Quorum sensing coordinates brute force and stealth modes of infection in the plant pathogen Pectobacterium atrosepticum.
Quorum sensing coordinates brute force and stealth modes of infection in the plant pathogen Pectobacterium atrosepticum.
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DOI：
10.1371/journal.ppat.1000093
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发表时间：
2008-06-20
期刊：
影响因子：
6.7
通讯作者：
Toth, Ian K.
中科院分区：
文献类型：
--
作者：
Liu, Hui;Coulthurst, Sarah J.;Pritchard, Leighton;Hedley, Peter E.;Ravensdale, Michael;Humphris, Sonia;Burr, Tom;Takle, Gunnhild;Brurberg, May-Bente;Birch, Paul R. J.;Salmond, George P. C.;Toth, Ian K.
群体感应（QS）在体外控制生产的植物细胞壁降解酶（PCWDE）和其他毒力因子的软腐肠细菌的植物病原体Pectobacterium atrosepticum（Pba）。在这里，我们证明了基因组范围内的调节作用的QS在体内的铅-马铃薯的相互作用，使用铅特异性微阵列。我们发现，26%的Pba基因组表现出不同的转录在QS（expI-）突变体，与野生型相比，这表明QS可能作出更大的贡献，发病机制比以前认为的。我们鉴定了QS调节子的新组分，包括参与PCWDE分泌的I型和II型分泌系统、新型VI型分泌系统（T6 SS）及其预测的底物Hcp和VgrG;超过70种已知或推定的调节剂，其中一些已被证明控制发病机制，值得注意的是，III型分泌系统和相关的效应蛋白，和coronafacoyl-酰胺共轭物，两者都在操纵植物防御中起作用。我们表明，T6 SS和一种新的潜在的调节器，VirS，需要在Pba的完整的毒力，并提出了一个模型，将QS在控制Pba的疾病进展的后期阶段的监管层次的顶点。我们的研究结果表明，QS是一个主调节植物病原体，控制多个其他监管机构，反过来，协调调节基因与操纵主机防御音乐会的破坏性武器库的PCWDEs，表现出软腐病表型。许多革兰氏阴性菌使用称为群体感应（QS）的群体密度依赖性调节机制来控制感染期间毒力因子的产生。在细菌性植物病原体黑腐果胶杆菌（Pectobacterium atrosepticum）（以前的胡萝卜软腐欧文氏菌（Erwinia carotovora subsp. atroseptica）是QS的重要模型，该机制调节物理攻击宿主植物细胞壁的酶的产生。本研究利用全基因组芯片技术研究了植物感染过程中QS调节子的表达。结果表明，QS调节一组更广泛的基本毒力因子比以前认识到的。这些包括与以前未与QS相关的其他植物和动物病原体中的毒力因子相似的毒力因子，例如，第六型分泌系统（及其潜在的底物），首次被证明是植物病原体毒力所必需的;和植物毒素冠状酸，已知在其他病原体中发挥作用，操纵植物防御。这项研究提供了第一个证据，果胶杆菌可能会针对宿主防御的同时，对植物细胞壁的物理攻击。此外，该研究表明，广泛的先前已知和未知的毒力调节因子位于QS调节子内，揭示了它是毒力的主要调节因子。
Quorum sensing (QS) in vitro controls production of plant cell wall degrading enzymes (PCWDEs) and other virulence factors in the soft rotting enterobacterial plant pathogen Pectobacterium atrosepticum (Pba). Here, we demonstrate the genome-wide regulatory role of QS in vivo during the Pba–potato interaction, using a Pba-specific microarray. We show that 26% of the Pba genome exhibited differential transcription in a QS (expI-) mutant, compared to the wild-type, suggesting that QS may make a greater contribution to pathogenesis than previously thought. We identify novel components of the QS regulon, including the Type I and II secretion systems, which are involved in the secretion of PCWDEs; a novel Type VI secretion system (T6SS) and its predicted substrates Hcp and VgrG; more than 70 known or putative regulators, some of which have been demonstrated to control pathogenesis and, remarkably, the Type III secretion system and associated effector proteins, and coronafacoyl-amide conjugates, both of which play roles in the manipulation of plant defences. We show that the T6SS and a novel potential regulator, VirS, are required for full virulence in Pba, and propose a model placing QS at the apex of a regulatory hierarchy controlling the later stages of disease progression in Pba. Our findings indicate that QS is a master regulator of phytopathogenesis, controlling multiple other regulators that, in turn, co-ordinately regulate genes associated with manipulation of host defences in concert with the destructive arsenal of PCWDEs that manifest the soft rot disease phenotype. Many Gram-negative bacteria use a population density-dependent regulatory mechanism called quorum sensing (QS) to control the production of virulence factors during infection. In the bacterial plant pathogen Pectobacterium atrosepticum (formerly Erwinia carotovora subsp. atroseptica), an important model for QS, this mechanism regulates production of enzymes that physically attack the host plant cell wall. This study used a whole genome microarray-based approach to investigate the entire QS regulon during plant infection. Results demonstrate that QS regulates a much wider set of essential virulence factors than was previously appreciated. These include virulence factors similar to those in other plant and animal pathogens that have not previously been associated with QS, e.g., a Type VI secretion system (and its potential substrates), shown for the first time to be required for virulence in a plant pathogen; and the plant toxin coronafacic acid, known in other pathogens to play a role in manipulating plant defences. This study provides the first evidence that Pectobacterium may target host defences simultaneously with a physical attack on the plant cell wall. Moreover, the study demonstrates that a wide range of previously known and unknown virulence regulators lie within the QS regulon, revealing it to be the master regulator of virulence.
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DOI：
10.1073/pnas.81.13.4154
发表时间：
1984-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
ENGEBRECHT, J;SILVERMAN, M
通讯作者：
SILVERMAN, M
影响因子：
3.2
作者：
Bleves, S;Soscia, C;Filloux, A
通讯作者：
Filloux, A
影响因子：
3.6
作者：
Burr, T;Barnard, AML;Salmond, GPC
通讯作者：
Salmond, GPC
影响因子：
3.2
作者：
Cui, YY;Chatterjee, A;Chatterjee, AK
通讯作者：
Chatterjee, AK
影响因子：
3.6
作者：
McGowan, SJ;Barnard, AML;Salmond, GPC
通讯作者：
Salmond, GPC