Fungal endophytes relieve the growth-defence trade-off of their plant hosts through the production of bioactive alkaloids.

Fungal endophytes produce alkaloids that alleviate the growth-defense trade-off in plants, with AR37 strains increasing alkaloid levels and plant resistance.

• Why it matters: Understanding how plants balance growth and defense is crucial for improving crop resilience and productivity. The role of fungal endophytes in mediating this trade-off remains underexplored.
• What they did: Researchers applied gibberellin to Lolium perenne plants with and without Epichloë endophytes, then challenged them with aphids, analyzing alkaloid production, gene expression, and soil microbiota.
• The result: AR37-derived alkaloids were key in relieving the trade-off, maintaining plant resistance despite growth promotion, and influencing plant hormone levels and soil microbial communities.