Biology subjects

Oliveira, M.

Publications and source records attributed to Oliveira, M..

At least 19 recordsLinked to original sources

bioRxiv2026

The activation of CT fibers or affective touch does not affect pain sensitization by secondary hyperalgesia

Interpersonal affective touch, that preferentially engages C-tactile (CT) afferents, has been shown to produce analgesic effects, yet its role in pain sensitization remains poorly understood. This study explores whether touch delivered at CT-optimal parameters--either artificial or interpersonal--modulates secondary hyperalgesia (SH) induced by high-frequency stimulation (HFS). Two experimental studies were conducted. In Study 1, 46 participants underwent SH induction during two conditions: robot stroking at CT-optimal velocities and vibrotactile stimulation. In Study 2, 64 participants (32 couples) experienced SH in two separate sessions: alone or accompanied by their partner delivering affective touch. Pain reports, electroencephalographic activity (N-P complex and time-frequency activity), electrocardiographic (ECG) and electrodermal activity data (EDA) were collected. HFS successfully established SH in both studies; however, no significant differences were found in the SH area between CT-stimulation and control conditions. In Study 2, partner-delivered affective touch significantly reduced reported acute pain during HFS compared to the alone condition, whereas no such effect was observed in Study 1 (robotic vs. vibrotactile). At the neural level, no condition effects were observed in the N-P complex, EEG time-frequency data and ECG indexes in either study. Tonic EDA after HFS was higher when participants received stroking from their romantic partner compared to being alone. No sex differences were observed. Overall, while affective touch from a romantic partner may reduce acute pain during nociceptive stimulation -an effect not observed with robotic CT-stimulation- neither robotic nor interpersonal affective touch appeared to modulate the development of secondary hyperalgesia.

neuroscience↗

bioRxiv2025

Effects of cell growth and temperature on mitochondrial physiology of Drosophila melanogaster embryonic cell line

The fruit fly Drosophila melanogaster is a valuable model for studying cellular and metabolic processes conserved with mammals. Using its embryonic Schneider S2 cell line, commonly used for heterologous protein expression, we investigated how culture duration and slight temperature changes affect mitochondrial physiology via high-resolution respirometry. We assessed five mitochondrial bioenergetic parameters and two coupling parameters at early and late growth phases, and at two temperatures (26{degrees}C and 28{degrees}C). We observed that a moderate temperature increase coupled with late growth phase synergistically enhanced basal, OXPHOS, and leak respiration, with only minor impacts on mitochondrial coupling efficiency. Notably, spare and maximal respiratory capacities increased disproportionately with either cell growth progression or moderate temperature rise, suggestive of enhanced mitochondrial biogenesis. These results demonstrate that small temperature increases and cell maturation activate mitochondrial bioenergetic capacity through mechanisms consistent with mitochondrial biogenesis and functional remodeling. Such adaptations improve cellular metabolic resilience while maintaining energy conversion efficiency. These findings deepen understanding of mitochondrial plasticity in response to environmental and developmental signals. They may inform strategies to optimize mitochondrial physiology in various biological contexts, including aging, metabolic diseases, and stress adaptation.

biochemistry↗

bioRxiv2025

Energy dissipation via the glycerol phosphate shuttle: coupling glycolysis to mitochondrial thermogenesis in Drosophila melanogaster flight muscle

Mitochondria are the central hubs of energy metabolism, integrating carbohydrate, lipid, and amino acid oxidation to produce ATP through the tricarboxylic acid cycle and oxidative phosphorylation. These organelles also regulate energy homeostasis via redox signaling and substrate exchange between cellular compartments. Mitochondrial redox shuttles maintain the balance between cytosolic and mitochondrial NAD(P)H pools by transferring reducing equivalents across membranes. Among these, the glycerol-phosphate shuttle (GPSh) connects glycolysis with mitochondrial oxygen consumption, regenerating cytosolic NAD+ while transferring electrons into the electron transport system. Although GPSh ensures continuous glycolytic flux, its lower energy yield may favor heat dissipation over ATP synthesis. In the present work, we investigated how substrate utilization shapes energy coupling and thermogenesis in Drosophila melanogaster flight muscle using chip calorimetry. Calorimetric assays revealed that G3P oxidation generated significantly more heat than complex I substrates, demonstrating its high thermogenic potential. When glucose was supplied to intact flight muscles, inhibition of the GPSh with iGP1 decreased heat generation by [~]85%, highlighting its importance for cytosolic NAD{square}turnover and glycolytic flux. In summary, GPSh serves as a key mechanism for sustaining NAD+ regeneration in glycolysis but operates with low energy efficiency, leading to increased heat production in highly metabolically active tissues such as insect flight muscle.

biochemistry↗

bioRxiv2025

The malate aspartate shuttle supports thermogenic lipid mobilization in brown adipocytes

Brown adipose tissue (BAT) plays a central role in thermogenesis by coupling fatty acid oxidation to heat production. Efficient BAT thermogenic activity requires enhanced glycolytic flux, which in turn depends on continuous regeneration of cytosolic NAD to sustain glyceraldehyde-3-phosphate dehydrogenase activity. This regeneration is mediated by three main pathways: lactate dehydrogenase, the glycerol-3-phosphate shuttle, and the malate-aspartate shuttle (MASh). We previously showed that inhibition of the mitochondrial pyruvate carrier increases energy expenditure in brown adipocytes via MASh activation. However, the specific contribution of MASh to BAT energy metabolism remains poorly defined. Here, we show that MASh is functional and directly regulates lipid metabolism in BAT. Enzymatic activities of cytosolic and mitochondrial malate dehydrogenases and glutamic-oxaloacetic transaminases in BAT were comparable to those in the liver. Using a reconstituted system of isolated BAT mitochondria and cytosolic MASh enzymes, we demonstrated that extra-mitochondrial NADH is efficiently reoxidized in a glutamate-dependent manner via MASh. Genetic silencing of the mitochondrial carriers critical to MASh--namely the oxoglutarate carrier (OGC1) and aspartate-glutamate carrier (Aralar1) had no apparent effects on respiratory rates. However, silencing either OGC1 or Aralar1 led to the accumulation of small lipid droplets and impaired norepinephrine-induced lipolysis. Taken together, our data indicate a novel role of MASh in regulating BAT lipid homeostasis with potential implications to body energy expenditure and thermogenesis.

biochemistry↗

bioRxiv2025

AID facilitates TET2 demethylation of Irf4 for plasma cell fate in germinal center B cells

Activation-induced cytidine deaminase (AID) is essential for B cell affinity maturation. We investigated why AID deficiency gives rise to giant germinal centers (GC) using the AIDR112H mouse model that is devoid of AID activity. The increased GC response was associated with accumulation of GC B cells in the light zone in immunized AIDR112H mice. AIDR112H GC B cells had reduced capacity to up-regulate IRF4 to initiate plasma cell differentiation, leading to accumulation of a transitional GC population with reduced GL7 expression. Genetic introduction of a high affinity B cell receptor (BCR) was unable to restore plasma cell differentiation of AIDR112H B cells while ectopic expression of catalytic active AID rescued plasma cell generation. AIDR112H impaired recruitment of AID to the Irf4 promoter/enhancer and disrupted the interaction with Ten-eleven Translocation 2 (TET2). Consequently, DNA demethylation at the Irf4 promoter/enhancer was reduced in AIDR112H GC B cells and impeded high Irf4 expression for transition into plasma cells. This data reveals a B cell-intrinsic mechanism that governs the plasma cell fate decision through epigenetic remodeling mediated by AID in cooperation with TET2. Key messagesO_LIAID deficiency leads to accumulation of a transitional (t)GC population of B cells with low expression of GL7 and failure to up-regulate IRF4 C_LIO_LIAID deamination activity is needed to promote up-regulation of IRF4 for plasma cell differentiation. C_LIO_LICo-operation between TET2 and AID facilitates demethylation of the Irf4 enhancer/promoter. C_LI

immunology↗

bioRxiv2024

Cardiolipin Inhibits the Noncanonical Inflammasome by Preventing LPS Binding to Caspase 4/11 to Mitigate Endotoxemia in Vivo

In Gram-negative bacterial sepsis, excessive caspase 4/11 activation in response to circulating bacterial lipid LPS (endotoxemia) can cause organ damage and mortality. Current inhibitors of caspase 4/11 also block caspase 1 activity and are therefore not appealing clinical candidates for treating Gram-negative sepsis. Here, we identify double-unsaturated 18:2 cardiolipin as a selective inhibitor of caspase 4/11-dependent inflammatory cytokine secretion and pyroptosis, without affecting caspase-1 responses. Cardiolipin targets the CARD domain of caspase 4/11, impeding its interaction with LPS to restrain caspase 4/11 activation, thereby suppressing endotoxemia-induced systemic inflammation in vivo. Thus, we present cardiolipin as a promising candidate for preventing endotoxemia- induced sequelae in sepsis while preserving caspase-1-driven anti-microbial immune responses. By identifying cardiolipin as a specific caspase 4/11 inhibitor, we provide an urgently-needed tool for studying caspase 4/11 functions in inflammatory pathways, and open the way to studies of noncanonical inflammasome regulation by endogenous cardiolipin.

immunology↗

bioRxiv2024

Targeting DNA-PK is a highly conserved poxvirus innate immune evasion mechanism

The sensing of viral nucleic acid by pattern recognition receptors (PRRs) is essential for initiation of a type-I interferon response against infection. Intracellular DNA sensing PRRs are responsible for initiating innate immune responses to poxviruses and other double-stranded DNA viruses. Poxviruses, in turn, encode an armoury of immunomodulators that inhibit this host defence mechanism. DNA-dependent protein kinase (DNA-PK) is an essential component of the cGAS/STING-dependent viral DNA sensing machinery that leads to the initiation of a type-I interferon response during poxvirus infection. Poxviruses counter this host sensing mechanism using the C4/C10 family of proteins that target DNA-PK, interfering with its ability to bind viral DNA. Although the DNA-PK complex, known also for its role in double strand break repair, is conserved across multiple taxa, its function in innate immunity outside mammals is unexplored. Here we analysed the contribution of DNA-PK to poxvirus DNA sensing in chickens, a species that is evolutionarily distant from mammals, but that is also infected by poxviruses. We found that DNA-PK functions as a DNA sensor in chickens, and this process is countered by C4/C10 family members found in fowlpox virus. This host/pathogen interaction is conserved across a broader range of species than other mechanisms of poxvirus antagonism of innate immune sensing, which may reflect the difficulty of the host in evolving escape mechanisms that interfere with a protein that is essential for maintenance of genomic stability.

immunology↗

bioRxiv2024

Spatial proteomics identifies a novel CRTC-dependent viral sensing pathway that stimulates production of Interleukin-11

Appropriate cellular recognition of viruses is essential for the generation of effective innate and adaptive antiviral immunity. Viral sensors and their signalling components thus provide a crucial first line of host defence. Many exhibit subcellular relocalisation upon activation, triggering expression of interferon and antiviral genes. To identify novel signalling factors we analysed protein relocalisation on a global scale during viral infection. CREB Regulated Transcription Coactivators-2 and 3 (CRTC2/3) exhibited early cytoplasmic-to-nuclear translocation upon a diversity of viral stimuli, in diverse cell types. This movement was depended on Mitochondrial Antiviral Signalling Protein (MAVS), cyclo-oxygenase proteins and protein kinase A. We identify a key effect of transcription stimulated by CRTC2/3 translocation as production of the pro-fibrogenic cytokine interleukin-11. This may be important clinically in viral infections associated with fibrosis, including SARS-CoV-2.

immunology↗

bioRxiv2023

Activation of innate immunity selectively compromises mitochondrial complex I, proline oxidation and flight activity in the major arbovirus vector Aedes aegypti

Aedes aegypti females are natural vectors of important arboviruses such as Dengue, Zika, and yellow fever. Mosquitoes activate innate immune response signaling pathways upon infection, as a resistance mechanism to fight pathogens and limit their propagation. Despite the beneficial effects of immune activation for insect vectors, phenotypic costs ultimately affect their fitness. However, the underlying mechanisms that mediate these fitness costs remain poorly understood. Given the high energy required to mount a proper immune response, we hypothesized that systemic activation of innate immunity would impair flight muscle mitochondrial function, compromising tissue energy demand and flight activity. Here, we investigated the dynamic effects of activation of innate immunity by intra-thoracic zymosan injection on A. aegypti flight muscle mitochondrial metabolism. Zymosan injection significantly increased defensin expression in fat bodies in a time-dependent manner that compromised flight activity. Although oxidant levels in flight muscle were hardly altered, ATP-linked respiratory rates driven by mitochondrial pyruvate+proline oxidation were significantly reduced at 24h upon zymosan injection. Oxidative phosphorylation coupling was preserved regardless of innate immune response activation along 24h. Importantly, rotenone-sensitive respiration and complex I-III activity were specifically reduced 24h upon zymosan injection. Also, loss of complex I activity compromised ATP-linked and maximal respiratory rates mediated by mitochondrial proline oxidation. Finally, the magnitude of innate immune response activation negatively correlated with respiratory rates, regardless of the metabolic states. Collectively, we demonstrate that activation of innate immunity is strongly associated with reduced flight muscle complex I activity with direct consequences to mitochondrial proline oxidation and flight activity. Remarkably, our results indicate a trade-off between dispersal and immunity exists in an insect vector, underscoring the potential consequences of disrupted flight muscle mitochondrial energy metabolism to arbovirus transmission.

biochemistry↗

bioRxiv2023

Mechanisms of type I interferon production by chicken TLR21

The innate immune response relies on the ability of host cells to rapidly detect and respond to microbial nucleic acids. Toll-like receptors (TLRs), a class of pattern recognition receptors (PRRs), play a fundamental role in distinguishing self from non-self at the molecular level. In this study, we focused on TLR21, an avian TLR that recognizes DNA motifs commonly found in bacterial genomic DNA, specifically unmethylated CpG motifs. TLR21 is believed to act as a functional homologue to mammalian TLR9. By analysing TLR21 signalling in chickens, we sought to elucidate avian TLR21 activation outputs in parallel to that of other nucleic acid species. Our analyses revealed that chicken TLR21 (chTLR21) triggers the activation of NF-{kappa}B and induces a potent type-I interferon response in chicken macrophages, similar to the signalling cascades observed in mammalian TLR9 activation. Notably, the transcription of interferon beta (IFNB) by chTLR21 was found to be dependent on both NF-{kappa}B and IRF7 signalling, but independent of the TBK1 kinase, a distinctive feature of mammalian TLR9 signalling. These findings highlight the conservation of critical signalling components and downstream responses between avian TLR21 and mammalian TLR9, despite their divergent evolutionary origins. These insights into the evolutionarily conserved mechanisms of nucleic acid sensing contribute to the broader understanding of host-pathogen interactions across species.

immunology↗

bioRxiv2023

Advancing GABA-edited MRS Research through a Reconstruction Challenge

PurposeTo create a benchmark for the comparison of machine learning-based Gamma-Aminobutyric Acid (GABA)-edited Magnetic Resonance Spectroscopy (MRS) reconstruction models using one quarter of the transients typically acquired during a complete scan. MethodsThe Edited-MRS reconstruction challenge had three tracks with the purpose of evaluating machine learning models trained to reconstruct simulated (Track 1), homogeneous in vivo (Track 2), and heterogeneous in vivo (Track 3) GABA-edited MRS data. Four quantitative metrics were used to evaluate the results: mean squared error (MSE), signal-to-noise ratio (SNR), linewidth, and a shape score metric that we proposed. Challenge participants were given three months to create, train and submit their models. Challenge organizers provided open access to a baseline U-NET model for initial comparison, as well as simulated data, in vivo data, and tutorials and guides for adding synthetic noise to the simulations. ResultsThe most successful approach for Track 1 simulated data was a covariance matrix convolutional neural network model, while for Track 2 and Track 3 in vivo data, a vision transformer model operating on a spectrogram representation of the data achieved the most success. Deep learning (DL) based reconstructions with reduced transients achieved equivalent or better SNR, linewidth and fit error as conventional reconstructions with the full amount of transients. However, some DL models also showed the ability to optimize the linewidth and SNR values without actually improving overall spectral quality, pointing to the need for more robust metrics. ConclusionThe edited-MRS reconstruction challenge showed that the top performing DL based edited-MRS reconstruction pipelines can obtain with a reduced number of transients equivalent metrics to conventional reconstruction pipelines using the full amount of transients. The proposed metric shape score was positively correlated with challenge track outcome indicating that it is well-suited to evaluate spectral quality.

bioengineering↗

bioRxiv2023

Heme exporter FLVCR regulates mitochondrial biogenesis and redox balance in the hematophagous insect Rhodnius prolixus

Heme is a prosthetic group of proteins involved in vital physiological processes in aerobic organisms. It participates in redox reactions crucial for cell metabolism due to the variable oxidation state of its central iron atom. However, excessive heme can be cytotoxic due to its prooxidant properties. Therefore, the control of intracellular heme levels ensures the survival of organisms, especially those that deal with high concentrations of heme during their lives, such as hematophagous insects. The feline leukemia virus C receptor (FLVCR) is a membrane protein responsible for heme transport in mammalian cells. In our study, we found that RpFLVCR serves as a heme exporter in the midgut of the hematophagous insect Rhodnius prolixus, a vector for Chagas disease. Silencing RpFLVCR decreased hemolymphatic heme levels and increased the levels of intracellular dicysteinyl-biliverdin, a product of R. prolixus heme degradation, indicating heme retention inside midgut cells. FLVCR silencing led to increased expression of heme oxygenase (HO), ferritin, and mitoferrin mRNAs while downregulating the iron importers Malvolio 1 and 2. In contrast, HO gene silencing increased FLVCR and Malvolio expression and downregulated ferritin, revealing crosstalk between heme degradation/export and iron transport/storage pathways. Furthermore, RpFLVCR silencing strongly increased oxidant production and lipid peroxidation, reduced cytochrome c oxidase activity and activated mitochondrial biogenesis, effects not observed in RpHO-silenced insects. These data support FLVCR function as a heme exporter, playing a pivotal role in heme/iron metabolism and maintenance of redox balance, especially in an organism adapted to face extremely high concentrations of heme.

biochemistry↗

bioRxiv2023

A Dual Color Pax7 and Myf5 In Vivo Reporter to Investigate Muscle Stem Cell Heterogeneity in Regeneration and Aging

Increasing evidence suggests heterogeneity in the muscle stem cell (MuSC) pool. In particular, a rare subset of Pax7 positive MuSCs that has never expressed the myogenic regulatory factor Myf5 has enhanced self-renewal and engraftment characteristics. However, the scarcity and limited availability of protein markers make the characterization of these cells challenging. We describe the generation of StemRep reporter mice allowing to monitor Pax7 and Myf5 protein based on equimolar levels of dual nuclear fluorescence. High levels of Pax7 protein and low levels of Myf5 delineate a deeply quiescent MuSC subpopulation with distinct molecular signatures and dynamics of activation, proliferation, and commitment. Aging decreases the number of these cells, and skews the MuSC pool towards Myf5-High cells with impaired quiescence. Altogether, we describe a novel deeply quiescent MuSC subpopulation whose maintenance is impaired in old muscles, and establish the StemRep line as a versatile tool to study quiescence and MuSC heterogeneity.

cell biology↗

bioRxiv2022

DNA-PKcs is required for cGAS/STING-dependent viral DNA sensing in human cells

To mount an efficient interferon response to virus infection, intracellular pattern recognition receptors (PRRs) sense viral nucleic acids and activate anti-viral gene transcription. The mechanisms by which intracellular DNA and DNA viruses are sensed are relevant not only to antiviral innate immunity, but also to autoinflammation and anti-tumour immunity through initiation of sterile inflammation by self-DNA recognition. The PRRs that directly sense and respond to viral or damaged self-DNA function by signalling to activate interferon regulatory factor (IRF)-dependent type one interferon (IFN-I) transcription. We and others have previously defined DNA-dependent protein kinase (DNA-PK) as an essential component of the DNA-dependent antiviral innate immune system. Here, we show that DNA-PK is essential for STING-dependent IFN-I responses in human cells during stimulation with exogenous DNA and infection with DNA viruses.

immunology↗

bioRxiv2022

Pharmacological activation of the mitochondrial stress protease OMA1 reveals a therapeutic liability in Diffuse Large B-Cell Lymphoma

Constitutive activation of the ATF4-mediated integrated stress response (ATF4-ISR) is common in cancer and buffers the metabolic challenges imposed by rapid proliferation. However, hyperactivation of the ISR can induce apoptosis. Here we demonstrate that novel pyrazolo-thiazole derivates activate the mitochondrial protease OMA1 which subsequently induces apoptosis in diffuse large B-cell lymphoma (DLBCL) cells. Apoptosis is dependent on the OMA1 mediated cleavage of DELE1 which leads to activation of HRI and induction of the ATF4 ISR. Screening in 406 cancer cell lines identified an inverse correlation between sensitivity to OMA1 activators and expression of the mitochondrial protein FAM210B. Ectopic overexpression of FAM210B specifically blocks OMA1 activation and apoptosis induction by pyrazolo-thiazole activators in DLBCL. OMA1 activators, including the preclinical candidate BTM-3566, selectively killed ABC, GCB, and double-hit DLBCL lines and induced complete tumor regression across a panel of DLBCL patient-derived xenografts. SignificanceHere we describe a novel class of small molecules that activate the mitochondrial protease OMA1 and induce therapeutic responses in DLBCL preclinical models in vitro and in vivo. OMA1 activation drives apoptosis through ATF4-ISR, an orthogonal mechanism to current therapies.

cancer biology↗

bioRxiv2022

LUBAC is required for RIG-I sensing of RNA viruses

The ability of cells to mount an interferon response to virus infections depends on intracellular nucleic acid sensing pattern recognition receptors (PRRs). RIG-I is an intracellular PRR that binds short double stranded viral RNAs to trigger MAVS-dependent signalling. The RIG-I/MAVS signalling complex requires the coordinated activity of multiple kinases and E3 ubiquitin ligases to activate the transcription factors that drive type I and type III interferon production from infected cells. The linear ubiquitin chain assembly complex (LUBAC) regulates the activity of multiple receptor signalling pathways in both ligase-dependent and -independent ways. Here, we show that the three proteins that constitute LUBAC have separate functions in regulating RIG-I signalling. Both HOIP, the E3 ligase capable of generating M1-ubiquitin chains, and LUBAC accessory protein HOIL-1 are required for viral RNA sensing by RIG-I. The third LUBAC component, SHARPIN, is not required for RIG-I signalling. These data cement the role of LUBAC as a positive regulator of RIG-I signalling and as an important component of antiviral innate immune responses.

immunology↗

bioRxiv2021

ROS/RNS balancing, aerobic fermentation regulation and cell cycle control a complex early trait ('CoV-MAC-TED') for combating SARS-CoV-2-induced cell reprogramming

In a perspective entitled From plant survival under severe stress to anti-viral human defense we raised and justified the hypothesis that transcript level profiles of justified target genes established from in vitro somatic embryogenesis (SE) induction in plants as a reference compared to virus-induced profiles can identify differential virus signatures that link to harmful reprogramming. A standard profile of selected genes named ReprogVirus was proposed for in vitro-scanning of early virus-induced reprogramming in critical primary infected cells/tissues as target trait. For data collection, the ReprogVirus platform was initiated. This initiative aims to identify in a common effort across scientific boundaries critical virus footprints from diverse virus origins and variants as a basis for anti-viral strategy design. This approach is open for validation and extension. In the present study, we initiated validation by experimental transcriptome data available in public domain combined with advancing plant wet lab research. We compared plant-adapted transcriptomes according to RegroVirus complemented by alternative oxidase (AOX) genes during de novo programming under SE-inducing conditions with in vitro corona virus-induced transcriptome profiles. This approach enabled identifying a major complex trait for early de novo programming during SARS-CoV-2 infection, called CoV-MAC-TED. It consists of unbalanced ROS/RNS levels, which are connected to increased aerobic fermentation that links to alpha-tubulin-based cell restructuration and progression of cell cycle. We conclude that anti-viral/anti-SARS-CoV-2 strategies need to rigorously target CoV-MAC-TED in primary infected nose and mouth cells through prophylactic and very early therapeutic strategies. We also discuss potential strategies in the view of the beneficial role of AOX for resilient behavior in plants. Furthermore, following the general observation that ROS/RNS equilibration/redox homeostasis is of utmost importance at the very beginning of viral infection, we highlight that de-stressing disease and social handling should be seen as essential part of anti-viral/anti-SARS-CoV-2 strategies.

cell biology↗

bioRxiv2021

Adaptive reprogramming during early seed germination requires temporarily enhanced fermentation a critical role for alternative oxidase (AOX) regulation that concerns also microbiota effectiveness

Plants respond to environmental cues via adaptive cell reprogramming that can affect whole plant and ecosystem functionality. Microbiota constitutes part of plants inner and outer environment. This Umwelt underlies steady dynamics, due to complex local and global biotic and abiotic changes. Hence, adaptive plant holobiont responses are crucial for continuous metabolic adjustment at systems levels. Plants require oxygen-dependent respiration for energy-dependent adaptive morphology, such as, germination, root and shoot growth, formation of adventitious, clonal and reproductive organs, fruits and seeds. Fermentative paths can help in acclimation and, to our view the role of alternative oxidase (AOX) in coordinating complex metabolic and physiologic adjustments is underestimated. Cellular level of sucrose is an important sensor of environmental stress. We explored the role of exogenous sucrose and its interplay with AOX during early seed germination. We found that sucrose-dependent initiation of fermentation during the first 12 hours after imbibition (HAI) was beneficial to germination. However, parallel enhanced AOX expression was essential to control negative effects by prolonged sucrose treatment. Early down-regulated AOX activity until 12 HAI improved germination efficiency in the absence of sucrose, but suppressed early germination in its presence. Our results also suggest that seeds-inoculated arbuscular mycorrhizal fungi can buffer sucrose stress during germination to restore normal respiration more efficiently. Following this approach, we propose a simple method to identify organic seeds and low-cost on-farm perspectives for early selection on disease tolerance, predicting plant holobiont behavior and improving germination. Furthermore, our research strengthens the view that AOX can serve as powerful functional marker source for seed hologenomes.

cell biology↗