Mycorrhizae are symbiotic associations between fungi and plant roots. They promote plant growth by absorbing inorganic nutrients, such as phosphorus and nitrogen, from the soil and transferring them to the plant. This enables the plant to grow faster and larger. The fungi also help to protect the plant from certain soil-borne pathogens and pests, which can help to prevent damage and disease. Overall, mycorrhizae serve as important partners to plants, contributing to their health and productivity in a number of ways.