Good Essay About Symbiosis

Symbiosis is the association between two living organisms such that both parties derive usefulness or benefits from the association. The feature is especially observable between fungi and some trees. The fungi are especially useful in deriving nitrogen from the soil and providing it to the plant. The fungi benefits from the supply of carbon form the plant. Over and above the supply of nitrogenous nutrients, the fungi also provides phosphorus to the roots of the plant. These roots (or rhizae) are the ones that form an association with useful fungi in a symbiotic relationship that results in the formation of mycorrhiza. Symbiosis closely relates to the principles of natural selection and survival of the fittest. The less fit organisms can team up to ensure they are complimentary to each other’s existence.
Scientists classify mycorrhiza into two categories: ectomycorrhiza and endomycorrhiza. The former’s proliferation of the fungi occurs on the surface of the root of the plant while in the later proliferation occurs inside the root of the plant (normally between the root and the soil). Arbuscular mycorrhiza (AM) is commonly existent in the roots of most herbaceous plants where a symbiotic relationship exists. The fungi reproduce asexually to grow on the root of the plant. The provision of nutrients to plant roots AM help to ward of pathogenic fungi. It is because of this reason that some plants retain the useful fungi even after their use is complete, for example in some fibrous root systems. AM symbiosis is very common in most plants growing in areas with nutrient shortage. This means that this relationship helps to retain plant diversity by ensuring survival of plant species under harsh environmental conditions.
The asexual stage of most of fungi of the basidiomycete family is the rhizoctonia. Different types acquire their recognition from the characteristic dolipores and the number of nuclei present in the hyphal tip. Some variations of the rhizoctonia produce sexual structures. This provides another avenue of classification of these organisms. Some symbiotic relationships indicate a stage of parasitism at some point. This is especially common in the association between orchids and fungi. The orchid plant is parasitic during its germination stage when the fungi derive no resources from the formation of mycorrhiza. Maintenance of this kind of parasitism is possible if the plant fails to fulfill its role of provision of carbon to the fungi. This is especially if the plant fails to carry out photosynthesis. Such plants are dependent on the symbiotic relation for survival since in some instances they source their carbon from the fungi, contrary to the norm. The main benefit to the fungi, in such instances, is the provision of an ecological niche. This means living in an area of the ecosystem where there is minimum competition and higher chances of survival. This means that the fungi are heterotrophic and the plant is photosynthetically inactive.
Very many species continue to exist due to the simple fact that symbiosis is an available option for survival. This is so in woody forests where symbiosis is crucial in the survival of many conifer and pine trees. Dominant forests would otherwise be non-existent if it was not for the benefits the trees derive from the symbiotic relationship. Other trees that are a source a quality timber continue to derive their existence form symbiotic relations with fungi. Such trees have the formation of mycorrhiza as an envelope on the entire root surface in place of root hairs, but with ample thickness. Once fungi receive carbon (as sucrose) from the root, they convert it to fungi-sugars. They in turn facilitate the availing of nitrogenous nutrient to the plant root. Such nutrients are scarce in such forests.
Symbiotic relations may develop between more than two organisms. Such associations may include tripartite associations where bacteria, mycorrhiza fungi and plants interact for mutual benefit of each organism. This requires an analysis and review of the interactions between fungi and bacteria. Research shows that these types of interactions are very common and widespread in various ecosystems with significant dynamism. The existence of fungi-bacterial relations and mycorrhiza-plant relations at a common point means that these tripartite interactions are real. The normal plant-fungus interaction for purposes of absorption of nutrients, such as nitrogen by the plant and carbon by the fungi, obtains supplementary functions from fungi- bacteria interactions.
Bacteria may derive nutrients from substrates derived from fungi for purposes of conversion into biomass. Bacteria attach themselves to the hyphae depending on the vitality of the fungi and the types of fungi. The bacteria, according to recent research, aid in germination of the spores of the fungi. This aids in proliferation of fungi in the ecosystems especially in harsh environmental conditions. Interactions may also exist among the bacteria and the plant. This means the existence of two or more symbiotic relations on a single plant. An example is the symbiotic relation between nitrogen fixing bacteria and the roots of leguminous plants. Another interaction may arise between AM fungi and the plant to aid in absorption of phosphorus. Bacterial-fungi relations may also arise. Some bacteria strains such as MHB aid to prevent contamination of the plant by platinum and cadmium. This is through detoxification of such harmful substances or breaking them down into simpler molecules or particles that are harmless. Other bacterial actions include inhibition of plant competitors for nutrients and increased root branching.
Bacteria may also affect the gene expression of the fungi. This is normally through adherence to the mycorrhiza fungi’s cell surface. This is normally through release of volatile organic compounds (VOCs). This results in changes in the transcription process hence altering the resultant fungi that develop. The research carried out thus far is sufficient to support the hypothesis that mycorrhiza are tripartite associations. This is despite the fact that the exact mechanisms involved are unknown. The mechanisms are still existent, nonetheless.
Researchers conclude that it is mainly due to environmental pressures and survival tactics that organisms from three different kingdoms associate in a unique kind of symbiosis. The findings also show the complexity of the mycorrhiza, their ability to be flexible and coexist with other organisms. The bacteria are now an acceptable third component in the symbiotic relation present in mycorrhiza. Sufficient findings and data are available in support of this line of thought. Endobacteria are existent in mycorrhiza especially as concerns AM fungi. All these theories of mutual co-existence between various organisms act to support the biological theories of natural selection and evolution. Adaptive and convergent radiations occur from interactions between organisms and their natural environment. Nature can construe itself to ensure its perpetuity and increased diversity.