Biology subjects

Jorda, L.

Publications and source records attributed to Jorda, L..

5 recordsLinked to original sources

bioRxiv2026

Yeast surface display reveals structure-dependent β-glucan association with the plant immune receptor AtIGP1

Cell wall-derived oligosaccharides can function as immune-active signals in plants and trigger pattern-triggered immunity (PTI) through pattern recognition receptors (PRRs). In Arabidopsis thaliana, the leucine-rich repeat malectin (LRR-MAL) receptor kinase IGP1 (impaired in glycan perception 1) contributes to immune responses induced by cellulose- and mixed-linkage {beta}-1,3/1,4-glucan (MLG)-derived oligosaccharides, although whether MLG-derived oligosaccharides are directly recognized by AtIGP1 needs further clarification. We established a Saccharomyces cerevisiae surface-display system in which the AtIGP1 extracellular domain (ECD) is presented at the yeast cell surface, allowing oligosaccharide recognition to be examined separately from downstream plant signaling and without receptor purification. Previously, cellulose-derived oligosaccharides have been shown to elicit plant defense responses via AtIGP1. Here, surface-displayed AtIGP1 retained the ability to recognize fluorescently labeled cellotriose (CEL3) and cellopentaose (CEL5) ligands, supporting functional presentation of the receptor for investigating glycan recognition in a heterologous context. Using this platform, we investigated the association of AtIGP1 with fluorescently labeled MLG-derived oligosaccharides differing in degree of polymerization (DP) and glycosidic linkage arrangement. This analysis revealed a specific, competitively displaceable association with MLG DP2 (G3G; laminaribiose), whereas the DP3 (G4G3G) and DP4 (G4G4G3G) structures tested showed no detectable association. To test whether this association is relevant in planta, we treated A. thaliana seedlings with unlabeled MLG DP2, which induced a cytosolic Ca2+ response, an early readout of immune activation. This response was markedly reduced in the igp1-3 mutant. Together, these results identify laminaribiose as an additional candidate ligand of AtIGP1. The established yeast surface-display platform thus provides an approach for testing candidate oligosaccharides for association with the extracellular domains of plant PRRs.

synthetic biology↗

bioRxiv2025

Glycan recognition by a plant sentinel immune receptor

Pathogens target and degrade the extracellular matrix surrounding plant cells. A central question is how cell wall-derived damage-associated molecular patterns (DAMPs) are recognized and integrated to trigger immune responses. We address this question by determining the structure of the multidomain receptor IGP1 in both apo form and bound to the cellulose-derived DAMP cellotriose. Structural analyses reveal that constitutive Leucine Rich Repeat-malectin interactions preconfigure IGP1 for ligand recognition and that the receptor features a highly specific sugar-binding pocket in the LRR domain capable of distinguishing fine variations in glycan structures. By directly sensing cello-oligomers, IGP1 acts as a cell wall sentinel that links pathogen-induced wall degradation to immune alerting, equipping plants to mount rapid and robust defense responses.

plant biology↗

bioRxiv2023

Signaling mechanisms and agricultural applications of (Z)-3-Hexenyl Butyrate-mediated stomatal closure

Biotic and abiotic stresses can severely limit crop productivity. In response to drought, plants close stomata to prevent water loss. Besides, stomata are considered the main entrance of several pathogens. Therefore, the development of natural products to control stomata closure can be considered a sustainable strategy to cope with stresses in agriculture. Plants respond to different stresses by releasing volatile organic compounds (VOCs). Green leaf volatiles (GLVs), which are commonly produced across different plant species after tissue damage, comprise an important group within VOCs. Among them, (Z)-3-hexenyl butyrate (HB) was described as a natural inducer of stomatal closure, playing an important role in stomatal immunity, although its mechanism of action is still unknown. Here, through different genetic, pharmacological, and biochemical approaches, we uncover that HB perception initiates various defense signaling events such as activation of Ca2+ permeable channels, mitogen-activated protein kinases (MPKs) and production of NADPH oxidase-mediated reactive oxygen species (ROS). Furthermore, HB-mediated stomata closure resulted to be independent of abscisic acid (ABA) biosynthesis and signaling. Additionally, exogenous treatments with HB alleviate water stress and improve fruit productivity in tomato plants. The efficacy of HB was also tested under open field conditions, leading to enhanced resistance against Phytophthora spp. and Pseudomonas syringae infection in potato and tomato plants, respectively. Taken together, our results provide insights into HB signaling transduction pathway, confirming its role in stomatal closure and plant immune system activation, and proposing HB as a new phytoprotectant for the sustainable control of biotic and abiotic stresses in agriculture.

molecular biology↗

bioRxiv2022

Prediction Of The Impact Of Genetic Variability On Drug Sensitivity For Clinically Relevant EGFR Mutations

Mutations in the kinase domain of the Epidermal Growth Factor Receptor (EGFR) can be drivers of cancer and also trigger drug resistance in patients under chemotherapy treatment based on kinase inhibitors use. A priori knowledge of the impact of EGFR variants on drug sensitivity would help to optimize chemotherapy and to design new drugs effective against resistant variants. To this end, we have explored a variety of in silico methods, from sequence-based to state-of-the-art atomistic simulations. We did not find any sequence signal that can provide clues on when a drug-related mutation appears and what will be the impact in drug activity. Low-level simulation methods provide limited qualitative information on regions where mutations are likely to produce alterations in drug activity and can predict around 70% of the impact of mutations on drug efficiency. High-level simulations based on non-equilibrium alchemical free energy calculations show predictive power. The integration of these state-of-the-art methods in a workflow implementing an interface for parallel distribution of the calculations allows its automatic and high-throughput use, even for researchers with moderate experience in molecular simulations.

biochemistry↗

bioRxiv2020

Arabidopsis thaliana Zn2+-efflux ATPases HMA2 and HMA4 are required for resistance to the necrotrophic fungus Plectosphaerella cucumerina BMM

O_LIZinc is an essential nutrient at low concentrations, but toxic at slightly higher ones. This could be used by plants to fight pathogens colonization. C_LIO_LIElemental distribution in Arabidopsis thaliana leaves inoculated with the necrotrophic fungus Plectosphaerella cucumerina BMM (PcBMM) was determined and compared to mock-inoculated ones. Infection assays were carried out in wild type and long-distance zinc trafficking double mutant hma2hma4, defective in root-to-shoot zinc partitioning. Expression levels of genes involved in zinc homeostasis or in defence phytohormone-mediated pathways were determined. C_LIO_LIZinc and manganese levels increased at the infection site. Zinc accumulation was absent in hma2hma4. HMA2 and HMA4 transcription levels were upregulated upon PcBMM inoculation. Consistent with a role of these genes in plant immunity, hma2hma4 mutants were more susceptible to PcBMM infection, phenotype rescued upon zinc supplementation. Transcript levels of genes involved in the salicylic acid, ethylene and jasmonate pathways were constitutively upregulated in hma2hma4 plants. C_LIO_LIThese data are consistent with a role of zinc in plant immunity not only of hyperaccumulator plants, but also of plants containing ordinary levels of zinc. This new layer of immunity seems to run in parallel to the already characterized defence pathways, and its removal has a direct effect on pathogen resistance. C_LI

plant biology↗