Importance of N -Acyl-Homoserine Lactone-Based Quorum Sensing and Quorum Quenching in Pathogen Control and Plant Growth Promotion

• Published in: Pathogens (Basel) Vol. 10; no. 12; p. 1561
• Main Authors: Hartmann, Anton, Klink, Sophia, Rothballer, Michael
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30.11.2021; MDPI
• Subjects: AI-2; Bacteria; Biofilms; Biological control; Biosynthesis; Chemical communication; Evolution; Fatty acids; Gene expression; Genes; Genomes; Gram-negative bacteria; Gram-positive bacteria; Homoserine lactones; Insects; Lactones; Metabolism; Metabolites; Microbiomes; Microorganisms; Mutation; N-Acyl homoserine lactone; N-acyl-homoserine lactones; Opinion; Optimization; Pathogens; Pest control; Plant growth; plant perception; Priming; quorum quenching; Quorum sensing; Receptors; Signaling; Virulence; field application; AI-2; quorum sensing; quorum quenching; biological control; N-acyl-homoserine lactones; plant perception
• ISSN: 2076-0817; 2076-0817
• DOI: 10.3390/pathogens10121561

The biological control of plant pathogens is linked to the composition and activity of the plant microbiome. Plant-associated microbiomes co-evolved with land plants, leading to plant holobionts with plant-beneficial microbes but also with plant pathogens. A diverse range of plant-beneficial microbes assists plants to reach their optimal development and growth under both abiotic and biotic stress conditions. Communication within the plant holobiont plays an important role, and besides plant hormonal interactions, quorum-sensing signalling of plant-associated microbes plays a central role. Quorum-sensing (QS) autoinducers, such as -acyl-homoserine lactones (AHL) of Gram-negative bacteria, cause a pronounced interkingdom signalling effect on plants, provoking priming processes of pathogen defence and insect pest control. However, plant pathogenic bacteria also use QS signalling to optimise their virulence; these QS activities can be controlled by quorum quenching (QQ) and quorum-sensing inhibition (QSI) approaches by accompanying microbes and also by plants. Plant growth-promoting bacteria (PGPB) have also been shown to demonstrate QQ activity. In addition, some PGPB only harbour genes for AHL receptors, so-called -solo genes, which can contribute to plant growth promotion and biological control. The presence of autoinducer solo receptors may reflect ongoing microevolution processes in microbe-plant interactions. Different aspects of QS systems in bacteria-plant interactions of plant-beneficial and pathogenic bacteria will be discussed, and practical applications of bacteria with AHL-producing or -quenching activity; QS signal molecules stimulating pathogen control and plant growth promotion will also be presented.