Glomalin and Carbon Sequestration in Terrestrial Ecosystems

The fungi in Glomeromycota are mutualistic symbionts of plant roots and produce a special glycoprotein called “glomalin” on their spores and mycelium cell wall.

The glomalin enters adjacent soil after cell wall death and decomposition.

It contains 3–5% nitrogen and 36–59% carbon with considerable amounts of iron (0.8–8%).

Glomalin is considered a recalcitrant source of carbon.

The half-life of glycoprotein is approximately 50 years, so it has a relatively long persistence in soil.

Therefore, it could contribute to the sequestration of carbon in land-based ecosystems.

The rate of carbon flow from the plant to the underground parts and then to the fungal symbionts affects the amount of glomalin synthesis by the fungi.

The impact of different environmental factors such as nutrient availability, tillage, atmospheric CO_2 level, drought, salinity, and heavy metal toxicity stresses on carbon allocation to the fungi and its consequence on the amount of glomalin production are addressed here.

Also, the contribution of glomalin in carbon sequestration in soils is discussed.