This is what wikipedia says...also learned about it in college...Mycorrhizae
A mycorrhiza is the result of a
mutualistic association between a fungus and a plant. This
mutualism takes place at the root level, where individual
hyphae extending from the
mycelium of a
fungus colonize the
roots of a host
plant, either intracellularly or extracellularly. it makes them have more cells. This
mutualistic association provides the fungus with a renewable source of food through access to fixed carbon (sugars) from the plant photosynthate. These are translocated to the root tissues from their source location (usually leaves), and then to the fungal partners. In return, the plant gains the use of the mycelium's tremendous surface area to absorb mineral nutrients from the soil. It is believed that the mycelia of mycorrhizal networks have better mineral absorption capabilities compared to plant roots. An example of this is the manner in which
phosphate ions are tightly bound to
iron oxides in many soils. Plant roots are generally incapable of accessing these phosphorus sources (which can be large and are termed sinks), yet mycorrhizal mycelia can access these forms of phosphorus. The mechanisms of increased absorption are both physicalmycorrhizal mycelia are much smaller in diameter than the smallest root hair and thus are able to explore a greater volume of soil and have a much larger surface area for absorptionand chemicalthe cell membrane chemistry of fungi is different from that of plants. Mycorrhizae are especially beneficial for the plant partner in nutrient poor soils. Furthermore, mycorrhizal plants are often more resistant to diseases, such as thoThe
cytoplasmic streaming of the mycorrhizal hypha is a mechanism that facilitates the transfer of nutrients from the soil, at relatively remote distances from the root, to the root at rates far exceeding those that would be possible by
osmotic flow alone. This has an energy cost to the fungus. In return, the mycorrhizal fungus is rewarded by the "payment" of nutrients in the form of
sugars,
starches,
proteins and
lipids from the plant roots. These nutrients, in turn, flow to the whole mycelial network through cytoplasmic streaming.
Mycorrhizas form a
mutualistic relationship with the roots of most plant species (although only a small proportion of all species have been examined, 95% of all plant families are predominantly mycorrhizal). Plants grown in sterile
soils and growth media often perform poorly without the addition of
spores or hyphae of mycorrhizal fungi to colonise the plant roots and aid in the uptake of soil mineral nutrients. The absence of mycorrhizal fungi can also slow plant growth in early succession or on degraded landscapes.