Glyceollins are a family of prenylated pterocarpans found in ineffective types of nodule in soybean in response to symbiotic infection. [1]
It possesses two chiral centers and can be asymmetrically synthesized chemically at a gram level scale. [2]
Molecules found in the family are :
They are phytoalexins [3] with an antiestrogenic activity. [4] Lygin et al. 2013 [5] finds antifungal activity against Phytophthora sojae and Macrophomina phaseolina , and Kim et al. 2010 against Aspergillus sojae . [3] Kaplan et al. 1980 finds nematicidal activity against Meloidogyne incognita . [3] Parniske et al. 1991 finds an antibacterial effect. [3] Glyceollin is a vital part of soybean immunity. [3]
Lygin et al. 2013 [5] find that daidzein is a precursor. [3] Glyceollin is a product of the phenylpropanoid pathway. [3] Glycinol is the direct precursor of glyceollins through the action of a prenyltransferase. Glyceollin synthase then transforms those prenylated precursors into glyceollins.
Some pathogens produce inhibitors. [3] Ziegler & Pontzen 1982 find Phytophthora megasperma produces an extracellular invertase, a mannanglycoprotein (a glycoprotein of mannan), which prevents glyceollin accumulation not by its enzymatic action but due to an effect of its carbohydrate moiety. [3]
Plant pathology is the scientific study of diseases in plants caused by pathogens and environmental conditions. Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. Not included are ectoparasites like insects, mites, vertebrate, or other pests that affect plant health by eating plant tissues. Plant pathology also involves the study of pathogen identification, disease etiology, disease cycles, economic impact, plant disease epidemiology, plant disease resistance, how plant diseases affect humans and animals, pathosystem genetics, and management of plant diseases.
Phytophthora infestans is an oomycete or water mold, a fungus-like microorganism that causes the serious potato and tomato disease known as late blight or potato blight. Early blight, caused by Alternaria solani, is also often called "potato blight". Late blight was a major culprit in the 1840s European, the 1845–1852 Irish, and the 1846 Highland potato famines. The organism can also infect some other members of the Solanaceae. The pathogen is favored by moist, cool environments: sporulation is optimal at 12–18 °C (54–64 °F) in water-saturated or nearly saturated environments, and zoospore production is favored at temperatures below 15 °C (59 °F). Lesion growth rates are typically optimal at a slightly warmer temperature range of 20 to 24 °C.
Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen. In general, they are gram negative, motile, non-sporulating rods.
Phytophthora is a genus of plant-damaging oomycetes, whose member species are capable of causing enormous economic losses on crops worldwide, as well as environmental damage in natural ecosystems. As well as impacting large scale agriculture, Phytophthora is a nuisance to garden and indoor plant hobbyists as well as bonsai artists. The cell wall of Phytophthora is made up of cellulose. The genus was first described by Heinrich Anton de Bary in 1875. Approximately 170 species have been described, although 100–500 undiscovered Phytophthora species are estimated to exist.
Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. Chemicals used to control oomycetes, which are not fungi, are also referred to as fungicides, as oomycetes use the same mechanisms as fungi to infect plants. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upwardly.
Phytoalexins are antimicrobial substances, some of which are antioxidative as well. They are defined, not by their having any particular chemical structure or character, but by the fact that they are defensively synthesized de novo by plants that produce the compounds rapidly at sites of pathogen infection. In general phytoalexins are broad spectrum inhibitors; they are chemically diverse, and different chemical classes of compounds are characteristic of particular plant taxa. Phytoalexins tend to fall into several chemical classes, including terpenoids, glycosteroids and alkaloids, however the term applies to any phytochemicals that are induced by microbial infection.
Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia. This process has evolved multiple times within the legumes, as well as in other species found within the Rosid clade. Legume crops include beans, peas, and soybeans.
Daidzein is a naturally occurring compound found exclusively in soybeans and other legumes and structurally belongs to a class of compounds known as isoflavones. Daidzein and other isoflavones are produced in plants through the phenylpropanoid pathway of secondary metabolism and are used as signal carriers, and defense responses to pathogenic attacks. In humans, recent research has shown the viability of using daidzein in medicine for menopausal relief, osteoporosis, blood cholesterol, and lowering the risk of some hormone-related cancers, and heart disease. Despite the known health benefits, the use of both puerarin and daidzein is limited by their poor bioavailability and low water solubility.
Phytophthora sojae is an oomycete and a soil-borne plant pathogen that causes stem and root rot of soybean. This is a prevalent disease in most soybean growing regions, and a major cause of crop loss. In wet conditions the pathogen produces zoospores that move in water and are attracted to soybean roots. Zoospores can attach to roots, germinate, and infect the plant tissues. Diseased roots develop lesions that may spread up the stem and eventually kill the entire plant. Phytophthora sojae also produces oospores that can remain dormant in the soil over the winter, or longer, and germinate when conditions are favourable. Oospores may also be spread by animals or machinery.
Macrophomina phaseolina is a Botryosphaeriaceae plant pathogen fungus that causes damping off, seedling blight, collar rot, stem rot, charcoal rot, basal stem rot, and root rot on many plant species.
Robert B. Mellor is a British scientist probably best known for his 1989 "unified vacuole theory", although also made significant contributions to environmental technology and to our understanding of the workings of the tech entrepreneurship ecosystem.
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Pterocarpans are derivatives of isoflavonoids found in the family Fabaceae. It is a group of compounds which can be described as benzo-pyrano-furano-benzenes which can be formed by coupling of the B ring to the 4-one position.
Glyceollin I is a glyceollin, a type of prenylated pterocarpan. It is a phytoalexin found in the soybean.
Glyceollin III is a glyceollin, a type of pterocarpan, found in the soybean. It has an antiestrogenic effect. In soil, it has an antifungal activity against Aspergillus sojae.
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Noel Thomas Keen was an American plant physiologist. He spent his career teaching at University of California, Riverside (UCR). His research focused on the varied ability of cultivars to detect and resist pathogens.
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