Roles of Mycorrhizae Research Paper Example | Topics and Well Written Essays - 5000 words

Roles of Mycorrhizae - Research Paper Example The roots provide the microorganisms a stable access to nutrition. In return, the roots benefit from the high water and mineral absorptive capacity of mycelia resulting from its relatively small size and subsequent better ability to penetrate soil. As a result, mycorrhizal plants are more resistant to lack of water. They are more capable of colonizing barren land or unfamiliar territory than plants without mycorrhizae do. In addition, mycorrhizal fungi process demineralized phosphates such that the minerals will be available for plant use. However, as is the case in all biological interactions, not all mycorrhizae are mutualistic. In cases in which nutrients are abundant in the plant’s environment, association with microorganisms, as is what happens during mycorrhizal formation, may be more parasitic than beneficial (Bucher, 2007). However, current agricultural practices prevent the formation of these mycorrhizae. The pesticides being used have a non-discriminating adverse eff ect on the microorganisms living in the plants’ ecosystem. ... Its functions, particularly in providing nutrients and protecting the plants against salt stress and drought, are then enumerated. Its relationships with various members of its ecosystem are then discussed. Finally, the importance of these knowledge in terms of what aspects should be focused on will be suggested. DEVELOPMENT Endomycorrhizae development Figure 1 illustrates the development of endomycorrhizae. The fungal species associated with endomycorrhizae reproduce asexually. They undergo an asymbiotic phase in which spores germinate and hyphal growth are limited without the nutrients supplied by the host plant. Soon after, hyphal growth begins. This presymbiotic phase is induced by the presence of plant root exudates, which fungal hyphae penetrate to (Bucher, 2007). At the root surface, the fungal hypha develops a set of penetrating cells and is now called a hyphopodium. This now enters the root epidermis, continuing to grow into the outer, and then the inner root cortex. It then spreads intercellular along the longitudinal axis of the root. This structure of the fungus is the one called an arbuscule (Gutjahr et al., 2008). The peak of fungal development is characterized by the development of an extraradical mycelium that is able to produce and exude spores for colonization of other plants (Bucher, 2007; Frey-Klett et al., 2007). However, the development of arbuscular mycorrhizae is not synchronous, in that various colonization stages are present in one plant (Gutjahr et al., 2008). Figure 1, previous page. Development of Endomycorrhizal Development. From Bucher, Marcel, 2007. Tansley review: Functional biology of plant phosphate uptake at root and mycorrhiza