biostudies-literatureUnknown120(15)Gonin MThe establishment of beneficial interactions with microbes has helped plants to modulate root branching plasticity in response to environmental cues. However, how the plant microbiota harmonizes with plant roots to control their branching is unknown. Here, we show that the plant microbiota influences root branching in the model plant <i>Arabidopsis thaliana</i>. We define that the microbiota's ability to control some stages in root branching can be independent of the phytohormone auxin that directs lateral root development under axenic conditions. In addition, we revealed a microbiota-driven mechanism controlling lateral root development that requires the induction of ethylene response pathways. We show that the microbial effects on root branching can be relevant for plant responses to environmental stresses. Thus, we discovered a microbiota-driven regulatory pathway controlling root branching plasticity that could contribute to plant adaptation to different ecosystems.Proceedings of the National Academy of Sciences of the United States of Americae2301054120https://www.ebi.ac.uk/biostudies/studies/S-EPMC10104509biostudies-literaturePlant microbiota controls an alternative root branching regulatory mechanism in plants.PMC10104509Van de Poel BFrene JPGopaulchan DSalt DERoden SGonin MSalas-Gonzalez ICastrillo GfalsePlant microbiota controls an alternative root branching regulatory mechanism in plants.The establishment of beneficial interactions with microbes has helped plants to modulate root branching plasticity in response to environmental cues. However, how the plant microbiota harmonizes with plant roots to control their branching is unknown. Here, we show that the plant microbiota influences root branching in the model plant <i>Arabidopsis thaliana</i>. We define that the microbiota's ability to control some stages in root branching can be independent of the phytohormone auxin that directs lateral root development under axenic conditions. In addition, we revealed a microbiota-driven mechanism controlling lateral root development that requires the induction of ethylene response pathways. We show that the microbial effects on root branching can be relevant for plant responses to environmental stresses. Thus, we discovered a microbiota-driven regulatory pathway controlling root branching plasticity that could contribute to plant adaptation to different ecosystems.2023-01-01T00:00:00Z2023 Apr2024-11-09T05:03:59.911Z2024-11-09T05:03:59.911ZS-EPMC101045093701121310.1073/pnas.2301054120