This research explores how beneficial fungi live inside grass plants without causing harm. The study reveals that two similar proteins (Cdc42 and RacA) help the fungus grow properly within plant tissues. Understanding this relationship is important because it shows how some microorganisms can live harmoniously with plants instead of causing disease. Impacts on everyday life: – Helps develop better grass varieties for agriculture and lawns by understanding beneficial fungal partnerships – Provides insights for developing more sustainable agricultural practices using beneficial microbes – Could lead to new approaches for protecting plants from harmful fungi – May help in developing stress-resistant grass varieties for sports fields and golf courses – Contributes to understanding how organisms maintain beneficial relationships rather than causing disease