Scientists from the University of Cologne’s CEPLAS Cluster of Excellence on Plant Sciences have unveiled the secret strategies employed by fungi to invade plant roots. By identifying two particular fungal enzymes that manipulate a plant’s immune system, these groundbreaking findings pave the way for potential advancements in both medical and agricultural fields. This research has been published in the journal Cell Host & Microbe.
In the natural world, plants and fungi share a complex relationship, with fungi often colonizing plant roots. This interaction can either be mutually beneficial, with both organisms gaining advantages, or pathogenic, where the fungi harm the host plant. A research team led by Professor Dr. Alga Zuccaro at the CEPLAS Cluster of Excellence has shed light on how the beneficial root fungus Serendipita indica successfully invades the roots of the Arabidopsis thaliana, a model plant.
Initially, this fungus takes over the living root cells. Then it triggers a controlled cell death within the host plant, enabling it to establish itself without causing significant damage. The exact mechanisms controlling this plant cell death have long remained a mystery. However, the team uncovered that Serendipita indica secrets two enzymes, NucA and E5NT, which generate the molecule deoxyadenosine (dAdo). This molecule instigates regulated cell death in plants, thus allowing the fungus to infiltrate the root system.
The researchers discovered that dAdo is initially produced in the apoplast, a region outside the host cells. It then infiltrates the plant cell via the membrane transporter ENT3, where it effectively takes over the host’s immune system, leading to cell death. Interestingly, this phenomenon, as outlined by Professor Zuccaro’s team, is not limited to plants. A similar process can be observed in humans during interactions between the pathogenic bacterium Staphylococcus aureus and human immune cells.
‘Our research showed that the beneficial root fungus Serendipita indica uses two enzymes, similar to S. aureus, to generate dAdo, which induces cell death and enables successful root colonization. This suggests that this mechanism is a common strategy across different microbes and lifestyles,’ stated Professor Alga Zuccaro. These findings emphasize the crucial interplay between microbial colonization and the host’s immune metabolism, opening new avenues for strategic interventions in medicine and agriculture. ‘By understanding these shared mechanisms, we can devise more effective ways to manage both harmful and beneficial microbes in human health and crop production,’ she added.
