{"database":"GEO","file_versions":[{"headers":{"Content-Type":["application/json"]},"body":{"files":{"Other":["ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE310nnn/GSE310590/"]},"type":"primary"},"statusCodeValue":200,"statusCode":"OK"}],"scores":null,"additional":{"omics_type":["Transcriptomics"],"species":["Dickeya dadantii 3937"],"gds_type":["Expression profiling by high throughput sequencing"],"full_dataset_link":["https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE310590"],"repository":["GEO"],"entry_type":["GSE"],"additional_accession":[]},"is_claimable":false,"name":"An endogenous auxin network shapes virulence and plant adaptation in Dickeya dadantii","description":"Indole-3-acetic acid (IAA) is a central phytohormone regulating plant growth and development and is increasingly recognized as an intra- and inter-kingdom signaling molecule that modulates diverse bacterial processes relevant during plant–microbe interactions. While IAA biosynthesis is widespread among plant-associated bacteria, the mechanisms through which this auxin regulates bacterial physiology and virulence, as well as those controlling its production, remain poorly understood. Here, we show that IAA synthesis deficiency in the globally relevant phytopathogen Dickeya dadantii triggers global transcriptional reprogramming and results in reduced virulence and fitness during plant infection. IAA was found to regulate the expression of the AaeXAB efflux pump, which mediates endogenous IAA secretion and confers resistance to plant defense–related phytohormones, including auxin and salicylic acid. This efflux system also contributes to successful plant infection and colonization in D. dadantii. Phylogenetic analyses revealed that the AaeXAB pump is commonly present among Pseudomonadota isolated from plant-associated environments. Moreover, IAA deficiency altered the expression of an indole-responsive regulator, suggesting cross-talk between IAA- and indole-mediated signaling networks. Our data also uncover a complex regulatory circuit coordination IAA production in D. dadantii, involving the ExpIR and Vfm quorum-sensing systems and the transcriptional regulators TyrR, TrpR, and LrhA. Collectively, our findings provide new insights into the role of IAA as a bacterial signal promoting plant adaptation and virulence. Targeting IAA biosynthesis and efflux pump activity may offer promising avenues for microbiome engineering and the development of anti-virulence strategies in phytopathogenesis.","dates":{"publication":"2026/07/02"},"accession":"GSE310590","cross_references":{"GSM":["GSM9304252","GSM9304247","GSM9304248","GSM9304249","GSM9304250","GSM9304251"],"GPL":["36333"],"GSE":["310590"],"taxon":["Dickeya dadantii 3937"]}}