AUTHOR=Ohno Katie M. , Bishell Amy B. , Stanosz Glen R. 

TITLE=Gene Expression Analysis of Three Putative Copper-Transporting ATPases in Copper-Tolerant Fibroporia radiculosa

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.586940

DOI=10.3389/fmicb.2020.586940

ISSN=1664-302X

ABSTRACT=<p>Copper tolerance of brown-rot basidiomycete decay fungi can lessen the efficacy of copper-containing wood preservatives for wood products in-service. The purpose of this study was to evaluate wood mass loss and differential expression of three genes that have putative annotations for copper-transporting ATPase pumps (FIBRA_00974, FIBRA_04716, and FIBRA_01430). Untreated southern pine (SP) and SP treated with three concentrations of ammoniacal copper citrate (CC, 0.6, 1.2, and 2.4%) were exposed to two copper-tolerant <italic>Fibroporia radiculosa</italic> isolates (FP-90848-T and L-9414-SP) and copper-sensitive <italic>Gloeophyllum trabeum</italic> isolate (MAD 617) in a 4-week-long standard decay test (AWPA E10-19). Decay of copper-treated wood was inhibited by <italic>G. trabeum</italic> (<italic>p</italic> = 0.001); however, there was no inhibition of decay with increasing copper concentrations by both <italic>F. radiculosa</italic> isolates. Initially, <italic>G. trabeum</italic> and one <italic>F. radiculosa</italic> isolate (L-9414-SP) highly upregulated FIBRA_00974 and FIBRA_04716 on copper-treated wood at week 1 (<italic>p</italic> = 0.005), but subsequent expression was either not detected or was similar to expression on untreated wood (<italic>p</italic> = 0.471). The other <italic>F. radiculosa</italic> isolate (FP-90848-T) downregulated FIBRA_00974 (<italic>p</italic> = 0.301) and FIBRA_04716 (<italic>p</italic> = 0.004) on copper-treated wood. FIBRA_01430 expression by <italic>G. trabeum</italic> was not detected, but was upregulated by both <italic>F. radiculosa</italic> FP-90848-T (<italic>p</italic> = 0.481) and L-9414-SP (<italic>p</italic> = 0.392). Results from this study suggest that all three test fungi utilized different mechanisms when decaying copper-treated wood. Additionally, results from this study do not provide support for the involvement of these putative gene annotations for copper-transporting ATPase pumps in the mechanism of copper-tolerance.</p>