Biology subjects

Skirycz, A.

Publications and source records attributed to Skirycz, A..

At least 19 recordsLinked to original sources

bioRxiv2026

Hopeaphenol targets histidine kinase signaling across kingdoms to suppress bacterial virulence and potentiate plant immunity

Small molecules can control plant disease either by disarming the pathogen or by priming host immunity, but single compounds that do both are rare and mechanistically unexplained. Here we show that hopeaphenol (HP), a resveratrol tetramer from stilbene producing plants, acts on histidine kinase (HK) signaling on both sides of the Arabidopsis-Pseudomonas interaction. In Pseudomonas syringae pv. tomato DC3000, HP represses the type III secretion regulon and motility genes, restricts surface motility independently of effector delivery, and binds a defined subset of virulence-associated sensor kinases while reducing their autophosphorylation; comparable engagement occurs in Pectobacterium atrosepticum. Binding and inhibition depend on the tetrameric scaffold rather than the resveratrol monomer. In the host, HP binds the CHASE domains of the cytokinin receptors AHK2, AHK3 and AHK4 and elicits an immune-associated, rather than canonical cytokinin, transcriptional output. HP-dependent potentiation of PTI and ETI responses and early restriction of bacterial growth require AHK3 and AHK4. HP thus coordinates opposing outputs from divergent HK systems across kingdoms.

plant biology↗

bioRxiv2026

Cystinosin/Ers1 functions in redox homeostasis in the early secretory pathway

Cystinosis is an autosomal recessive inherited disorder caused by mutations in the CTNS gene, which encodes the highly conserved transmembrane protein cystinosin, a proton/cystine co-transporter at the lysosome membrane. However, reduction of cystine load in the lysosomes is insufficient to treat key disease symptoms, indicating that cystinosin performs additional disease-relevant functions. Here, we report that Ers1, the yeast homolog of cystinosin, localizes to and functions in the early secretory pathway. We provide evidence that Ers1 does not transport cystine. Ers1 genetically interacts with early secretory pathway recycling adaptors and redox-active Fe-S cluster-binding proteins. Notably, cystinosin-LKG, the extra-lysosomal localized splicing isoform of cystinosin, can functionally replace Ers1 in yeast. Collectively, our work uncovers a conserved role of cystinosin/Ers1 in the early secretory pathway, offering new molecular insights for understanding cystinosis pathology.

cell biology↗

bioRxiv2026

Multi-tissue metabolic GWAS and drought-responsive multi-omics reveal the genetic basis of the quinoa metabolome

Quinoa (Chenopodium quinoa) is a nutrient-rich pseudocereal with diverse specialized metabolites, yet the genetic basis of this metabolic diversity is poorly understood. Here we integrate whole-genome sequencing and multi-tissue metabolic profiling of 603 quinoa accessions. We detected 4,688 metabolic features and identified over 1,000 metabolites in seeds, leaves, and roots. Using multi-tissue genome-wide association, we mapped the genetic architecture of quinoa metabolome by identifying 584 quantitative trait loci (QTL) and prioritized 219 candidate genes across 58 major QTL governing saponin, betalain, and flavonoid biosynthesis. Moreover, we constructed a drought-responsive multi-omics regulatory network and uncovered additional key genes involved in quinoa stress signalling and metabolic pathways. Finally, we cloned and functional validated the roles of CYP76AD1 in betalamate accumulation, UGT91C1 in flavonoid glycosylation, and CYP72A154 and soyasapogenol B glucuronide galactosyltransferase (SGT) in saponin biosynthesis. This multi-omic framework provides a high-resolution map of the quinoa metabolome and a foundation for breeding nutrient-rich and stress-resilient quinoa cultivars.

plant biology↗

bioRxiv2025

Chemical modulation of chloroplast de- and re-differentiation reveals a role for the SAL1-PAP retrograde pathway in facilitating plastid transitions

Plastids are dynamic organelles that remodel their composition, ultrastructure, and function according to developmental and environmental demands. The synthetic molecule X57 induces the conversion of leaf chloroplasts into tocopherol-rich plastids lacking thylakoids and containing proliferating plastoglobules. Removal of X57 triggers chloroplast re-differentiation, enabling precise spatial-temporal dissection of these transitions. X57 directly binds and inhibits the phosphatase SAL1, causing accumulation of its substrate 3'-phosphoadenosine 5'-phosphate (PAP), a retrograde signal that modulates nuclear gene expression. SAL1 inhibition and subsequent PAP accumulation activate a cascade that depletes cytokinins and down-regulates GOLDEN2-LIKE1 (GLK1) and other transcription factors involved in chloroplast biogenesis. SAL1-defective mutants fail to undergo this signaling pathway. The SAL1-PAP-mediated weakening of chloroplast identity preconditions plastids for their eventual conversion into storage-type organelles upon X57-promoted accumulation of tocopherols. After X57 withdrawal, photosynthetic gene expression and chloroplast functions are restored. This framework identifies key molecular mechanisms underlying chloroplast plasticity, a central process in biology.

plant biology↗

bioRxiv2025

Identification of dehydrin protein complexes in vivo reveals functional interactions of LEA5 with OSCA3, PIP2B and PLDα1 in plant water-deficit stress

Climate change and especially the concomitant increasing frequency of drought and salinity induced water-deficit stresses, is a major limiting factor of plant growth and crop productivity worldwide. Understanding the adaptive responses of plants to water-deficit stress has therefore become a central challenge in plant biotechnology. Considerable evidence indicates that late embryogenesis abundant (LEA) proteins contribute to water-deficit stress tolerance and the stabilization of metabolic enzymes, yet the molecular basis of these responses remains unknown. To date, limited direct evidence for specific in vivo interactions between LEA proteins and their molecular targets has been reported. Here, we identify for the first time the native in vivo interactome of three Arabidopsis dehydrin LEA proteins - LEA4 (COR47), LEA5 (ERD10), and LEA10 (ERD14) - expressed under their own promoters and in response to salt stress. Our results show that LEA4, LEA5, and LEA10 dehydrins interact with each other, and share six common candidate protein interactors, suggesting that they form a core protein complex in salt stress conditions. We confirmed the direct protein-protein interaction between LEA5 with LEA4, LEA10, OSCA3, PLD1, PIP2B and OST1/AHA1 at the biochemical level. Phenotypic analyses of loss-of-function genetic mutants revealed that the interactions of LEA5 with OSCA3 and PIP2B promote seed germination under salt stress. LEA5 interaction with PLD1 promotes root growth under salt stress, while its interaction with PIP2B enhances root growth under osmotic stress, indicating distinct stress-specific functional roles for each interaction. In conclusion, this study identifies the native in vivo interactions of three dehydrin proteins, while uncovering the functional relevance of these interactions under salt and osmotic stress conditions, thus providing novel mechanistic insights into the role of LEA proteins in water-deficit stress adaptation.

plant biology↗

bioRxiv2025

Multi-Omics Analysis of Heat Stress-Induced Memory in Arabidopsis

In their natural environment, plants experience temperature fluctuations, including intensified heat waves driven by climate change, which pose significant threats to their productivity. To adapt, plants have evolved diverse mechanisms to withstand heat stress (HS), minimizing potential damage and ensuring survival. One such adaptation is acquired thermotolerance (AT), where prior exposure to HS primes plants to withstand subsequent severe HS. AT can persist for several days and involves a recovery period during which plants establish heat stress memory (HSM), reorganize cellular processes, and strengthen stress resilience. The molecular mechanisms underlying HSM remain the subject of active investigation. In this study, we employ a high-throughput comparative multi-omics approach to unravel the transcriptome, metabolome, and proteome of Arabidopsis thaliana seedlings during distinct intervals of the HSM phase. Our findings provide insights into the intricacies of HS recovery and the memory process. Notably, distinct temporal responses emerge at both the transcriptional and protein levels during the early and late recovery phases. Transcripts associated with HSM are upregulated during the early HS recovery phase, indicating a rapid response crucial for initial memory formation, while corresponding protein levels remain elevated throughout the recovery period, supporting memory consolidation. Additionally, metabolite profiles reveal distinctive patterns across the HS memory phase. This marks the first detailed multi-omic analysis of the HSM phase in Arabidopsis seedlings, providing insights into the multifaceted nature of this complex process. These comprehensive datasets hold promise in elucidating regulators of HS resilience, thereby enhancing efforts in breeding HS-tolerant crops

plant biology↗

bioRxiv2025

A field-focused systems approach reveals mRNA covalent modifications linked to sorghum growth and development under drought stress

RNA Covalent Modifications (RCMs) are post-transcriptional chemical alterations that influence RNA stability and translation efficiency, thus play critical roles in eukaryotic growth and development. However, their role in regulating plant performance under abiotic stress remain largely unexplored. Here, we integrated multi-omics data in six Sorghum bicolor accessions under water-limiting conditions in the field to explore the relationship between RCMs and drought response. Within a stress and photosynthesis-associated gene co-expression module, we identified SbDUS2, a member of family of enzymes, conserved across eukaryotes, which catalyzes the reduction of uracil to dihydrouridine (DHU) on RNA molecules. DHU-modified transcripts in this module were enriched for photosynthetic functions and showed strong correlation with photosynthetic traits. To elucidate the function of this RCM, we characterized loss of function dus2 mutants in the genetic model, Arabidopsis thaliana. Under control conditions, these DHU-deficient mutants exhibited impaired germination and delayed development. Furthermore, when exposed to heat or water-limiting conditions, these mutants showed significantly reduced net CO2 assimilation and survival. Using multiple transcriptome-wide RNA stability assays, we demonstrated that transcripts associated with lower DHU level in a dus2 background generally exhibited increased stability compared to Col-0 controls. Particularly, lack of DUS2 led to the hyperstability of photosynthesis-related transcripts, impeding their turnover and likely preventing proper photosynthetic acclimation during stress. We propose a model based on these data where DHU acts as a critical post-transcriptional regulator marking mRNAs for rapid turnover under stress, highlighting an overlooked regulatory layer contributing to plant resilience.

plant biology↗

bioRxiv2024

Small molecule oxybutynin rescues proliferative capacity of complex III-defective MPCs

Mitochondrial disease encompasses a group of genetically inherited disorders hallmarked by an inability of the respiratory chain to produce sufficient ATP. These disorders present with multisystemic pathologies that predominantly impact highly energetic tissues such as skeletal muscle. There is no cure or effective treatment for mitochondrial disease. We have discovered a small molecule known as oxybutynin that can bypass Complex III mitochondrial dysfunction in primary murine and human skeletal muscle progenitor cells (MPCs). Oxybutynin administration improves MPC proliferative capacity, enhances cellular glycolytic function, and improves myotube formation. Mechanistically, results from our isothermal shift assay indicates that oxybutynin interacts with a suite of proteins involved in mRNA processing which then trigger the upregulation biological pathways to circumvent CIII mitochondrial dysfunction. Taken together, we provide evidence for the small molecule oxybutynin as a potential therapeutic candidate for the future treatment of CIII mitochondrial dysfunction.

cell biology↗

bioRxiv2024

Identification of cell-type-specific response to silicon treatment in soybean leaves through single nucleus RNA-sequencing

In agriculture, mineral nutrients uptake and deposition profoundly influence plant development, stress resilience, and productivity. Despite its classification as a non-essential element, silicon (Si) is crucial in plant physiology, particularly in defense response and stress mitigation. While genetic and molecular mechanisms of Si uptake and transport are well-studied in monocots, particularly rice, its role in dicot species, such as soybean, remains unclear at the cellular and molecular levels. Traditional bulk transcriptomics methods lack the resolution to uncover cellular heterogeneity. Here, we present a study by utilizing single-nucleus RNA sequencing (snRNA-seq) to dissect cellular responses to Si accumulation in soybean leaves. Our analysis revealed distinct cellular populations, including a novel Si-induced cell cluster within vascular cells, suggesting a specific mechanism of Si distribution. Si treatment induced the expression of defense-related genes, particularly enriched in vascular cells, highlighting their specialized role in activating plant defense mechanisms. Moreover, Si modulated the expression of genes involved in RNA silencing, phytoalexin biosynthesis, and immune receptor signaling, suggesting a mechanism of transcriptional priming of genes involved in defense responses. We further investigated putative Si transporters, revealing differential expression patterns in response to Si treatment, suggesting presence of active and gradient-based transport mechanisms. Our findings shed light on the vital biotic stress regulatory networks governed by Si treatment in soybean leaves, paving potential strategies for enhancing stress tolerance and agronomic performance in crops.

plant biology↗

bioRxiv2024

The transcription factor ATML1 maintains giant cell identity by inducing synthesis of its own (very) long-chain fatty acid-containing ligands

During development, cells not only adopt specialized identities but also maintain those identities. Endoreduplication is thought to maintain cell identity. High concentrations of ARABIDOPSIS THALIANA MERISTEM LAYER1 (ATML1) specify giant cell identity and induce endoreduplication in sepals. How different concentrations of ATML1 can specify different identities remains unclear. Here, we show that high concentrations of ATML1 induce the biosynthesis of both long-chain and very long-chain fatty acids (LCFAs/VLCFAs), and these fatty acids are required for the maintenance of giant cell identity. Inhibition of VLCFA biosynthesis causes endoreduplicated giant cells to resume division and lose their identity, indicating that endoreduplication is not sufficient to maintain cell identity. Structural predictions suggest that LCFA-containing lipids bind to the START domain 2 of ATML1, causing ATML1 dimerization and its auto-activation. Our data and modeling imply that ATML1 induces biosynthesis of its own lipid ligands in a positive feedback loop, shedding light on the intricate network dynamics that specify and maintain giant cell identity. Teaser: Endoreduplicated cells in Arabidopsis thaliana sepals divide and de-differentiate in the absence of VLCFA biosynthesis.

plant biology↗

bioRxiv2024

Mapping protein-metabolite interactions in E. coli by integrating chromatographic techniques and co-fractionation mass spectrometry.

In our pursuit of understanding the protein-metabolite interactome, we introduced PROMIS, a co-fractionation mass spectrometry (CF-MS) technique focusing on biosynthetic and regulatory processes. However, the challenge lies in distinguishing true interactors from coincidental co-elution when a metabolite co-fractionates with numerous proteins. To address this, we integrated two chromatographic techniques-- size exclusion and ion exchange--to enhance the mapping of protein-metabolite interactions (PMIs) in Escherichia coli. This integration aims to refine the PMI network by considering size and charge characteristics, resulting in 994 interactions involving 51 metabolites and 465 proteins. The PMI network is enriched for known and predicted interactions validating our approachs efficacy. Furthermore, the analysis of protein targets for different metabolites revealed novel functional insights, such as the connection between proteinogenic dipeptides and fatty acid biosynthesis. Notably, we uncovered an inhibitory interaction between the riboflavin degradation product lumichrome and orotate phosphoribosyltransferase (PyrE), a key enzyme in de novo pyrimidine synthesis. Lumichrome supplementation mimicked the biofilm formation inhibition observed in a{Delta} pyrE mutant strain, suggesting lumichrome role in integrating pyrimidine and riboflavin metabolism with quorum sensing and biofilm formation. In summary, our integrated chromatographic approach significantly advances PMI mapping, offering novel insights into functional associations and potential regulatory mechanisms in E. coli.

biochemistry↗

bioRxiv2023

Characterization of tomato canal-1 mutant using a multi-omics approach

The recently described canal-1 tomato mutant, which has a variegated leaf phenotype, has been shown to affect canalization of yield. The corresponding protein is orthologous to AtSCO2 - SNOWY COTYLEDON2, which has suggested roles in thylakoid biogenesis. Here we characterize the canal-1 mutant through a multi-omics approach, by comparing mutant to wild-type tissues. While white canal-1 leaves are devoid of chlorophyll, green leaves of the mutant appear wild-type-like, despite an impaired protein function. Transcriptomic data suggest that green mutant leaves compensate for this impaired protein function by upregulation of transcription of photosystem assembly and photosystem component genes, thereby allowing adequate photosystem establishment, which is reflected in their wild-type-like proteome. White canal-1 leaves, however, likely fail to reach a certain threshold enabling this overcompensation, and plastids get trapped in an undeveloped state, while additionally suffering from high light stress, indicated by the overexpression of ELIP homolog genes. The metabolic profile of white and to a lesser degree also green tissues revealed upregulation of amino acid levels, that was at least partially mediated by transcriptional and proteomic upregulation. These combined changes are indicative of a stress response and suggest that white tissues behave as carbon sinks. In summary, our work demonstrates the relevance of the SCO2 protein in both photosystem assembly and as a consequence in the canalization of yield. Significance statementThe variegated canalized-1 tomato mutant was recently described and the underlying gene SCO2 suggested to be a yield canalization gene. Through a multi-omics approach we show that mutants require a transcriptional upregulation of photosystem components and assembly components, likely as overcompensation for partially impaired SCO2 function, to produce a wild type-like proteome and functional photosynthetic tissue Our data, furthermore, suggest that variation of green to white leaf area from plant to plant leads to the yield variation.

plant biology↗

bioRxiv2023

The genetic and physiological basis of Arabidopsis thaliana tolerance to Pseudomonas viridiflava

O_LIThe opportunistic pathogen Pseudomonas viridiflava colonizes more than fifty agricultural crop species and is the most common Pseudomonas in the phyllosphere of European Arabidopsis thaliana populations. Belonging to the P. syringae complex, it is genetically and phenotypically distinct from well-characterized P. syringae sensu stricto. Despite its prevalence, we lack knowledge of how A. thaliana responds to its native isolates at the molecular level. Here, we characterize the host response in an A. thaliana - P. viridiflava pathosystem. C_LIO_LIWe measured host and pathogen growth in axenic infections, and used immune mutants, transcriptomics, and metabolomics to determine defense pathways influencing susceptibility to P. viridiflava infection. C_LIO_LIInfection with P. viridiflava increased jasmonic acid (JA) levels and the expression of ethylene defense pathway marker genes. The immune response in a susceptible host accession was delayed compared to a tolerant one. Mechanical injury rescued susceptibility, consistent with an involvement of JA. C_LIO_LIThe JA/ethylene pathway is important for suppression of P. viridiflava, yet suppression capacity varies between accessions. Our results shed light on how A. thaliana can suppress the ever-present P. viridiflava, but further studies are needed to understand how P. viridiflava evades this suppression to spread broadly across A. thaliana populations. C_LI

plant biology↗

bioRxiv2022

The K+ exchange antiporter 3 senses the chloroplast energy status to synchronize photosynthesis

Plant photosynthesis contains two functional modules, the light-driven reactions in the thylakoid membrane and the carbon-fixing reactions in the chloroplast stroma. In nature, light availability for photosynthesis often undergoes massive and rapid fluctuations. Efficient and productive use of such variable light supply requires an instant crosstalk and rapid synchronization of both functional modules. Here, we show that this communication involves the stromal exposed regulatory C-terminus (RCT) of the thylakoid K+-exchange antiporter KEA3. RCT-mediated control of KEA3 contributes to the balance between light capture and photoprotection. By combining in silico, in vitro, and in vivo approaches, we demonstrate that the RCT senses the energy state of the chloroplast in form of both, phosphorylation and redox potential, in a pH-dependent manner and regulates KEA3 activity in response. Together our data pinpoint a regulatory feedback loop by which the stromal energy state orchestrates light capture and photoprotection via KEA3.

plant biology↗

bioRxiv2022

Comparative multi-omic analyses reveal gene regulatory networks controlling physiological and metabolic responses to drought in upland cotton

Drought stress substantially impacts crop physiology resulting in alteration of growth and productivity. Understanding the genetic and molecular crosstalk between stress responses and agronomically important traits such as fiber yield is particularly complicated in the allopolyploid species, upland cotton (Gossypium hirsutum), due to reduced sequence variability between A and D subgenomes. To better understand how drought stress impacts yield, the transcriptomes of 22 genetically and phenotypically diverse upland cotton accessions grown under well-watered and water-limited conditions in the Arizona low desert were sequenced. Gene co-expression analyses were performed, uncovering a group of stress response genes, in particular transcription factors GhDREB2A-A and GhHSFA6B-D, associated with improved yield under water-limited conditions in an ABA-independent manner. DNA affinity purification sequencing (DAP-seq), as well as public cistrome data from Arabidopsis, were used to identify targets of these two TFs. Among these targets were two lint-yield associated genes previously identified through genome-wide association studies (GWAS) -based approaches, GhABP-D and GhIPS1-A. Biochemical and phylogenetic approaches were used to determine that GhIPS1-A is positively regulated by GhHSFA6B-D, and that this regulatory mechanism is specific to Gossypium spp. containing the A (old-world) genome. Finally, a SNP was identified within the GhHSFA6B-D binding site in GhIPS1-A that is positively associated with yield under water limiting conditions. These data lay out a regulatory connection between abiotic stress and fiber yield in cotton that appears conserved in other systems such as Arabidopsis. This regulatory mechanism highlights how sub-genome dynamics contribute to phenotypic stress-response plasticity in cotton.

plant biology↗

bioRxiv2022

A novel role of 3,5-cAMP in the regulation of actin cytoskeleton in Arabidopsis.

The role of cyclic adenosine monophosphate (3,5-cAMP) in plants is not well understood, and here, we report a novel role of 3,5-cAMP in regulating the actin cytoskeleton. The 3,5-cAMP treatment affects the thermal stability of 51 proteins, including a vegetative actin isoform, ACTIN2. Consistent with the above results, the increase in 3,5-cAMP levels, obtained either by feeding or by chemical modulation of 3,5-cAMP metabolism, is sufficient to partially rescue the short hypocotyl phenotype of the actin2 actin7 mutant, severely compromised in actin level. No such complementation was measured for a positional isomer of 3,5-cAMP, 2,3-cAMP, attesting to the specificity of 3,5-cAMP treatment. Moreover, supplementation of 3,5-cAMP partly counters the activity of an actin-depolymerizing drug latrunculin B. In vitro characterization of the 3,5-cAMP - actin interaction argues against the direct binding. Instead, based on the proteomics characterization of the act2act7 mutant supplemented with 3,5-cAMP, we hypothesize that 3,5-cAMP affects cytoskeleton dynamic by modulation of calcium signaling, and actin binding proteins.

plant biology↗

bioRxiv2021

A ROS-Ca2+ signalling pathway identified from a chemical screen for modifiers of sugar-activated circadian gene expression.

Sugars are essential metabolites for energy and anabolism that can also act as signals to regulate plant physiology and development. Experimental tools to disrupt major sugar signalling pathways are limited. We have performed a chemical screen for modifiers of activation of circadian gene expression by sugars to discover pharmacological tools to investigate and manipulate plant sugar signalling. Using a library of commercially available bioactive compounds, we identified 75 confident hits that modified the response of a circadian luciferase reporter to sucrose in dark-adapted seedlings. We validated the transcriptional effect on a subset of the hits and measured their effects on a range of sugar-dependent phenotypes for 13 of these chemicals. Chemicals were identified that appear to influence known and unknown sugar signalling pathways. Pentamidine isethionate (PI) was identified as a modifier of a sugar-activated Ca2+ signal that acts downstream of superoxide in a metabolic signalling pathway affecting circadian rhythms, primary metabolism and plant growth. Our data provide a resource of new experimental tools to manipulate plant sugar signalling and identify novel components of these pathways.

plant biology↗

bioRxiv2021

Arabidopsis PROTODERMAL FACTOR2 binds lysophosphatidylcholines and transcriptionally regulates phospholipid metabolism

Plant homeodomain leucine-zipper IV (HD-Zip IV) transcription factors (TFs) contain an evolutionarily conserved steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domain. The START domain is required for TF activity; however, its presumed role as a lipid sensor is not well understood. Here we used tandem affinity purification from Arabidopsis cell cultures to demonstrate that PROTODERMAL FACTOR2 (PDF2), a representative family member which controls epidermal differentiation, recruits lysophosphatidylcholines in a START-dependent manner. In vitro assays with recombinant protein verified that a missense mutation in a predicted ligand contact site reduces lysophospholipid binding. We additionally uncovered that PDF2 controls the expression of phospholipid-related target genes by binding to a palindromic octamer with consensus to a phosphate (Pi) response element. Phospholipid homeostasis and elongation growth were altered in pdf2 mutants according to Pi availability. Cycloheximide chase experiments further revealed a role for START in maintaining protein levels, and Pi limitation resulted in enhanced protein destabilization, suggesting a mechanism by which lipid binding controls TF activity. We propose that the START domain serves as a molecular sensor for membrane phospholipid status in the epidermis. Overall our data provide insights towards understanding how the lipid metabolome integrates Pi availability with gene expression.

plant biology↗