Recent research has revealed something unexpected happening in the soil beneath our feet. Scientists have discovered that a beneficial fungus called Serendipita indica can send molecular messages to plant roots, helping them grow and resist stress. This finding by Nasfi and colleagues shows how the fungus produces small RNA molecules that travel into plant cells to coordinate their partnership – a sophisticated form of cross-kingdom communication that influences plant growth in gardens and fields worldwide.

The research reveals a molecular conversation happening between fungi and plants. When Serendipita indica colonises plant roots, it produces small RNA molecules that act like precise biological signals. These fungal messages help regulate important plant processes, including how cells build their walls and respond to hormones. Most remarkably, the study shows these RNA molecules are actively transported into plant cells through specific cellular machinery, demonstrating a sophisticated system of cross-kingdom communication.

To understand how fungi and plants share molecular messages, the research team grew the Serendipita fungus alongside roots of Arabidopsis, a small flowering plant widely used in botanical research. Using specialised tools that can track tiny RNA molecules, they followed the journey of fungal messages into plant cells. The team used genetic analysis to identify which messages were being sent, while microscope imaging revealed where and when these exchanges occurred. This approach helped show the detailed mechanics of how fungi share information with their plant partners.

This discovery adds an important piece to our understanding of how plants and beneficial fungi work together in nature. While scientists already knew that disease-causing fungi could use RNA messages to harm plants, finding this same language used in beneficial relationships reveals new aspects of plant partnerships. These insights into how friendly fungi help plants thrive could lead to more sustainable ways of supporting plant growth.

Nasfi, S., Shahbazi, S., Bitterlich, K., Šečić, E., Kogel, K-H., & Steinbrenner, J. (2024). A pipeline for validation of Serendipita indica effector-like sRNA suggests cross-kingdom communication in the symbiosis with Arabidopsis. Journal of Experimental Botany. https://doi.org/10.1093/jxb/erae515 ($)

Cross-posted to Bluesky, Mastodon & Threads.

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