Mycorrhizae free essay sample

Mycorrhiza is a specialized fungus in the soil which forms close associations with the roots of a vascular plants * In other temperate and boreal successional systems arbuscular mycorrhizal fungi are the primary mycorrhizal associate in early succession, whereas in older soils the main associates are ectomycorrhizal fungi (Piotrowski, 2008). Arbuscualar Mycorrhizae: Arbuscular mycorrhiza (AM) is the predominant and ancestral type of mycorrhiza in land plants. It’s root cells have arbuscules (tree like structure, highly branched hyphae inside plant cells) and vesicles in most species Its occurrence in a vast majority of land plants and early-diverging lineages of liverworts suggests that the origin of AM probably coincided with the origin of land plants. Classes include Archaeosporales, Diversisporales, Glomerales, Paraglomerales, part of the phylum Globermycota, and part of the kingdom fungi (species grow Arbuscular Mycorrhizae) * Fossil evidence and DNA sequence analysis by mycologists show arbuscular mycorrhizae first appeared approximately 400-460 million years ago. We will write a custom essay sample on Mycorrhizae or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Arbuscular mycorrhizas are found in 90% of all plant families, and occur in many crop species. How it Works: * Plant nutrients which are concentrated with nutrients are taken by hyphae and then released into the root cells of vascular plants. Nutrients can also be stored in the root of the fungus and used in the future when the nutrients are needed, such as low temperatures or season fluctuations. * Arbuscular mycorrhizas are mycorrhizas whose hyphae enter into the plant cells, producing balloon-like vesicles or dichotomously-branching arbuscules. Arbuscular mycorrhizae are known to be heterkaryon, goining through both asexual and sexual reproduction. * The hyphae of arbuscular mycorrhizal fungi produce the glycoprotein glomalin, which may be one of the major stores of carbon in the soil. Arbuscular mycorrhizal fungi have (possibly) been asexual for many millions of years and, unusually, individuals can contain many genetically different nuclei (a phenomenon called heterokaryosis). * The fungal hyphae do not in fact penetrate the protoplast (i. . the interior of the cell), but invaginate the cell membrane. The structure of the arbuscules greatly increases the contact surface area between the hypha and the cell cytoplasm to facilitate the transfer of nutrients between them. Ectomycorrhizae * Ectomycorrhizas, or EcM, are typically formed between the roots of around 10% of plant families, mostly woody plants including, eucalyptus, oak, pine, and rose * Families and fungi belonging to the Basidiomycota, Ascomycota, and Zygomycota. Ectomycorrhizas consist of a hyphal sheath, or mantle, covering the root tip and a hartig net of hyphae surrounding the plant cells within the root cortex. In some cases the hyphae may also penetrate the plant cells, in which case the mycorrhiza is called an ectendomycorrhiza. Outside the root, the fungal mycelium forms an extensive network within the soil and leaf litter. Nutrients can be shown to move between different plants through the fungal network. Carbon has been shown to move from paper birch trees into Douglas-fir trees thereby promoting succession in ecosystems. Benefits of Mycorrhizae * AMF affect phosphorus cycling, aid seedling establishment of many plant groups, help maintain plant diversity, and strongly contribute to soil stabilization and carbon storage through soil aggregate formation * Experiments have shown mycorrhizas can increase the uptake of plant nutrients such as nitrogen and phosphorous when they are at low concentrations or in insoluble form in the soil * Improve crops without being indispensible * Make nutrient uptake from poor soil more resourceful Mycorrhizas can increase the absorption of plant nutrients when they are at low temperatures or insoluble in the soil * The plant supplies the fungus with carbon compounds, including hexose sugars which are sugar alcohols which increases the plant cell permeability. * Carbon can be transferred between plants because mycorrhizae grow and attach to many different roots of plants of different species