Siderophores in plant root tissue: Tagetes patula nana colonized by the arbuscular mycorrhizal fungus Gigaspora margarita.

More than 70% of vascular plant species live in symbiosis with arbuscular mycorrhizal (AM) fungi. In addition to other effects this symbiosis is known for its significance for plant nutrition including iron. Fungal iron mobilization from soil is commonly dependent on siderophores.

The fate of siderophores: antagonistic environmental interactions in exudate-mediated micronutrient uptake.

Organisms acquire metals from the environment by releasing small molecules that solubilize and promote their specific uptake. The best known example of this nutrient uptake strategy is the exudation of siderophores, which are a structurally-diverse class of molecules that are traditionally viewed as being integral to iron uptake. Siderophores have been proposed to act through a variety of processes, but their effectiveness can be mitigated by a variety of chemical and physical processes of both biotic and abiotic origin.

Linear fusigen as the major hydroxamate siderophore of the ectomycorrhizal Basidiomycota Laccaria laccata and Laccaria bicolor.

A screening for siderophores produced by the ectomycorrhizal fungi Laccaria laccata and Laccaria bicolor in synthetic low iron medium revealed the release of several different hydroxamate siderophores of which four major siderophores could be identified by high resolution mass spectrometry. While ferricrocin, coprogen and triacetylfusarinine C were assigned as well as other known fungal siderophores, a major peak of the siderophore mixture revealed an average molecular mass of 797 for the iron-loaded compound. High resolution mass spectrometry indicated an absolute mass of m/z = 798.

Fe(III)-complexes of the tripodal trishydroxamate siderophore basidiochrome: potential biological implications.

One method of mobilization of iron by mycorrhizal organisms is through the secretion of small organic chelators called siderophores. Hydroxamate donor chelators are a common type of siderophore that is frequently used by fungal organisms. The primary siderophore that is produced by fungi from the genera Ceratobasidium and Rhizoctonia is the tripodal trishydroxamate siderophore basidiochrome.

Hydroxamate siderophores of the ectomycorrhizal fungi Suillus granulatus and S. luteus.

Despite indications that S. granulatus and S. luteus release iron-chelating compounds, the exact spectrum of ferric hydroxamates synthesized by these two Suillus species remained unclear.