the effect of iron limitation on the transcriptome and proteome of pseudomonas fluorescens pf-5铁的影响限制的转录组和蛋白质组荧光假pf-5.pdfVIP

The Effect of Iron Limitation on the Transcriptome and Proteome of Pseudomonas fluorescens Pf-5 1 1 1 2 1 Chee Kent Lim , Karl A. Hassan , Sasha G. Tetu , Joyce E. Loper , Ian T. Paulsen * 1 Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, Australia, 2 USDA-ARS Horticultural Crops Research Laboratory and Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America Abstract One of the most important micronutrients for bacterial growth is iron, whose bioavailability in soil is limited. Consequently, rhizospheric bacteria such as Pseudomonas fluorescens employ a range of mechanisms to acquire or compete for iron. We investigated the transcriptomic and proteomic effects of iron limitation on P. fluorescens Pf-5 by employing microarray and iTRAQ techniques, respectively. Analysis of this data revealed that genes encoding functions related to iron homeostasis, including pyoverdine and enantio-pyochelin biosynthesis, a number of TonB-dependent receptor systems, as well as some inner-membrane transporters, were significantly up-regulated in response to iron limitation. Transcription of a ribosomal protein L36-encoding gene was also highly up-regulated during iron limitation. Certain genes or proteins involved in biosynthesis of secondary metabolites such as 2,4-diacetylphloroglucinol (DAPG), orfamide A and pyrrolnitrin, as well as a chitinase, were over-expressed under iron-limited conditions. In contrast, we observed that expression of genes involved in hydrogen cyanide production and flagellar biosynthesis were down-regulated in an iron-depleted culture medium. Phenotypic tests revealed that Pf-5 had reduced swarming motility on