Systemic control of root developmental plasticity
Plants continuously adjust their root system architecture to changes in nutrient availability. Our team investigates the molecular mechanisms underlying this developmental plasticity, with a particular focus on long-distance signaling between shoots and roots.
Using white lupin as a model, we study the AoDev/AoN systemic regulatory pathways that coordinate root developmental responses to phosphorus and nitrogen availability. Our recent work has identified the leucine-rich repeat receptor kinase LalbCCR1 as a component involved in the systemic regulation of cluster root and nodule development.
Our goal is to understand how nutrient perception and systemic signaling are integrated to coordinate root developmental programs and optimize plant adaptation to nutrient-limited environments.
Cluster roots as a model for adaptive organogenesis
White lupin (Lupinus albus) develops specialized clusters of short lateral roots, known as cluster roots, in response to phosphorus deficiency. These structures represent a remarkable example of developmental plasticity, allowing plants to enhance nutrient acquisition in nutrient-poor soils.
We investigate the mechanisms controlling cluster root initiation, developmental patterning and coordination with other root organs. Particular attention is given to the integration of local and systemic signals, including the interactions between nutrient availability, cluster root formation and symbiotic nodulation.
By studying these specialized organs, we aim to identify developmental principles underlying the remarkable capacity of plant root systems to adapt to their environment.
Cell wall remodeling and root morphogenesis
Root organogenesis requires coordinated changes in cell identity, tissue mechanics and cell wall properties. Our team investigates how cell wall remodeling contributes to the initiation and emergence of new root organs.
We combine single-nucleus transcriptomics, quantitative imaging of cell wall polysaccharides, gene family analyses and developmental modeling to explore the relationships between gene expression, cell wall composition and tissue morphogenesis.
These approaches have contributed to the development of a "push-and-yield" conceptual framework, in which coordinated changes in cell wall properties and mechanical interactions facilitate lateral root formation.
Comparative and evolutionary perspectives
How conserved are the cellular mechanisms underlying root development across plant species?
To address this question, we compare root morphogenesis in species with contrasting developmental strategies and cell wall architectures, including white lupin and the model grass Brachypodium distachyon.
By integrating comparative transcriptomics, cell wall characterization and quantitative imaging, we investigate the conservation and diversification of the mechanisms governing root organogenesis.
This research is notably supported by the Marie Skłodowska-Curie postdoctoral project of Kevin Bellande.
Genomic resources for white lupin
Our team has contributed to the development of genomic resources that have established white lupin as a model for studying root development, nutrient acquisition and genetic diversity.
These include a high-quality reference genome and a species-wide pangenome integrating cultivated and wild accessions, providing insights into structural variation and gene content diversity.
Together, these resources support comparative genomics, functional genetics and the identification of genetic determinants associated with adaptive root traits.
These datasets are accessible through the White Lupin Genome Portal www.whitelupin.fr
PULSAR – systemic regulation and genetic dissection of root traits
Within the ANR France 2030 PULSAR project, we investigate the genetic and developmental mechanisms underlying root system adaptation to nutrient limitation in white lupin.
We combine large-scale root phenotyping, genome-wide association studies (GWAS) and functional genetics to identify genetic determinants of root architecture and cluster root development across diverse lupin accessions.
Candidate genes emerging from these approaches are investigated using molecular and reverse-genetic strategies, including the development of a dedicated TILLING/FIND-IT platform.
PULSAR brings together academic and private partners to connect fundamental discoveries in root developmental biology with the development of nutrient-efficient lupin varieties.
Root phenotyping and imaging platforms
Understanding root developmental plasticity requires quantitative and reproducible phenotyping across multiple biological scales.
Our team develops and uses complementary experimental systems, including controlled growth conditions for cluster root induction, advanced imaging approaches and RhizoARCH, a root phenotyping system designed to characterize root system architecture in white lupin.
RhizoARCH enables the quantitative analysis of architectural traits across genetically diverse accessions, providing a framework to investigate natural variation in root development and its responses to environmental conditions.
By integrating root phenotyping with cellular imaging, molecular analyses and genetic approaches, we aim to connect whole-root system architecture with the mechanisms controlling organ formation and development.
MAIN COLLABORATIONS
PULSAR Project
Coordinator Joëlle Fustec - Ecole Supérieure d'Agricultures (ESA) Angers FR
INRAE Partners IPSiM Montpellier, Agroécologie Dijon, STLO Rennes, IRHS Angers, BIA Nantes
Private partners Cérience Poitiers, Kédelaï Paris
Cell wall and cluster root development
Joop Vermeer - Université de Neuchâtel - Switzerland
MSCA Global Fellowship to Kevin Bellande
Cluster root development and auxin
Hirotsuna Yamada - University of Hiroshima - Japan
ASPIRE Program
Autoregulation of cluster root and nodule development
Florian Frugier - IPS2 Saclay - France
Projet ANR LEG-SYS