ARS | Publication request: MICROARRAY DETECTION OF GENES FOR LIGNIN-DEGRADING ENZYMES IN SOIL FUNGI

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: July 1, 2003
Publication Date: N/A

Technical Abstract: Lignin is a complex biopolymer that is degraded by fungi. Several extracellular enzymes have been implicated in degradation and include lignin peroxidases, laccases, manganese peroxidases, and glyoxal oxidases. Versions of these enzymes are produced by multiple species of fungi, and in some cases, multiple versions of a single enzyme may be produced by the same species of fungus. Previous research has indicated changes in fungal activity and diversity along a tallgrass prairie restoration chronosequence (Fermi National Lab, IL). A cDNA microarray was designed to interrogate the expression and microbial source of these lignin degrading enzymes in the chronosequence soils. We hypothesized that less diversity in gene expression would be detected in a farmed soil than in a restored prairie soil. Previous research has indicated significantly more fungal activity and biomass in the restored prairie soil than in the farmed soil. The array had 46 oligonucleotides (15-25mer) that represent each of the enzymes listed above. Messenger RNA was extracted from 32 one-gram subsamples of the target soils, then all of the extracts were pooled prior to RNA precipitation and mRNA purification. Aminoallyl modified dUTPs were incorporated during reverse transcription, after which the cDNA was labeled with Alexa-546 dye. The labeled cDNA was hybridized with the microarray for 24 hours and then imaged. Our results support the hypothesis that fewer genes were expressed in the farmed soil than in the restored soil.