Publications by authors named "Birgit Kemmerling"

Super-resolution microscopy (SRM) approaches revolutionize cell biology by providing insights into the nanoscale organization and dynamics of macromolecular assemblies and single molecules in living cells. A major hurdle limiting SRM democratization is post-acquisition data analysis which is often complex and time-consuming. Here, we present OneFlowTraX, a user-friendly and open-source software dedicated to the analysis of single-molecule localization microscopy (SMLM) approaches such as single-particle tracking photoactivated localization microscopy (sptPALM).

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BRI1-ASSOCIATED KINASE 1 (BAK1/SERK3) and its closest homolog BAK1-LIKE 1 (BKK1/SERK4) are leucine-rich repeat receptor kinases (LRR-RKs) belonging to the SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK) family. They act as co-receptors of various other LRR-RKs and participate in multiple signaling events by complexing and transphosphorylating ligand-binding receptors. Initially identified as the brassinosteroid receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) co-receptor, BAK1 also functions in plant immunity by interacting with pattern recognition receptors.

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Interaction of engineered nanomaterials (ENMs) with the immune system mainly occurs with cells and molecules of innate immunity, which are present in interface tissues of living organisms. Immuno-nanotoxicological studies aim at understanding if and when such interaction is inconsequential or may cause irreparable damage. Since innate immunity is the first line of immune reactivity towards exogenous agents and is highly conserved throughout evolution, this review focuses on the major effector cells of innate immunity, the phagocytes, and their major sensing receptors, Toll-like receptors (TLRs), for assessing the modes of successful versus pathological interaction between ENMs and host defences.

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Arabidopsis BAK1/SERK3, a co-receptor of leucine-rich repeat pattern recognition receptors (PRRs), mediates pattern-triggered immunity (PTI). Genetic inactivation of BAK1 or BAK1-interacting receptor-like kinases (BIRs) causes cell death, but the direct mechanisms leading to such deregulation remains unclear. Here, we found that the TIR-NBS-LRR protein CONSTITUTIVE SHADE AVOIDANCE 1 (CSA1) physically interacts with BIR3, but not with BAK1.

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Plants are indispensable on earth and their improvement in terms of food security is a need of time. The current study has been designed to investigate how biogenic zinc nanoparticles (Zn NPs) can improve the growth and development of L. In this study, Zn NPs were synthesized utilizing aqueous extracts, and their morphological and optical properties were assessed using UV-Visible spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD).

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Article Synopsis
  • * Research on gold nanoparticles (AuNPs) shows they may promote plant growth rather than causing stress, enhancing root growth and reducing oxidative stress responses.
  • * Molecular analyses indicate that AuNP exposure downregulates oxidative stress responses and upregulates genes related to growth, providing a basis for further study on how AuNPs influence plant development.
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The use of nanomaterials in agriculture is a current need and could be helpful in overcoming food security risks. Brassica napus L. is the third most important crop for edible oil, having double low unsaturated fatty acids.

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Plants utilize a two-tiered immune system consisting of pattern recognition receptor (PRR)-triggered immunity (PTI) and effector-triggered immunity (ETI) to defend themselves against pathogenic microbes. The receptor protein kinase BAK1 plays a central role in multiple PTI signaling pathways in However, double mutants made by and its closest paralog exhibit autoimmune phenotypes, including cell death resembling a typical nucleotide-binding leucine-rich repeat protein (NLR)-mediated ETI response. The molecular mechanisms of the cell death caused by the depletion of BAK1 and BKK1 are poorly understood.

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The interaction of a living organism with external foreign agents is a central issue for its survival and adaptation to the environment. Nanosafety should be considered within this perspective, and it should be examined that how different organisms interact with engineered nanomaterials (NM) by either mounting a defensive response or by physiologically adapting to them. Herein, the interaction of NM with one of the major biological systems deputed to recognition of and response to foreign challenges, i.

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Brassinosteroids (BR) are involved in the control of several developmental processes ranging from root elongation to senescence and adaptation to environmental cues. Thus, BR perception and signaling have to be precisely regulated. One regulator is BRI1-associated kinase 1 (BAK1)-interacting receptor-like kinase 3 (BIR3).

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BAK1 is a coreceptor and positive regulator of multiple ligand binding leucine-rich repeat receptor kinases (LRR-RKs) and is involved in brassinosteroid (BR)-dependent growth and development, innate immunity, and cell death control. The BAK1-interacting LRR-RKs BIR2 and BIR3 were previously identified by proteomics analyses of in vivo BAK1 complexes. Here, we show that BAK1-related pathways such as innate immunity and cell death control are affected by BIR3 in BIR3 also has a strong negative impact on BR signaling.

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Secreted peptides and their specific receptors frequently orchestrate cell-to-cell communication in plants. Phytosulfokines (PSKs) are secreted tyrosine-sulphated peptide hormones, which trigger cellular dedifferentiation and redifferentiation upon binding to their membrane receptor. Biotrophic plant pathogens frequently trigger the differentiation of host cells into specialized feeding structures, which are essential for successful infection.

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Plants detect pathogens by sensing microbe-associated molecular patterns (MAMPs) through pattern recognition receptors. Pattern recognition receptor complexes also have roles in cell death control, but the underlying mechanisms are poorly understood. Here, we report isolation of cerk1-4, a novel mutant allele of the Arabidopsis chitin receptor CERK1 with enhanced defense responses.

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Amino acid transporters in plants are crucial for distributing amino acids between plant organs and cellular compartments. The H(+)-coupled plasma membrane transporter CAT1 (cationic amino acid transporter 1) facilitates the high-affinity uptake of basic amino acids. The uptake of lysine (Lys) via the roots was not altered in loss-of-function mutants, in accordance with the minor expression of CAT1 in roots, but plants ectopically overexpressing CAT1 incorporated Lys at higher rates.

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BAK1 is a multifunctional leucine-rich repeat receptor kinase (LRR-RLK) that exerts its function by interacting with multiple ligand binding receptors and thereby influences diverse processes varying from brassinosteroid perception via PAMP and DAMP perception to cell death control. We recently identified a new BAK1 interacting protein, BIR2, that is also a LRR-RLK but, in contrast to BAK1, negatively regulates BAK1-dependent PAMP responses. While brassinosteroid responses are not affected by BIR2, cell death is negatively regulated as described for BAK1.

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The BAK1-interacting receptor-like kinase 2 (BIR2) belongs to the large family of leucine-rich repeat receptor-like kinases (LRR-RLKs) that mediate development and innate immunity in plants and form a monophyletic gene family with the Drosophila Pelle and human interleukin-1 receptor-associated kinases (IRAK). BIR2 is a negative regulator of BAK1-mediated defense mechanisms and cell death responses, yet key residues that are typically required for kinase activity are not present in the BIR2 kinase domain. We have determined the crystal structure of the BIR2 cytosolic domain and show that its nucleotide binding site is occluded.

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Background: Transmembrane leucine-rich repeat (LRR) receptors are commonly used innate immune receptors in plants and animals but can also sense endogenous signals to regulate development. BAK1 is a plant LRR-receptor-like kinase (RLK) that interacts with several ligand-binding LRR-RLKs to positively regulate their functions. BAK1 is involved in brassinosteroid-dependent growth and development, innate immunity, and cell-death control by interacting with the brassinosteroid receptor BRI1, immune receptors, such as FLS2 and EFR, and the small receptor kinase BIR1, respectively.

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Plant peptide signaling is an upcoming topic in many areas of plant research. Our recent findings show that the tyrosine sulfated peptide receptors PSKR1 and PSY1R are not only involved in growth and development but also in plant defense. They modulate salicylate- and jasmonate-dependent defense pathways in an antagonistic manner and this phenomenon might be dependent on the age and developmental stage of the plant.

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Recognition of molecular patterns characteristic of microbes or altered-self leads to immune activation in multicellular eukaryotes. In Arabidopsis thaliana, the leucine-rich-repeat receptor kinases FLAGELLIN-SENSING2 (FLS2) and EF-TU RECEPTOR (EFR) recognize bacterial flagellin and elongation factor EF-Tu (and their elicitor-active epitopes flg22 and elf18), respectively. Likewise, PEP1 RECEPTOR1 (PEPR1) and PEPR2 recognize the elicitor-active Pep epitopes conserved in Arabidopsis ELICITOR PEPTIDE PRECURSORs (PROPEPs).

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The tyrosine-sulfated peptides PSKα and PSY1 bind to specific leucine-rich repeat surface receptor kinases and control cell proliferation in plants. In a reverse genetic screen, we identified the phytosulfokine (PSK) receptor PSKR1 as an important component of plant defense. Multiple independent loss-of-function mutants in PSKR1 are more resistant to biotrophic bacteria, show enhanced pathogen-associated molecular pattern responses and less lesion formation after infection with the bacterial pathogen Pseudomonas syringae pv.

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Receptor-like kinases (RLK) are among the largest gene families encoded by plant genomes. Common structural features of plant RLKs are an extracellular ligand binding domain, a membrane spanning domain, and an intracellular protein kinase domain. The largest subfamily of plant RLKs is characterized by extracellular leucine-rich repeat (LRR-RLK) structures that are known biochemical modules for mediating ligand binding and protein-protein interactions.

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At least two components that modulate plant resistance against the fungal powdery mildew disease are ancient and have been conserved since the time of the monocot-dicot split (≈ 200 Mya). These components are the seven transmembrane domain containing MLO/MLO2 protein and the syntaxin ROR2/PEN1, which act antagonistically and have been identified in the monocot barley (Hordeum vulgare) and the dicot Arabidopsis thaliana, respectively. Additionally, syntaxin-interacting N-ethylmaleimide sensitive factor adaptor protein receptor proteins (VAMP721/722 and SNAP33/34) as well as a myrosinase (PEN2) and an ABC transporter (PEN3) contribute to antifungal resistance in both barley and/or Arabidopsis.

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Plasma membrane-borne pattern recognition receptors, which recognize microbe-associated molecular patterns and endogenous damage-associated molecular patterns, provide the first line of defense in innate immunity. In plants, leucine-rich repeat receptor kinases fulfill this role, as exemplified by FLS2 and EFR, the receptors for the microbe-associated molecular patterns flagellin and elongation factor Tu. Here we examined the perception of the damage-associated molecular pattern peptide 1 (AtPep1), an endogenous peptide of Arabidopsis identified earlier and shown to be perceived by the leucine-rich repeat protein kinase PEPR1.

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Plant receptor-like kinases (RLKs) are transmembrane proteins with putative N-terminal extracellular ligand-binding domains and C-terminal intracellular protein kinase domains. RLKs have been implicated in multiple physiological programs including plant development and immunity to microbial infection. Arabidopsis thaliana gene expression patterns support an important role of this class of proteins in biotic stress adaptation.

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