Blanco-Romero Esther, Durán David, Garrido-Sanz Daniel, Redondo-Nieto Miguel, Martín Marta, Rivilla Rafael
Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049 Madrid, Spain.
Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland.
Microorganisms. 2023 Apr 15;11(4):1037. doi: 10.3390/microorganisms11041037.
Motility and biofilm formation are two crucial traits in the process of rhizosphere colonization by pseudomonads. The regulation of both traits requires a complex signaling network that is coordinated by the AmrZ-FleQ hub. In this review, we describe the role of this hub in the adaption to the rhizosphere. The study of the direct regulon of AmrZ and the phenotypic analyses of an mutant in F113 has shown that this protein plays a crucial role in the regulation of several cellular functions, including motility, biofilm formation, iron homeostasis, and bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, controlling the synthesis of extracellular matrix components. On the other hand, FleQ is the master regulator of flagellar synthesis in . F113 and other pseudomonads, but its implication in the regulation of multiple traits related with environmental adaption has been shown. Genomic scale studies (ChIP-Seq and RNA-Seq) have shown that in F113, AmrZ and FleQ are general transcription factors that regulate multiple traits. It has also been shown that there is a common regulon shared by the two transcription factors. Moreover, these studies have shown that AmrZ and FleQ form a regulatory hub that inversely regulate traits such as motility, extracellular matrix component production, and iron homeostasis. The messenger molecule c-di-GMP plays an essential role in this hub since its production is regulated by AmrZ and it is sensed by FleQ and required for its regulatory role. This regulatory hub is functional both in culture and in the rhizosphere, indicating that the AmrZ-FleQ hub is a main player of F113 adaption to the rhizosphere environment.
运动性和生物膜形成是假单胞菌在根际定殖过程中的两个关键特性。这两个特性的调控需要一个由AmrZ-FleQ枢纽协调的复杂信号网络。在这篇综述中，我们描述了这个枢纽在适应根际环境中的作用。对AmrZ直接调控子的研究以及F113中一个突变体的表型分析表明，该蛋白在多种细胞功能的调控中起关键作用，包括运动性、生物膜形成、铁稳态以及双（3'-5'）-环二鸟苷单磷酸（c-di-GMP）周转，控制细胞外基质成分的合成。另一方面，FleQ是F113和其他假单胞菌中鞭毛合成的主要调节因子，但它在与环境适应相关的多种特性调控中的作用也已得到证实。基因组规模研究（ChIP-Seq和RNA-Seq）表明，在F113中，AmrZ和FleQ是调控多种特性的一般转录因子。研究还表明，这两个转录因子存在共同的调控子。此外，这些研究表明，AmrZ和FleQ形成一个调控枢纽，反向调控运动性、细胞外基质成分产生和铁稳态等特性。信使分子c-di-GMP在这个枢纽中起重要作用，因为它的产生受AmrZ调控，被FleQ感知并对其调控作用是必需的。这个调控枢纽在培养物和根际中均有功能，表明AmrZ-FleQ枢纽是F113适应根际环境的主要参与者。
