Record ID No. |
1807 |
Author(s) |
Bolliger, A., Nalla, A., Magid, J., deNeergaard, A., Nalla, A.D., BogHansen, T.C , 2008 |
Affiliation |
Univ Copenhagen, Fac Life Sci, Dept Agr Sci, Plant & Soil Sci Lab, Thorvaldsensvej 40, DK-1871 Frederiksberg C, DENMARK |
Title |
Re-examining the glomalin-purity of glomalin-related soil protein fractions through immunochemical, lectin-affinity and soil labelling experiments |
Source. Vol.(no):Page |
Soil Biology & Biochemistry.40(4):887-893p. |
Categories |
Mycorrhiza General |
Subjects |
Biochemistry |
Sub-subjects |
Miscellaneous |
Organism |
n.a. |
Country |
DENMARK, Europe |
Abstracts |
Due to analytical similarities with the mycorrhizal glycoprotein glomalin,
ubiquitous citrate and heat-extractable soil protein fractions have been assumed to be
predominantly glomalin-stabilised within soil. Often termed glomalin-related soil protein (GRSP),
little however is actually known of the ''glomalin-purity'' of these soil fractions. We undertook
western and lectin blots and crossed immuno/lectin affinity electrophoresis (CIE/CLAE) analysis
of ''easily extractible'' GRSP fractions, as well as liquid chromatography-tandem mass
spectrometry (LC-MS/MS) of ''total'' GRSP fractions. To further test whether soil saprobes
contribute to GRSP production, we amended soil with C-14-sucrose and examined whether C-14 could
be traced in the GRSP pool over a 500-day incubation period. While only four of six bands on
SDS-PAGE profiles of easily extracted GRSP reacted with anti-glomalin MAb32B11 and the lectin Con
A under Our blotting conditions, CIE/CLAE indicated the presence of a single protein moiety in
the easily extractible GRSP pool. LC-MS/MS analysis of total GRSP pooled from various soils also
showed that although traces of protein tentatively assignable to soil bacteria were present in
GRSP, their concentrations were low. Additionally, specific activity of total GRSP in
C-14-labelled soil was relatively depleted compared to the bulk soil and soil microbial biomass.
This suggests that little GRSP of heterotrophic origin was laid down over the incubation period,
although the potential presence of a pre-existing C-14-free GRSP background, as well as of low
microbial dynamics in the absence of any further substrate inputs to the soil warrant caution
with this inference. (C) 2007 Elsevier Ltd. All rights reserved. |