Quorum sensing regulates exopolysaccharide production, motility, and virulence in Pseudomonas syringae
Quorum sensing regulates exopolysaccharide production, motility, and virulence in Pseudomonas syringae
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DOI：
10.1094/mpmi-18-0682
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发表时间：
2005-07-01
影响因子：
3.5
通讯作者：
Lindow, SE
中科院分区：
文献类型：
--
作者：
Quiñones, B;Dulla, G;Lindow, SE
研究了植物病原菌假单胞菌（Pseudomonaserichingae pv.）该菌需要阿勒合酶AhlI和调节剂AhIR，并且另外受到AefR的调节。研究了群体感应对各种预期参与附生适合度和毒力的性状表达的贡献。与野生型菌株相比，阿勒生产缺陷的aefR（-）突变体和ahlI（-）ahlR（-）双突变体在藻酸盐生产中显著受损，并且对过氧化氢的敏感性增加。这些突变体是hypermotile在文化中，更迅速地侵入叶片，并造成了48小时的潮湿孵育后，豆叶片上的褐斑病变的发病率增加。有趣的是，aefR（-）突变体是最活跃的和致命的。与野生型菌株一样，AHL缺陷突变株在豆荚上引起水浸损伤。然而，由ahlI（-）ahlR（-）双突变体引起的病变较大，而由aefR（-）突变体引起的病变较小。与此相反，豆荚的组织浸渍，这发生在感染的后期阶段，在AHL缺陷型突变体中被完全废除。在发病率和植物生长的P. erichingae pv。与野生型植物相比，在产生阿勒的转基因烟草植物中，烟粉虱的数量大大减少。这些结果表明，群体感应在P. pastingae调节性状，有助于附生健身以及不同阶段的疾病发展过程中的植物感染。
The N-acyl homoserine lactone (AHL)-mediated quorum-sensing system in the phytopathogen Pseudomonas syringae pv. syringae requires the AHL synthase AhlI and the regulator AhIR, and is additionally subject to regulation by AefR. The contribution of quorum sensing to the expression of a variety of traits expected to be involved in epiphytic fitness and virulence of P. syringae were examined. Both an aefR(-) mutant and an ahlI(-) ahlR(-) double mutant, deficient in AHL production, were significantly impaired in alginate production and had an increased susceptibility to hydrogen peroxide compared with the wild-type strain. These mutants were hypermotile in culture, invaded leaves more rapidly, and caused an increased incidence of brown spot lesions on bean leaves after a 48-h moist incubation. Interestingly, an aefR(-) mutant was both the most motile and virulent. Like the wild-type strain, the AHL-deficient mutant strains incited water-soaked lesions on bean pods. However, lesions caused by an ahlI(-) ahlR(-) double mutant were larger, whereas those incited by an aefR(-) mutant were smaller. In contrast, tissue maceration of pods, which occurs at a later stage of infection, was completely abolished in the AHL-deficient mutants. Both the incidence of disease and in planta growth of P. syringae pv. tabaci were greatly reduced in transgenic tobacco plants that produced AHL compared with wild-type plants. These results demonstrate that quorum sensing in P. syringae regulates traits that contribute to epiphytic fitness as well as to distinct stages of disease development during plant infection.