Abstract:

The word symbiosis has shown to be quite effective in describing the interaction between the two different species present in lichens, since it entails the primary attribute of living in a synchronized and well-mixed fashion so as to create a single biological unit. When the algal partner (photobiont) absorbs moisture and carbon dioxide from the atmosphere through the tissues of the mycobiont, it acts as a heterotroph and the fungus (mycobiont) gain photosynthetic products from the algae. It has been demonstrated physiologically and ultrastructurally that the fungus parasitizes the algae in a regulated manner, and in a few cases, kills the algal cells, making lichen relationships an example of commensalism or even parasitism, depending on the species. For the most part, lichenized fungi are ecologically obligatory biotrophs yet physiologically flexible. In lichens the mycobiont accounts for most of the thallus's volume and provides the lichen's form, structure, and color, with some help from the algae. As a result, lichens are classified according on how their mycobionts are classified, and are not traditionally considered to be a distinct taxonomic category. Less than half of all ascomycetes and one-fifth of all fungus live in lichens

Description:

Unveilin, Hidden World, Lichens, word symbiosis