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Mycorrhizas
A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, its root system. Mycorrhizae play important roles in plant nutrition, soil biology, and soil chemistry. In a mycorrhizal association, the fungus colonizes the host plant's root tissues, either intracellularly as in arbuscular mycorrhizal fungi (AMF or AM), or extracellularly as in ectomycorrhizal fungi. The association is sometimes mutualistic. In particular species or in particular circumstances, mycorrhizae may have a parasitic association with host plants. Definition A mycorrhiza is a symbiotic association between a green plant and a fungus. The plant makes organic molecules such as sugars by photosynthesis and supplies them to the fungus, and the fungus supplies to the plant water and mineral nutrients, such as phosph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectomycorrhiza
An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobiont, and the roots of various plant species. The mycobiont is often from the phyla Basidiomycota and Ascomycota, and more rarely from the Zygomycota. Ectomycorrhizas form on the roots of around 2% of plant species, usually woody plants, including species from the birch, dipterocarp, myrtle, beech, willow, pine and rose families. Research on ectomycorrhizas is increasingly important in areas such as ecosystem management and restoration, forestry and agriculture. Unlike other mycorrhizal relationships, such as arbuscular mycorrhiza and ericoid mycorrhiza, ectomycorrhizal fungi do not penetrate their host's cell walls. Instead they form an entirely intercellular interface known as the Hartig net, consisting of highly branched hyphae form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectomycorrhiza
An ectomycorrhiza (from Greek ἐκτός ', "outside", μύκης ', "fungus", and ῥίζα ', "root"; pl. ectomycorrhizas or ectomycorrhizae, abbreviated EcM) is a form of symbiotic relationship that occurs between a fungal symbiont, or mycobiont, and the roots of various plant species. The mycobiont is often from the phyla Basidiomycota and Ascomycota, and more rarely from the Zygomycota. Ectomycorrhizas form on the roots of around 2% of plant species, usually woody plants, including species from the birch, dipterocarp, myrtle, beech, willow, pine and rose families. Research on ectomycorrhizas is increasingly important in areas such as ecosystem management and restoration, forestry and agriculture. Unlike other mycorrhizal relationships, such as arbuscular mycorrhiza and ericoid mycorrhiza, ectomycorrhizal fungi do not penetrate their host's cell walls. Instead they form an entirely intercellular interface known as the Hartig net, consisting of highly branched hyphae form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arbuscular Mycorrhizal Fungi
An arbuscular mycorrhiza (AM) (plural ''mycorrhizae'', a.k.a. ''endomycorrhiza'') is a type of mycorrhiza in which the symbiont fungus (''AM fungi'', or AMF) penetrates the cortical cells of the roots of a vascular plant forming arbuscules. (Not to be confused with ectomycorrhiza or ericoid mycorrhiza.) Arbuscular mycorrhizae are characterized by the formation of unique structures, arbuscules and vesicles, by Glomeromycota and Mucoromycota, sister clades of the more well-known and diverse dikaryan fungi (all three are together called "symbiomycota"). AM fungi help plants to capture nutrients such as phosphorus, sulfur, nitrogen and micronutrients from the soil. It is believed that the development of the arbuscular mycorrhizal symbiosis played a crucial role in the initial colonisation of land by plants and in the evolution of the vascular plants. It has been said that it is quicker to list the plants that do not form endomycorrhizae than those that do. This symbiosis is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arbuscular Mycorrhiza
An arbuscular mycorrhiza (AM) (plural ''mycorrhizae'', a.k.a. ''endomycorrhiza'') is a type of mycorrhiza in which the symbiont fungus (''AM fungi'', or AMF) penetrates the cortical cells of the roots of a vascular plant forming arbuscules. (Not to be confused with ectomycorrhiza or ericoid mycorrhiza.) Arbuscular mycorrhizae are characterized by the formation of unique structures, arbuscules and vesicles, by Glomeromycota and Mucoromycota, sister clades of the more well-known and diverse dikaryan fungi (all three are together called "symbiomycota"). AM fungi help plants to capture nutrients such as phosphorus, sulfur, nitrogen and micronutrients from the soil. It is believed that the development of the arbuscular mycorrhizal symbiosis played a crucial role in the initial colonisation of land by plants and in the evolution of the vascular plants. It has been said that it is quicker to list the plants that do not form endomycorrhizae than those that do. This symbiosis is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water. Function The major functions of roots are absorption of water, plant nutrition and anchoring of the plant body to the ground. Anatomy Root morphology is divided into four zones: the root cap, the apical meristem, the elongation zone, and the hair. The root cap of new roots helps the root penetrate the soil. These root caps are sloughed off as the root goes deeper creating a slimy surface that provides lubrication. The apical meristem behind the root cap produces new root cells that elongate. Then, root hairs form that absorb water and mineral nutrients from the soil. The first root in seed producing plants is the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutualism (biology)
Mutualism describes the ecological interaction between two or more species where each species has a net benefit. Mutualism is a common type of ecological interaction. Prominent examples include most vascular plants engaged in mutualistic interactions with mycorrhizae, flowering plants being pollinated by animals, vascular plants being dispersed by animals, and corals with zooxanthellae, among many others. Mutualism can be contrasted with interspecific competition, in which each species experiences ''reduced'' fitness, and exploitation, or parasitism, in which one species benefits at the expense of the other. The term ''mutualism'' was introduced by Pierre-Joseph van Beneden in his 1876 book ''Animal Parasites and Messmates'' to mean "mutual aid among species". Mutualism is often conflated with two other types of ecological phenomena: cooperation and symbiosis. Cooperation most commonly refers to increases in fitness through within-species (intraspecific) interactions, althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''true f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aglaophyton
''Aglaophyton major'' (or more correctly ''Aglaophyton majus'') was the sporophyte generation of a diplohaplontic, pre-vascular, axial, free-sporing land plant of the Lower Devonian (Pragian stage, around ). It had anatomical features intermediate between those of the bryophytes and vascular plants or tracheophytes. ''A. major'' was first described by Kidston and Lang in 1920 as the new species ''Rhynia major''. The species is known only from the Rhynie chert in Aberdeenshire, Scotland, where it grew in the vicinity of a silica-rich hot spring, together with a number of associated vascular plants such as a smaller species ''Rhynia gwynne-vaughanii'' which may be interpreted as a representative of the ancestors of modern vascular plants and '' Asteroxylon mackei'', which was an ancestor of modern clubmosses (Lycopsida). Description The stems of ''Aglaophyton'' were round in cross-section, smooth, unornamented, and up to about 6mm in diameter. Kidston and Lang interpreted the pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynie Chert
The Rhynie chert is a Lower Devonian sedimentary deposit exhibiting extraordinary fossil detail or completeness (a Lagerstätte). It is exposed near the village of Rhynie, Aberdeenshire, Scotland; a second unit, the Windyfield chert, is located some 700 m away. The Rhynie chert contains exceptionally preserved plant, fungus, lichen and animal material preserved in place by an overlying volcanic deposit. The bulk of the Devonian fossil bed consists of primitive plants (which had water-conducting cells and sporangia, but no true leaves), along with arthropods, lichens, algae and fungi. This fossil bed is remarkable for two reasons. First, the age of the site ( Pragian, Early Devonian, formed about ) places it at an early stage in the colonisation of land. Second, these cherts are famous for their exceptional state of ultrastructural preservation, with individual cell walls easily visible in polished specimens. Stomata have been counted and lignin remnants detected in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water – hence the name ''photosynthesis'', from the Greek ''phōs'' (), "light", and ''synthesis'' (), "putting together". Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll (and other colored) pigments/chromoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of Plant Evolution
This article attempts to place key plant innovations in a geological context. It concerns itself only with novel adaptations and events that had a major ecological significance, not those that are of solely anthropological interest. The timeline displays a graphical representation of the adaptations; the text attempts to explain the nature and robustness of the evidence. Plant evolution is an aspect of the study of biological evolution, predominantly involving evolution of plants suited to live on land, greening of various land masses by the filling of their niches with land plants, and diversification of groups of land plants. Earliest plants In the strictest sense, the name ''plant'' refers to those land plants that form the clade Embryophyta, comprising the bryophytes and vascular plants. However, the clade Viridiplantae or green plants includes some other groups of photosynthetic eukaryotes, including green algae. It is widely believed that land plants evolved from a group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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