What role do mycorrhizae play in plant nutrient uptake?

Mycorrhizae are beneficial symbiotic associations between fungi and plant roots that significantly enhance nutrient uptake. The correct choice highlights their role in increasing the surface area available for absorption.

Mycorrhizal fungi connect with plant roots and extend their hyphae into the soil, reaching areas that roots alone cannot access. This fungal network not only increases the surface area for absorption of water and essential nutrients, such as phosphorus, but also facilitates the movement of these elements from the soil into the plant. Beyond nutrient uptake, mycorrhizae can help improve soil structure and enhance water retention, further benefitting plant health and growth.

In contrast, the other options do not accurately represent the beneficial role of mycorrhizae. They do not inhibit nutrient absorption or form barriers around root systems, as these actions would be detrimental to plant growth. Additionally, while mycorrhizae do contribute to nutrient storage in the soil, their primary function is to aid in the active absorption of nutrients, rather than solely storing them.