The arbuscular mycorrhizal fungal protein glomalin is a putative homolog of heat shock protein 60

Abstract

Work on glomalin-related soil protein produced by arbuscular mycorrhizal (AM) fungi (AMF) has been limited because of the unknown identity of the protein. A protein band cross-reactive with the glomalin-specific antibody MAb32B11 from the AM fungus Glomus intraradices was partially sequenced using tandem liquid chromatography-mass spectrometry. A 17 amino acid sequence showing similarity to heat shock protein 60 (hsp 60) was obtained. Based on degenerate PCR, a full-length cDNA of 1773 bp length encoding the hsp 60 gene was isolated from a G. intraradices cDNA library. The ORF was predicted to encode a protein of 590 amino acids. The protein sequence had three N-terminal glycosylation sites and a string of GGM motifs at the C-terminal end. The GiHsp 60 ORF had three introns of 67, 76 and 131 bp length. The GiHsp 60 was expressed using an in vitro translation system, and the protein was purified using the 6xHis-tag system. A dot-blot assay on the purified protein showed that it was highly cross-reactive with the glomalin-specific antibody MAb32B11. The present work provides the first evidence for the identity of the glomalin protein in the model AMF G. intraradices, thus facilitating further characterization of this protein, which is of great interest in soil ecology.

Contribution of inoculation with arbuscular mycorrhizal fungi to the bioremediation of a copper polluted soil using Oenothera picensis

“…Previous studies have shown that glomalin, a glycoprotein produced by AM fungi (Wright et al, 1996;Gadkar and Rillig, 2006;Rillig and Mummey, 2006), can binds metals, including Cu (González-Chávez et al, 2004;Cornejo et al, 2008;Meier et al, 2012c). This glycoprotein is distinguished by its extraction and detection methods (Wright et al, 1996;2006;Wright and Upadhyaya, 1998;Purin and Rillig, 2007) and has been quantified as a Bradford-reactive soil protein (BRSP; Rillig, 2004).…”

Untangling the biological contributions to soil stability in semiarid shrublands

“…These fungi deliver a variety of benefits to plants (e.g., increased nutrient uptake, improved water relations, protection from pathogens) in exchange for photosynthates (Newsham et al 1995). Arbuscular mycorrhizal fungi have been found to physically stabilize soil through the enmeshment of soil particles by filamentous hyphal networks and the production of glomalin, a putative heat-shock protein homolog (Gadkar and Rillig 2006), quantified in soils as operationally defined glomalin-related soil protein (GRSP; Wright and Upadhyaya 1996, Miller and Jastrow 2000, Rillig 2004. Glomalin is a component of the hyphal walls of AM fungi, which likely remains recalcitrant in soils following hyphal decomposition (Driver et al 2005, Gadkar andRillig 2006).…”

“…Arbuscular mycorrhizal fungi have been found to physically stabilize soil through the enmeshment of soil particles by filamentous hyphal networks and the production of glomalin, a putative heat-shock protein homolog (Gadkar and Rillig 2006), quantified in soils as operationally defined glomalin-related soil protein (GRSP; Wright and Upadhyaya 1996, Miller and Jastrow 2000, Rillig 2004. Glomalin is a component of the hyphal walls of AM fungi, which likely remains recalcitrant in soils following hyphal decomposition (Driver et al 2005, Gadkar andRillig 2006). Both hyphal density and GRSP concentration in soils have been found to be strongly correlated with aggregate stability in mesic soils (Wright and Upadhyaya 1998).…”

Development of Preparative Chromatography for Proteomic Approach of Mycorrhizal Symbiosis

“…These results suggest that the proteins will be glomalin-like proteins which relieve cells from stresses. Glomalin has been already known as glycoprotein weighs approximately 60 kDa [9], which has similarity to heat shock protein 60 [10].…”