Biology subjects

Barberon, M.

Publications and source records attributed to Barberon, M..

8 recordsLinked to original sources

bioRxiv2026

Morph-specific plasticity drives divergent host-shift and acclimation strategies in aphids

Understanding how organisms cope with environmental change is central to eco-evolutionary theory, yet a key unresolved challenge is distinguishing anticipatory plasticity, where phenotypes are pre-configured using predictive cues, from responsive plasticity, where phenotypes are adjusted after environmental exposure. Empirically testing these strategies is challenging because phenotypes measured after environmental transitions integrate both prior cue-dependent state configuration and post-exposure adjustment, obscuring when plastic responses are initiated. Systems with predictable environmental transitions and discrete life-history stages provide a powerful opportunity to resolve this challenge. Here, we use host-alternating aphids to test how plasticity strategies are organized across morphs experiencing the same seasonal host shift but facing different ecological constraints. We quantified fitness, transcriptomic responses, and host chemical landscapes across three morphs transferred among secondary hosts differing in phloem composition. Migratory spring morphs maintained uniformly high survival and showed minimal transcriptional change, consistent with anticipatory plasticity mediated by pre-configured metabolic and detoxification programs. In contrast, summer morphs exhibited host-dependent survival costs and extensive regulatory remodeling, indicating responsive plasticity. By integrating fitness, transcriptomics, and metabolomics, we show that predictable environmental transitions can favor the evolution and partitioning of plasticity strategies across life-history stages. More broadly, our results provide mechanistic evidence linking environmental predictability, regulatory architecture, and the evolution of plastic responses to heterogeneous environments.

evolutionary biology↗

bioRxiv2025

GWAs reveals SUBER GENE1-mediated suberization via Type One Phosphatases

Suberin deposition in the root endodermis is critical for plant nutrient acquisition and environmental adaptation. Here, we used an unbiased forward genetic approach based on natural variation across 284 Arabidopsis thaliana accessions to identify novel regulators of endodermal suberization. This screen revealed striking diversity in suberin levels and patterns, uncovering broader roles for suberin beyond those observed in the reference accession Col-0. A genome-wide association study pinpointed SUBER GENE1 (SBG1), a previously uncharacterized gene encoding a 129-amino acid protein, as a key regulator of suberin deposition. SBG1 acts through physical interaction with type one protein phosphatases (TOPPs) via conserved SILK and RVxF motifs. Disrupting this interaction abolishes SBG1 function, while topp mutants exhibit enhanced endodermal suberization, mirroring SBG1 overexpression. Our findings uncover a previously unknown regulatory module linking suberin formation to TOPP activity and ABA signaling and provide a framework for improving plant stress resilience through targeted manipulation of root barrier properties.

plant biology↗

bioRxiv2024

Four ZIPs contribute to Zn, Fe, Cu and Mn acquisition at the outer root domain

Zinc (Zn), an essential micronutrient, plays a crucial role in plant development. However, the specific transporters involved in Zn uptake from the soil remain unclear in dicotyledonous. Using promoter-reporter lines in Arabidopsis thaliana, we identified several ZIP (Zn-regulated transporter, Iron-regulated transporter (IRT)-like Protein) family members that are expressed in the epidermis and potentially involved in Zn acquisition from the outer root domain. ZIP2, ZIP3, ZIP5 and ZIP8 predominantly localize to the plasma membrane of epidermal and cortical cells, supporting their potential roles in metal uptake from the soil. Through physiology studies, ionomic profiling and genetic analysis, we determined that ZIP3 and ZIP5 are key contributors to Zn acquisition, while ZIP2 and ZIP8 are primarily involved in copper (Cu) and iron (Fe) acquisition respectively. Notably, ZIP3 and ZIP8 exhibit outer polarity in root epidermal cells, similar to IRT1, underscoring the significance of transporter polarity in mineral acquisition. These findings provide new insights into the mechanisms of metal uptake in plant roots and offer potential strategies for biofortification to enhance metal content in plants.

plant biology↗

bioRxiv2024

Directional Cell-to-cell Transport in Plant Roots

Cell-to-cell communication is critical for multicellular organisms. In plants, plasmodesmata--cytoplasmic channels--enable molecular transport between adjacent cells. In roots, this transport is predicted to be essential in nutrient acquisition and delivery to the vasculature. We demonstrate that plasmodesmatal transport persists in differentiated roots, despite apoplastic barriers such as Casparian strips and suberin lamellae in the endodermis, suggesting plasmodesmata as the sole pathway for water and nutrient flow at this stage. We also reveal a developmental switch in plasmodesmata function resulting in an unidirectional transport in differentiated roots. A genetic screen identified mutations that disrupt this directionality, leading to bidirectional transport. These mutations correlate with larger plasmodesmatal apertures, linked to defects in pectin composition and cell wall organization. This discovery underscores the role of plasmodesmatal aperture regulation and pectin in controlling directional transport. Our findings provide insights into plasmodesmata function and their regulation in roots.

plant biology↗

bioRxiv2024

Temperature-dependent polar lignification of a seed coat suberin layer promoting dormancy in Arabidopsis thaliana

The seed is a landmark plant adaptation where the embryo is sheltered by a protective seed coat to facilitate dispersion. In Arabidopsis, the seed coat, derived from ovular integuments, plays a critical role in maintaining dormancy, ensuring germination occurs during a favorable season. Dormancy is enhanced by cold temperatures during seed development by affecting seed coat permeability through changes in apoplastic barriers. However, the localization and composition of these apoplastic barriers are poorly understood. This study identifies and investigates a polar barrier in the seed coats outer integument (oi1) cells. We present histological, biochemical, and genetic evidence showing that cold promotes polar seed coat lignification of the outer integument 1 (oi1) cells and suberization throughout the entire oi1 cell boundary. The polar oi1 barrier is regulated by the transcription factors MYB107 and MYB9. MYB107, in particular, is crucial for the lignified polar oi1 barrier formation under cold temperatures. The absence of the oi1 barrier in mutant seeds correlates with increased permeability and reduced dormancy. Our findings elucidate how temperature-induced modifications in seed coat composition regulate dormancy, highlighting the roles of suberin and lignin in this process. Significance statementOur study uncovers how cold temperatures during seed development in the mother plant influence seed dormancy through apoplastic modifications in the Arabidopsis thaliana seed coat. We identified a polar lignin barrier in the outer integument 1 (oi1) cells, which are also suberized. Lignification and suberization are regulated by transcription factors MYB107 and MYB9. Cold promotes lignification and suberization of oi1 cells through MYB107, thus creating a "memory" that reduces seed permeability and strengthens dormancy. Mutants defective in the oi1 barrier exhibit lower dormancy, highlighting the adaptive importance of this barrier. These findings advance our understanding of temperature-induced seed coat adaptations and their agricultural implications, particularly in the context of climate change, offering valuable insights for improving crop resilience and yield.

plant biology↗

bioRxiv2021

Extracellular membrane tubules involved in suberin deposition in plant cell walls

Suberin is a fundamental plant biopolymer, found in protective tissues, such as seed coats, exodermis and endodermis of roots, the outer layers of stems and roots with secondary growth, as well as in wound-induced tissues. Its presence allows organs to resist various environmental stresses, such as pathogen attack, drought or excessive salt concentrations. Suberin is a mostly aliphatic polyester of long-chain fatty acids and alcohols, often co-occurring with lignin-like polymers in the same cells. Most suberizing cells appear to deposit suberin in the form of lamellae just outside of the plasma membrane, below the primary cell wall. The monomeric precursors of suberin are thought to be glycerated fatty acids, synthesized at the endoplasmic reticulum. However, it has remained obscure how these monomers are transported outside of the cell, where they will be polymerized to form suberin lamellae. Here, we demonstrate that extracellular vesicular-tubular structures accumulate specifically in suberizing cells. By employing various, independent mutational and hormonal challenges, known to affect suberization in distinct ways, we demonstrate that their presence correlates perfectly with root suberization. Surprisingly, no endosomal compartment marker showed any conspicuous changes upon induction of suberization, suggesting that this compartment might not derive from endosomal multi-vesicular bodies, but possibly form directly from endoplasmic reticulum subdomains. Consistent with this, we could block formation of both, suberin deposition and vesicle accumulation by a pharmacogenetic manipulation affecting early steps in the secretory pathway. Whereas many previous reports have described extracellular vesicle occurrence in the context of biotic interactions, our results suggest a developmental role for extracellular vesicles in suberin formation. One Sentence SummarySuberin lamellae formation is associated with extracellular membrane tubules.

plant biology↗

bioRxiv2021

Suberin plasticity to developmental and exogenous cues is regulated by a set of MYB transcription factors

Suberin is a hydrophobic biopolymer that can be deposited at the periphery of cells, forming protective barriers against biotic and abiotic stress. In roots, suberin forms lamellae at the periphery of endodermal cells where it plays crucial roles in the control of water and mineral transport. Suberin formation is highly regulated by developmental and environmental cues. However, the mechanisms controlling its spatiotemporal regulation are poorly understood. Here, we show that endodermal suberin is regulated independently by developmental and exogenous signals to fine tune suberin deposition in roots. We found a set of four MYB transcription factors (MYB41, MYB53, MYB92 and MYB93), that are regulated by these two signals, and are sufficient to promote endodermal suberin. Mutation of these four transcription factors simultaneously through genome editing, lead to a dramatic reduction of suberin formation in response to both developmental and environmental signals. Most suberin mutants analyzed at physiological levels are also affected in another endodermal barrier made of lignin (Casparian strips), through a compensatory mechanism. Through the functional analysis of these four MYBs we generated plants allowing unbiased investigations of endodermal suberin function without accounting for confounding effects due to Casparian strip defects, and could unravel specific roles of suberin in nutrient homeostasis.

plant biology↗

bioRxiv2020

Constitutive activation of leucine-rich repeat receptor kinase signaling pathways by BAK1-interacting receptor-like kinase 3 chimera

Receptor kinases with extracellular leucine-rich repeat domains (LRR-RKs) form the largest group of membrane signaling proteins in plants. LRR-RKs can sense small molecule, peptide or protein ligands, and may be activated by ligand-induced interaction with a shape complementary SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) co-receptor kinase. We have previously shown that SERKs can also form constitutive, ligand-independent complexes with the LRR ectodomains of BAK1-interacting receptor-like kinase 3 (BIR3) receptor pseudokinases, negative regulators of LRR-RK signaling. Here we report that receptor chimaera in which the extracellular LRR domain of BIR3 is fused to the cytoplasmic kinase domains of the SERK-dependent LRR-RKs BRASSINOSTEROID INSENSITIVE1, HAESA and ERECTA form tight complexes with endogenous SERK co-receptors in the absence of ligand stimulus. Expression of these chimaera under the control of the endogenous promoter of the respective LRR-RK leads to strong gain-of-function brassinosteroid, floral abscission and stomatal patterning phenotypes, respectively. Importantly, a BIR3-GSO1/SGN3 chimera can partially complement sgn3 Casparian strip formation phenotypes, suggesting that GSO1/SGN3 receptor activation is also mediated by SERK proteins. Collectively, our protein engineering approach may be used to elucidate the physiological functions of orphan LRR-RKs and to identify their receptor activation mechanism in single transgenic lines.

plant biology↗