Hydraulic flux–responsive hormone redistribution determines root branching

Mehra, Poonam [ Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, UK.] Pandey, Bipin K. [ Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, UK.] Melebari, Dalia [ Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, UK.] Banda, Jason [ Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, UK.] Leftley, Nicola [ Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, UK.] Couvreur, Valentin [UCL] Rowe, James [Sainsbury Laboratory, University of Cambridge, Cambridge, UK] Anfang, Moran [School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israe] De Gernier, Hugues [Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium] Morris, Emily [Sainsbury Laboratory, University of Cambridge, Cambridge, UK] Sturrock, Craig J. [Sainsbury Laboratory, University of Cambridge, Cambridge, UK] Mooney, Sacha J. [Sainsbury Laboratory, University of Cambridge, Cambridge, UK] Swarup, Ranjan [Sainsbury Laboratory, University of Cambridge, Cambridge, UK] Faulkner, Christine [Crop Genetics, John Innes Centre, Norwich Research Park, Norwich, UK] Beeckman, Tom [Sainsbury Laboratory, University of Cambridge, Cambridge, UK] Bhalerao, Rishikesh P. [Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 87 Umeå, Sweden] Shani, Eilon [School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israe] Jones, Alexander M. [Sainsbury Laboratory, University of Cambridge, Cambridge, UK] Dodd, Ian C. [Lancaster Environment Centre, Lancaster University, Lancaster, UK.] Sharp, Robert E. [0Division of Plant Science and Technology, University of Missouri, Columbia, MO, USA] Sadanandom, Ari [Department of Biosciences, University of Durham, Durham, UK] Draye, Xavier [UCL] Bennett, Malcolm J. [ Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, UK.] et al.[show all]

Plant roots exhibit plasticity in their branching patterns to forage efficiently for heterogeneously distributed resources, such as soil water. The xerobranching response represses lateral root formation when roots lose contact with water. Here, we show that xerobranching is regulated by radial movement of the phloem-derived hormone abscisic acid, which disrupts intercellular communication between inner and outer cell layers through plasmodesmata. Closure of these intercellular pores disrupts the inward movement of the hormone signal auxin, blocking lateral root branching. Once root tips regain contact with moisture, the abscisic acid response rapidly attenuates. Our study reveals how roots adapt their branching pattern to heterogeneous soil water conditions by linking changes in hydraulic flux with dynamic hormone redistribution