Open AccessMutational, proteomic and metabolomic analysis of a plant growth promoting copper‐resistant P seudomonas spp.
Author(s) -
Li Kefeng,
Pidatala Ramana R,
Ramakrishna Wusirika
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2012.02646.x
Subject(s) - metabolomics , pseudomonas , copper , biology , microbiology and biotechnology , pseudomonas aeruginosa , bacteria , genetics , chemistry , bioinformatics , organic chemistry
P seudomonas sp. TLC 6‐6.5‐4 is a multiple metal resistant plant growth‐promoting bacteria isolated from copper‐contaminated lake sediments. In this study, a comprehensive analysis of genes involved in copper resistance was performed by generating a library of transposon ( T n5) mutants. Two copper‐sensitive mutants with significant reduction in copper resistance were identified: CSM 1, a mutant disrupted in trpA gene (tryptophan synthase alpha subunit), and CSM 2, a mutant disrupted in clpA gene ( ATP ‐dependent C lp protease). Proteomic and metabolomic analyses were performed to identify biochemical and molecular mechanisms involved in copper resistance using CSM 2 due to its lower minimum inhibitory concentration compared with CSM 1 and the wild type. Proteomic analysis revealed that disruption of C lp protease gene up‐regulated molecular chaperones and down‐regulated the expression of enzymes related to tRNA modification, whereas metabolomic analysis showed that amino acid and oligosaccharide transporters that are part of ATP‐binding cassette (ABC) transporters pathways were down‐regulated. Further, copper stress altered metabolic pathways including the tricarboxylic acid cycle, protein absorption and glyoxylate metabolism.