It takes a lot of water, light, nutrients, and energy for any sort of plant to grow. But there is an easier way for plants to grow! By forming relationships with certain beneficial fungi, plants can benefit and grow faster. Mycorrhizal fungi are a type of beneficial fungus that form symbiotic relationships with plants. Mycorrhizae live in the roots of the plants. The fungus will attach to the roots. Then the fungus expands into the surrounding soil. The connecting filaments create a vast network that is basically then able to act as a second root system for the plant.
Mycorrhizae exist as microscopic filaments and threads that extend throughout the soil. These are called hyphae. Hyphae make up the vegetative part of a fungus called mycelium. Microscopic threads from the mycorrhizae can be hundreds or even thousands of miles long! All of these little threads are packed into a small area underneath the plant in the roots.
How Plants and Mycorrhizae Help Each Other
The roots of plants need to be in direct contact with the individual soil particles to really benefit from nutrients in the soil. The problem is, plant roots are relatively large in comparison with the tiny particles of soil. The tiny hyphae of the mycorrhizae are so tiny that they can cover every bit of soil and squeeze in between the tiny particles. An increased coverage of surface area allows the plant to access more of the nutrients than they could get with just their roots. The mycorrhizae pick up nutrients from the soil and deliver them back to the roots of the plant.
So what do the mycorrhizae get out of the relationship? Plants produce their own food through photosynthesis. Excess carbohydrates that are produced by plants are sent to the roots. From there, the mycorrhizae are able to gain access to these excess nutrients from the plant. Mycorrhizae can pull some nutrients from the soil but they really rely on plants to help them out to get all the nutrients they need.