Institute of Environmentally-Friendly Agriculture, Chonnam National University, Gwangju 500-757, Korea.
Department of Biology, Utah State University, Logan, UT, USA.
Plant Pathol J. 2013 Sep;29(3):323-9. doi: 10.5423/PPJ.NT.01.2013.0013.
The stationary-phase sigma factor, RpoS, influences the expression of factors important in survival of Pseudomonas chlororaphis O6 in the rhizosphere. A partial proteomic profile of a rpoS mutant in P. chlororaphis O6 was conducted to identify proteins under RpoS regulation. Five of 14 differentially regulated proteins had unknown roles. Changes in levels of proteins in P. chlororaphis O6 rpoS mutant were associated with iron metabolism, and protection against oxidative stress. The P. chlororaphis O6 rpoS mutant showed increased production of a pyoverdine-like siderophore, indole acetic acid, and altered isozyme patterns for peroxidase, catalase and superoxide dismutase. Consequently, sensitivity to hydrogen peroxide exposure increased in the P. chlororaphis O6 rpoS mutant, compared with the wild type. Taken together, RpoS exerted regulatory control over factors important for the habitat of P. chlororaphis O6 in soil and on root surfaces. The properties of several of the proteins in the RpoS regulon are currently unknown.
固着期σ因子 RpoS 影响假单胞菌属叶绿素 O6 在根际中存活的重要因素的表达。对假单胞菌属叶绿素 O6 的 rpoS 突变体进行了部分蛋白质组学分析，以鉴定受 RpoS 调控的蛋白质。在 14 个差异调节蛋白中有 5 个具有未知作用。rpoS 突变体中假单胞菌属叶绿素 O6 蛋白水平的变化与铁代谢和抗氧化应激保护有关。与野生型相比，假单胞菌属叶绿素 O6 rpoS 突变体产生更多的类似于绿脓菌素的铁载体、吲哚乙酸，并改变过氧化物酶、过氧化氢酶和超氧化物歧化酶的同工酶模式。因此，rpoS 突变体对过氧化氢的敏感性增加。总之，RpoS 对假单胞菌属叶绿素 O6 在土壤和根表面的栖息地的重要因素进行了调节控制。RpoS 调控子中的几种蛋白质的特性目前尚不清楚。
