Bacterial type VI secretion systems (T6SSs) are molecular weapons designed to deliver toxic effectors into prey cells. These nanomachines have an important role in inter-bacterial competition and provide advantages to T6SS active strains in polymicrobial environments. Here we analyze the genome of the biocontrol agent Pseudomonas putida KT2440 and identify three T6SS gene clusters (K1-, K2- and K3-T6SS). Besides, 10 T6SS effector\uffe2\uff80\uff93immunity pairs were found, including putative nucleases and pore-forming colicins. We show that the K1-T6SS is a potent antibacterial device, which secretes a toxic Rhs-type effector Tke2. Remarkably, P. putida eradicates a broad range of bacteria in a K1-T6SS-dependent manner, including resilient phytopathogens, which demonstrates that the T6SS is instrumental to empower P. putida to fight against competitors. Furthermore, we observed a drastically reduced necrosis on the leaves of Nicotiana benthamiana during co-infection with P. putida and Xanthomonas campestris. Such protection is dependent on the activity of the P. putida T6SS. Many routes have been explored to develop biocontrol agents capable of manipulating the microbial composition of the rhizosphere and phyllosphere. Here we unveil a novel mechanism for plant biocontrol, which needs to be considered for the selection of plant wardens whose mission is to prevent phytopathogen infections.
", "keywords": ["PROTEIN SECRETION", "Nicotiana", "0301 basic medicine", "570", "INTESTINAL INFLAMMATION", "05 Environmental Sciences", "VIBRIO-CHOLERAE", "Environmental Sciences & Ecology", "VI SECRETION SYSTEM", "Xanthomonas campestris", "Microbiology", "03 medical and health sciences", "Bacterial Proteins", "10 Technology", "Plant Diseases", "0303 health sciences", "Science & Technology", "Ecology", "Pseudomonas putida", "ROOT MICROBIOME", "Gene Expression Regulation", " Bacterial", "06 Biological Sciences", "Type VI Secretion Systems", "GENOMIC ANALYSIS", "Biological Control Agents", "ESCHERICHIA-COLI", "EFFECTORS", "IMMUNITY PROTEINS", "Original Article", "HOST-RANGE", "Life Sciences & Biomedicine"]}, "links": [{"href": "http://www.nature.com/articles/ismej2016169.pdf"}, {"href": "https://doi.org/10.1038/ismej.2016.169"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/The%20ISME%20Journal", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1038/ismej.2016.169", "name": "item", "description": "10.1038/ismej.2016.169", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1038/ismej.2016.169"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-01-03T00:00:00Z"}}, {"id": "10.1111/1462-2920.13956", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-05-03T16:19:35Z", "type": "Journal Article", "created": "2017-10-13", "title": "Type VI secretion systems in plant-associated bacteria", "description": "SummaryThe type VI secretion system (T6SS) is a bacterial nanomachine used to inject effectors into prokaryotic or eukaryotic cells and is thus involved in both host manipulation and interbacterial competition. The T6SS is widespread among Gram\uffe2\uff80\uff90negative bacteria, mostly within the Proteobacterium Phylum. This secretion system is commonly found in commensal and pathogenic plant\uffe2\uff80\uff90associated bacteria. Phylogenetic analysis of phytobacterial T6SS clusters shows that they are distributed in the five main clades previously described (group 1\uffe2\uff80\uff935). The even distribution of the system among commensal and pathogenic phytobacteria suggests that the T6SS provides fitness and colonization advantages in planta and that the role of the T6SS is not restricted to virulence. This manuscript reviews the phylogeny and biological roles of the T6SS in plant\uffe2\uff80\uff90associated bacteria, highlighting a remarkable diversity both in terms of mechanism and function.
", "keywords": ["PROTEIN SECRETION", "0301 basic medicine", "570", "VIBRIO-CHOLERAE", "PATHOGENIC BACTERIA", "Microbiology", "03 medical and health sciences", "Bacterial Proteins", "Proteobacteria", "Phylogeny", "Plant Diseases", "2. Zero hunger", "0303 health sciences", "Science & Technology", "Virulence", "PSEUDOMONAS-AERUGINOSA", "Minireviews", "Plants", "Type VI Secretion Systems", "IN-SILICO ANALYSIS", "AGROBACTERIUM-TUMEFACIENS", "INTERBACTERIAL COMPETITION", "GENOMIC ANALYSIS", "EFFECTORS", "VIRULENCE", "Life Sciences & Biomedicine", "0605 Microbiology"]}, "links": [{"href": "https://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.13956"}, {"href": "https://doi.org/10.1111/1462-2920.13956"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Environmental%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/1462-2920.13956", "name": "item", "description": "10.1111/1462-2920.13956", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/1462-2920.13956"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-11-10T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=PROTEIN+SECRETION&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=PROTEIN+SECRETION&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=PROTEIN+SECRETION&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=PROTEIN+SECRETION&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-05-03T16:43:40.758497Z"}