Biology subjects

Martina, M.

Publications and source records attributed to Martina, M..

6 recordsLinked to original sources

bioRxiv2026

Genotype-dependent transcriptional trajectories during prolonged heat stress in Capsicum annuum L.

Heat stress is one of the most damaging abiotic constraints on crop productivity, and its consequences are expected to intensify as extreme temperature events become more frequent and severe. Pepper (Capsicum annuum L.) is particularly vulnerable to sustained high temperatures, which can disrupt photosynthetic performance, cellular homeostasis, and redox regulation. However, the physiological and transcriptional dynamics underlying genotype-dependent responses to prolonged heat exposure remain insufficiently understood. We combined repeated physiological measurements with time-course RNA sequencing to compare GPC003240, previously identified as a candidate heat-tolerant accession, with two non-elite accessions, GPC010350 and GPC014930, which are phenotypically divergent from each other, under 40/30 {degrees}C Day/night temperatures for up to six days. GPC010350 maintained comparatively stable photosystem II performance and higher stomatal conductance, whereas GPC014930 showed progressive photochemical impairment and lower conductance; GPC003240 displayed a distinct, moderately responsive profile. Transcriptomic responses showed partial functional convergence during the early phase of stress exposure but diverged markedly after six days. When gene expression at day 6 was compared with the pre-treatment baseline separately within each genotype, 4,436 differentially expressed genes were detected in GPC010350, compared with 680 in GPC003240 and only 78 in GPC014930. The late response of GPC010350 was associated with enrichment of RNA- and ribosome-related, biosynthetic, DNA-repair, and genome-maintenance functions. By contrast, GPC014930 showed negative enrichment of photosynthesis, plastid organization, redox homeostasis, and translation-related processes. Global co-expression analysis identified a time-decreasing photosynthesis-associated module (ME5) and two time-increasing modules, ME12 and ME19, that were enriched in genes contributing to the late GPC010350 response. Integration of differential expressions, module membership, and functional annotation highlighted a heat shock transcription factor (Caz03g27980), HSP101 (Caz03g07770), and a dual-specificity phosphatase (Caz05g20970) as candidates for further investigation. Overall, the results suggest that genotype-dependent responses to prolonged heat exposure were associated not only with the magnitude of early transcriptional change, but also with differences in the temporal organization of stress-response, maintenance, and metabolic processes. The contrasting responses of the non-elite accessions GPC010350 and GPC014930 further highlight the value of phenotypically diverse germplasm for uncovering mechanisms relevant to future heat-tolerance breeding.

plant biology↗

bioRxiv2026

A first pangenomic framework for globe artichoke supports SNP-based varietal fingerprinting

Globe artichoke (Cynara cardunculus var. scolymus L.) comprises a broad range of local ecotypes and varietal groups whose genetic diversity has been investigated through different molecular markers. However, recent advances in next-generation sequencing and pangenomics approaches provide new opportunities to capture genome-wide variation at higher resolution and to develop practical tools for varietal discrimination, traceability, and germplasm conservation. In this study, we developed the first pangenomic framework for cultivated artichoke and evaluated pangenome-informed SNP markers for varietal fingerprinting. Whole-genome resequencing data from the Italian local ecotype Asti Sori were integrated with publicly available genomic data from representative globe artichoke and cultivated cardoon accessions to construct and annotate a pangenome. Genome-wide SNP and presence/absence variation (PAV) analyses were combined with pangenome-anchored genotyping-by-sequencing (GBS) data from 45 accessions representing the main cultivated varietal groups. The pangenome revealed a largely conserved core gene repertoire alongside a smaller accessory component, with gene accumulation curves suggesting a tendency toward saturation within the sampled cultivated germplasm. SNP- and PAV-based analyses provided complementary views of accession relationships and consistently resolved the principal cultivated groups. Across the broader germplasm panel, pangenome-anchored GBS-derived SNPs identified well-supported phylogenetic clusters corresponding to recognized varietal types. A reduced panel of 50 SNPs, selected through iterative random subsampling, retained at least 90% of the genetic diversity captured by the full dataset and reproduced its main population structure. This compact pangenome-anchored marker set provides a practical foundation for varietal fingerprinting, DUS-oriented applications, traceability, and conservation of traditional globe artichoke germplasm. Validation across independent collections will be required before routine deployment.

Plant Biology↗

bioRxiv2026

Progressive drought transcriptomics and co-expression framework in eggplant (Solanum melongena L.)

Drought is a major constraint for eggplant productivity in Mediterranean and semi-arid environments, yet stage-specific molecular features that distinguish tolerant and sensitive genotypes under progressive water deficit remain limited. Here, we profiled drought responses in two contrasting eggplant (Solanum melongena L.) genotypes from the G2P-SOL core collection, integrating physiology and transcriptomics to resolve genotype-dependent programs at moderate and severe stress. Physiological measurements confirmed divergent drought performance, with the tolerant genotype Berenjena de rabo largo (GPE020510) maintaining water status and stomatal function longer than the sensitive genotype Qianzi (GPE008940). RNA-seq revealed strong transcriptional reprogramming in both genotypes, but with distinct timing and functional priorities across stress transitions. At moderate stress, tolerance was associated with early ABA-centred regulatory control and dehydration protection (including ABI5, TAS14 and LEA/dehydrin-related loci), coupled to transport and redox homeostasis and repression of growth-associated outputs. In contrast, the sensitive genotype showed prominent early regulatory and RNA/protein-turnover signatures alongside weaker representation of cuticle/barrier and chloroplast/light-management functions. Under severe stress, the sensitive genotype shifted toward a broad high-maintenance state enriched in remodeling, detoxification and transporter activity, whereas the tolerant genotype displayed a more targeted adjustment featuring plastid photoprotection, proteostasis and selective metabolic reconfiguration. Co-expression network analysis supported this stage-resolved model by identifying modules and hub genes with contrasting temporal trajectories between genotypes, linking earlier coordinated regulatory/membrane-trafficking and plastid/redox tuning to drought tolerance. Overall, these results indicate that eggplant drought resilience is associated with genotype-specific coordination and timing of protective programs superimposed on a shared basal stress response, and they provide prioritized candidate pathways and genes for functional validation and breeding.

plant biology↗

bioRxiv2026

PD-1-Dependent Modulation of Sensory Neurons by a Staphylococcus epidermidis Lipoteichoic Acid Drives Analgesia

BackgroundImmune checkpoint receptors regulate adaptive immunity but are increasingly recognized as modulators of neuroimmune interactions. The upstream signals that induce neuronal checkpoint pathways during inflammation and their functional relevance in inflammatory pain remain incompletely understood. We investigated whether a defined commensal-derived molecule engages a neuroimmune checkpoint axis to modulate inflammatory pain. MethodsSELTA, a lipoteichoic acid purified from a commensal Staphylococcus epidermidis strain, was evaluated for TLR2-dependent activity, regulation of Pdcd1 transcription and PD-1 protein expression in dorsal root ganglion (DRG) neurons, effects on intracellular calcium signaling, and behavioral outcomes in experimental autoimmune prostatitis (EAP) a model of inflammation-induced chronic pelvic pain. Conditional Pdcd1 deletion was performed in sensory neurons (Advillin-Cre) and CD4 T cells to determine cell-specific requirements. ResultsSELTA selectively activated TLR2/6 signaling and increased Pdcd1 transcription and PD-1 protein expression in DRG neurons under inflammatory conditions. SELTA enhanced phosphorylation of PD-1 at tyrosine 248 and significantly reduced ATP-evoked intracellular Ca{superscript 2} responses in mouse primary sensory neurons. Pharmacologic neutralization of PD-1 abrogated SELTA-mediated suppression of calcium signaling. In vivo, SELTA produced concentration-dependent attenuation of pelvic hypersensitivity in EAP. Conditional deletion of PD-1 in vivo in Advillin-expressing sensory neurons or CD4 T cells significantly reduced SELTA-induced analgesia, while combined deletion did not further diminish the effect. ConclusionsThese findings identify a commensal-derived lipoteichoic acid that engages a TLR2/6-associated pathway linked to inducible neuronal PD-1 signaling to restrain inflammatory nociceptor activity. The results define a neuroimmune checkpoint mechanism that modulates inflammatory pain and extend PD-1 signaling beyond its established role in adaptive immunity.

neuroscience↗

bioRxiv2026

Long-term salinity reveals genotype-specific transcriptional reprogramming in eggplant

Salinity severely limits eggplant productivity, yet the transcriptional bases of tolerance to prolonged salt exposure remain incompletely understood. Here, we analyzed long-term salinity responses in two contrasting eggplant (Solanum melongena L.) genotypes from the G2P-SOL core collection, focusing on genotype-dependent transcriptional regulation under chronic stress. Plants were exposed to 200 mM NaCl for 23 days at the reproductive stage, and transcriptome profiling was performed at the end of the stress period. Physiological assessment and high-throughput phenotyping confirmed a strong divergence in water status and plant architecture between genotypes under salinity, providing a reference framework for transcriptomic interpretation. RNA-seq analysis revealed marked genotype-specific differences in transcriptional responses. While both genotypes activated a conserved salt-stress program involving redox homeostasis, proteostasis and growth repression, the tolerant genotype displayed a substantially broader and more coordinated transcriptional reprogramming. This response involved large-scale modulation of pathways related to translation and RNA metabolism, hormone signaling crosstalk, membrane transport, cell wall remodeling and oxidative stress management, together with the selective repression of growth- and signaling-related functions. In contrast, the sensitive genotype showed a more limited response dominated by defense- and damage-associated transcripts. Overall, these results indicate that long-term salt tolerance in eggplant is associated with genotype-specific transcriptional reprogramming superimposed on a shared basal stress response. This work highlights regulatory pathways and candidate genes potentially relevant for breeding strategies targeting salt resilience.

plant biology↗

bioRxiv2018

Dorsal Hippocampal Activation Suppresses Neuropathic Pain Behaviors: Chronic pain as extinction-resistant pain-related memory traces

Accumulating evidence suggests the hippocampus being involved in, and modified with, chronic neuropathic pain. However, it is still not clear whether hippocampal activity has direct control over neuropathic behaviors. Here we show that activation of the dorsal, but not ventral, hippocampus, by glutamate microinjection or by chemogenetically increasing excitability (PSAM/PSEM), completely or partially reversed neuropathic behaviors: tactile allodynia and thermal hyperalgesia in the models of spared nerve injury and lumbar spinal nerve ligation. Using a new methodology (chemo-fMRI), where we combine awake resting state brain imaging with viral vector mediated chemogenetic activation (PSAM/PSEM), we could demonstrate that increased excitability of dorsal hippocampus neurons altered resting state functional connectivity within circuitry specifically related to the extent of diminution of neuropathic behavior (tactile allodynia). The identified circuitry most reliably (survived a validation procedure) identified dorsal hippocampal connections to the somatosensory cortex and the thalamus. Moreover, anterograde tracing indicated non-overlapping projections from dorsal and ventral hippocampus. Thus, the present study exhibits a novel causal role for the dorsal hippocampus, and mediating circuitry, controlling neuropathic pain-related behaviors. Altogether, these results imply downregulation of dorsal hippocampus circuitry in chronic neuropathic pain; the activation of which reverses pain behaviors either through disruption of accumulated memories and/or by enhancing extinction circuitry.

neuroscience↗