What is the role of mycorrhizal fungi in plant health?

Mycorrhizal fungi play a crucial role in plant health primarily by enhancing nutrient uptake and increasing resistance to pathogens. These fungi form symbiotic relationships with plant roots, extending the root system's surface area through their hyphal networks. This expanded surface area allows for improved absorption of essential nutrients, particularly phosphorus, which is often limited in soil.

Additionally, mycorrhizal fungi help plants access other nutrients like nitrogen, potassium, and trace elements, promoting overall growth and vigor. Beyond nutrient uptake, these fungi also enhance plant resistance to certain pathogens. They can outcompete pathogens for space and resources and may even induce systemic resistance in plants, allowing them to better defend themselves against diseases.

While the other choices mention processes and functions that may be related to plant biology, they do not specifically encapsulate the primary roles of mycorrhizal fungi.