title: Mutational, proteomic and metabolomic analysis of a plant growth promoting copper-resistant Pseudomonas spp.
abstract: Pseudomonas sp. TLC6-6.5-4 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 (Tn5) mutants. Two copper-sensitive mutants with significant reduction in copper resistance were identified: CSM1, a mutant disrupted in trpA gene (tryptophan synthase alpha subunit), and CSM2, a mutant disrupted in clpA gene (ATP-dependent Clp protease). Proteomic and metabolomic analyses were performed to identify biochemical and molecular mechanisms involved in copper resistance using CSM2 due to its lower minimum inhibitory concentration compared with CSM1 and the wild type. Proteomic analysis revealed that disruption of Clp 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.
authors: Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA.
authors: Kefeng
authors: K
authors: Li
authors: Ramana R
authors: RR
authors: Pidatala
authors: Wusirika
authors: W
authors: Ramakrishna
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000704:Analysis of Variance; D001426:Bacterial Proteins / Q000032:analysis / Q000145:classification / Q000378:metabolism; D048430:Cell Shape / Q000187:drug effects; D016000:Cluster Analysis; D003300:Copper / Q000633:toxicity*; D004252:DNA Mutational Analysis; D049071:Endopeptidase Clp / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D055442:Metabolome / Q000187:drug effects; D055432:Metabolomics; D008954:Models, Biological; D009010:Monte Carlo Method; D063245:Plant Development; D020543:Proteome / Q000187:drug effects; D040901:Proteomics; D011549:Pseudomonas / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D013312:Stress, Physiological / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D020543:Proteome; D003300:Copper; D049071:Endopeptidase Clp