Plant hormones may offer a way to balance crop yield and disease resistance

Plants face a constant struggle between growth and immune response, with hormones playing a crucial role in managing this delicate balance. At the Technical University of Munich, researchers have uncovered a mechanism involving plant steroid hormones that can suppress immune responses and allocate resources towards growth. Normally, in the absence of pathogens, plants keep their immune systems inactive to concentrate on growth.

Steroid hormones achieve this by inhibiting specific immune receptors, ensuring they remain inactive until required. When a plant encounters a pathogen, functional receptors are necessary to initiate defense mechanisms, prompting the inactivation of steroid hormone-regulated transcription factors to allow receptor assembly and commence defense responses, albeit at the expense of reduced growth.

This discovery, specifically observed in the model plant Arabidopsis thaliana upon infection with a powdery mildew pathogen, marks the first identification of this steroid hormone-controlled mechanism. The researchers were astonished by the transcription factor's role in altering DNA modifications, which indirectly influences the production of receptor variants.

Should future breeding programs capitalize on this mechanism, it could potentially lead to the development of high-yielding crop varieties that are more resilient to diseases.