, present in barley and other grass species, plays an important role in protecting the plant from insect damage but poses challenges for ruminant palatability. Breeding strategies balance these factors by maintaining the protective function and making the grain palatable for grazing animals. In this study, Dias et al. used pan-genome sequencing to identify a gramine biosynthesis gene cluster in barley. They further characterized an enzyme responsible for the intricate oxidative rearrangement of tryptophan. Through the adjustment of gramine levels in yeast and various plant species, the authors demonstrated that gramine-related traits could be optimized. This study represents a big step forward in understanding grass defenses for agricultural improvement. (Summary by Yueh Cho @YuehCho1984) Science. 10.1126/science.adk6112.