Azoxystrobin
Encyclopedia
Azoxystrobin is a fungicide
Fungicide
Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. 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...

 commonly used in agriculture. The substance is used as an active agent protecting plants and fruit/vegetables from fungal diseases.

Origin

Azoxystrobin was discovered during research on Oudemansiella
Oudemansiella
Oudemansiella is a genus of fungi in the Physalacriaceae family. According to the Dictionary of the Fungi, the genus contains about 15 species that are widely distributed in tropical and temperate regions. Yang and colleagues revised the genus in a 2009 publication, describing several new species...

 mucida
and Strobilurus
Strobilurus
Strobilurus is a genus of fungi in the Physalacriaceae family. The genus has a widespread distribution in temperate regions, and contains 10 species. Species of Strobilurus grow on pine cones.-Species:*S. albipilatus*S. conigenoides...

 tenacellus
, which are small white or brown coloured mushrooms commonly found in the Czech forests. Not bigger than a few centimeters, these mushrooms attracted attention of scientists because of their remarkable ability to defend themselves. Their defense mechanism is based on the secretion of two substances, strobilurin A and oudemansin A. These substances allow them to keep their competitors at a distance and even destroy them when in range. Observations of this mechanism led directly to research that resulted in azoxystrobin.

Activity

After synthesizing experimental analogs of both substances (over 1400 were tested), azoxystrobin was found to be the most active and stable combination. The pharmacophore
Pharmacophore
thumb|right|300px|An example of a pharmacophore model.A pharmacophore is an abstract description of molecular features which are necessary for molecular recognition of a ligand by a biological macromolecule....

 of azoxystrobine is the β-methoxyacrylate portion, which is present in the active compounds from both Oudemansiella mucida and Strobilurus tenacellus. Azoxystrobin binds very tightly to the Qo site of Complex III of the mitochondrial electron transport chain, thereby ultimately preventing the generation of ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

.

Efficacy

Azoxystrobin possesses the broadest spectrum of activity of all presently known antifungals. It is presently the only counteragent that has the ability to protect against the 4 big groups of fungal diseases:
  • Ascomycota
    Ascomycota
    The Ascomycota are a Division/Phylum of the kingdom Fungi, and subkingdom Dikarya. Its members are commonly known as the Sac fungi. They are the largest phylum of Fungi, with over 64,000 species...

    : Septoria
  • Deuteromycota: Pyricularia (rice harvesting)
  • Basidiomycota
    Basidiomycota
    Basidiomycota is one of two large phyla that, together with the Ascomycota, comprise the subkingdom Dikarya within the Kingdom Fungi...

    : Stripe rust
  • Oomycota: Water mould (grape harvesting)

Examples

Azoxystrobin is widely used in farming, particularly in wheat farming. Applying agents containing azoxystrobin provides protection against many types of diseases, including:
  • Wheat septoria
  • Septoria leaf spot
  • Wheat leaf rust
    Wheat leaf rust
    Wheat leaf rust, is fungal disease that effects wheat, barley and rye stems, leaves and grains. In temperate zones it is destructive on winter wheat because the pathogen overwinters. Infections can lead up to 20% yield loss - exacerbated by dying leaves which fertilize the fungus. The pathogen is...

     (Puccinia recondita)
  • Rye leafrust (Puccinia triticina)
  • Powdery mildew
    Powdery mildew
    Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales. It is one of the easier diseases to spot, as its symptoms are quite distinctive. Infected plants display white powdery spots on the...

  • Downy mildew
    Downy mildew
    Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants. Downy mildews exclusively belong to Peronosporaceae. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vegetables that grow on vines...

  • Stripe rust
  • Haustorium
    Haustorium
    In botany, a haustorium is the appendage or portion of a parasitic fungus or of the root of a parasitic plant that penetrates the host's tissue and draws nutrients from it. Haustoria do not penetrate the host's cell membranes.Fungi in all major divisions form haustoria...

  • Pyrenophora teres
    Pyrenophora teres
    Pyrenophora teres is a necrotrophic fungal pathogen of some plant species, the most significant of which are economically important agricultural crops such as barley.- Dispersal and spread :...


Ecotoxicology

Azoxystrobin has a favorable ecotoxicological
Ecotoxicology
Ecotoxicology is the study of the effects of toxic chemicals on biological organisms, especially at the population, community, ecosystem level. Ecotoxicology is a multidisciplinary field, which integrates toxicology and ecology....

 profile, meeting the expectations of agricultural demand.

Its toxicity is low for mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s, bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s, bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...

s, insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s, and earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...

s. It is highly toxic for freshwater fish and invertebraes and very highly toxic for marine invertebraes. (this is disputed. Please read discussion page for details)

Azoxystrobin is broken down into the soil. The agent is not very mobile and therefore is unlikely to penetrate further in the soil and come into contact with groundwater.

External links

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