Early Stress Research Articles

Drug-resilient Cancer Cell Phenotype Is Acquired via Polyploidization Associated with Early Stress Response Coupled to HIF2α Transcriptional Regulation.

In response to cisplatin treatment, some surviving cancer cells undergo whole-genome duplications without mitosis, which represents a mechanism of drug resistance. This study presents mechanistic data to implicate AP-1 and HIF2α signaling in the formation of this surviving cell phenotype. The results open a new avenue for targeting drug-resistant cells.

Assessing corn recovery from early season nutrient stress under different soil moisture regimes.

Corn (Zea mays) biomass accumulation and nutrient uptake by the six-leaf collar (V6) growth stage are low, and therefore, synchronizing nutrient supply with crop demand could potentially minimize nutrient loss and improve nutrient use efficiency. Knowledge of corn's response to nutrient stress in the early growth stages could inform such nutrient management. Field studies were conducted to assess corn recovery from when no fertilizer application is made until the V6 growth stage, and thereafter, applying fertilizer rates as those in non-stressed conditions. The early season nutrient stress and non-stress conditions received the same amount of nutrients. As the availability of nutrients for plant uptake is largely dependent on soil moisture, corn recovery from the early season nutrient stress was assessed under different soil moisture regimes induced via irrigation scheduling at 50% and 80% field capacity under overhead and subsurface drip irrigation (SSDI) systems. Peanut (Arachis hypogaea) was the previous crop under all conditions, and the fields were under cereal rye (Secale cereale) cover crop prior to planting corn. At the V6 growth stage, the nutrient concentrations of the early season-stressed crops, except for copper, were above the minimum threshold of sufficiency ranges reported for corn. However, the crops showed poor growth, with biomass accumulation being reduced by over 50% compared to non-stressed crops. Also, the uptake of all nutrients was significantly lower under the early season nutrient stress conditions. The recovery of corn from the early season nutrient stress was low. Compared to non-stress conditions, the early season nutrient stress caused 1.58 Mg ha-1 to 3.4 Mg ha-1 yield reduction. The percent yield reduction under the SSDI system was 37.6-38.2% and that under the overhead irrigation system was 11.7-13%. The high yield reduction from the early season nutrient stress under the SSDI system was because of water stress conditions in the topsoil soil layer. The findings of the study suggest ample nutrient supply in the early season growth stage is critical for corn production, and thus, further studies are recommended to determine the optimum nutrient supply for corn at the initial growth stages.

Early developmental carry-over effects on exploratory behaviour and DNA methylation in wild great tits (Parus major).

Adverse, postnatal conditions experienced during development are known to induce lingering effects on morphology, behaviour, reproduction and survival. Despite the importance of early developmental stress for shaping the adult phenotype, it is largely unknown which molecular mechanisms allow for the induction and maintenance of such phenotypic effects once the early environmental conditions are released. Here we aimed to investigate whether lasting early developmental phenotypic changes are associated with post-developmental DNA methylation changes. We used a cross-foster and brood size experiment in great tit (Parus major) nestlings, which induced post-fledging effects on biometric measures and exploratory behaviour, a validated personality trait. We investigated whether these post-fledging effects are associated with DNA methylation levels of CpG sites in erythrocyte DNA. Individuals raised in enlarged broods caught up on their developmental delay after reaching independence and became more explorative as days since fledging passed, while the exploratory scores of individuals that were raised in reduced broods remained stable. Although we previously found that brood enlargement hardly affected the pre-fledging methylation levels, we found 420 CpG sites that were differentially methylated between fledged individuals that were raised in small versus large sized broods. A considerable number of the affected CpG sites were located in or near genes involved in metabolism, growth, behaviour and cognition. Since the biological functions of these genes line up with the observed post-fledging phenotypic effects of brood size, our results suggest that DNA methylation provides organisms the opportunity to modulate their condition once the environmental conditions allow it. In conclusion, this study shows that nutritional stress imposed by enlarged brood size during early development associates with variation in DNA methylation later in life. We propose that treatment-associated DNA methylation differences may arise in relation to pre- or post-fledging phenotypic changes, rather than that they are directly induced by the environment during early development.

Spatiotemporal metabolic responses to water deficit stress in distinct leaf cell-types of poplar.

The impact of water-deficit (WD) stress on plant metabolism has been predominantly studied at the whole tissue level. However, plant tissues are made of several distinct cell types with unique and differentiated functions, which limits whole tissue 'omics'-based studies to determine only an averaged molecular signature arising from multiple cell types. Advancements in spatial omics technologies provide an opportunity to understand the molecular mechanisms underlying plant responses to WD stress at distinct cell-type levels. Here, we studied the spatiotemporal metabolic responses of two poplar (Populus tremula× P. alba) leaf cell types -palisade and vascular cells- to WD stress using matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI). We identified unique WD stress-mediated metabolic shifts in each leaf cell type when exposed to early and prolonged WD stresses and recovery from stress. During water-limited conditions, flavonoids and phenolic metabolites were exclusively accumulated in leaf palisade cells. However, vascular cells mainly accumulated sugars and fatty acids during stress and recovery conditions, respectively, highlighting the functional divergence of leaf cell types in response to WD stress. By comparing our MALDI-MSI metabolic data with whole leaf tissue gas chromatography-mass spectrometry (GC-MS)-based metabolic profile, we identified only a few metabolites including monosaccharides, hexose phosphates, and palmitic acid that showed a similar accumulation trend at both cell-type and whole leaf tissue levels. Overall, this work highlights the potential of the MSI approach to complement the whole tissue-based metabolomics techniques and provides a novel spatiotemporal understanding of plant metabolic responses to WD stress. This will help engineer specific metabolic pathways at a cellular level in strategic perennial trees like poplars to help withstand future aberrations in environmental conditions and to increase bioenergy sustainability.

Early exposure to maternal stress and risk for atopic dermatitis in children: A systematic review and meta-analysis.

The incidence of atopic dermatitis (AD) in children is increasing. Early exposure to stress factors may be associated with the AD development. This study aimed to summarize studies that reported an association between stress exposure and AD development in later life. A comprehensive literature search was performed using online databases (PubMed, EMBASE, PsycINFO, and Web of Science) for articles published up to May 1, 2023. Eligible studies were screened and selected based on the inclusion criteria. We incorporated cohort or case-control studies published in English which explored the relationship between stress experienced by parents or children and AD. The pooled odds ratio (OR) was calculated according to the type of stress using a random-effects model. Twenty-two studies were included. AD was related to maternal distress (OR 1.29, 95% Confidence Interval [CI]: 1.13-1.47), maternal anxiety (OR 1.31, 95% CI: 1.18-1.46), and negative life events (OR 2.00, 95% CI: 1.46-2.76). Maternal depression during pregnancy was associated with AD (OR 1.21, 95% CI: 1.09-1.33), whereas no significant association was found for postpartum depression. Research on stress experienced by paternal or children is scare. Early maternal stress may potentially elevate the risk of AD in their offspring. Importantly, rigorously designed studies are required to corroborate the link between maternal stress and AD in children. These studies should aim to gather insights about the impact of stress during specific trimesters of pregnancy, postnatal stress, and paternal stress, and to identify potential prevention strategies.

The role of parental divorce in the later vulnerability to perinatal depression and early parenting stress.

This study will examine the role of childhood experience of parental divorce on later perinatal depression and parenting stress. 546 women were recruited at less than 20weeks pregnancy into an ongoing pregnancy cohort study and followed up in pregnancy and the postpartum. Depression at recruitment was measured using the Structured Clinical Interview for the DSM and the Edinburgh Postnatal Depression Scale repeated in pregnancy and the postpartum. Parenting stress was measured at 12months postpartum using Parenting Stress Index. This study found 33% of women had experienced parental divorce. While we did not find a statistically significant relationship between the experience of parental divorce and perinatal depression, there was a higher rate of perinatal depression when parental divorce occured at a younger age. There was no association with parental divorce and parenting stress. Childhood divorce was significantly associated with other adverse childhood experiences. Our findings did not support an impact of parental divorce on either maternal perinatal depression or on parenting stress, suggesting the experience of parental divorce for children may not inevitably impact their later experiences as parents. Further research on the association with age of parental divorce and later perinatal mental health is warranted.

The crosstalk between photoperiod and early mild stress on juvenile oscar (Astronotus ocellatus) after acute stress.

Early mild stress (EMS) is like preparedness and might help fish deal with stress appropriately. This study investigated how EMS and photoperiod changes can impact growth, haematology, blood biochemistry, immunological response, antioxidant system, liver enzymes, and stress response of oscar (Astronotus ocellatus; 7.29 ± 0.96 g) before and after acute confinement stress (AC stress). Ten experimental treatments included five different photoperiods 8L16D (08:16 light to dark), 12L12D (12:12 light to dark), 16L8D (16:08 light to dark), 20L4D (20:04 light to dark), and 24L0D (24:00 light to dark), and these five photoperiod schedules were conducted in an EMS condition. After 9 weeks, no significant differences were found in growth parameters, survival rate, and body composition. At the end of the experiment and after AC stress, fish farmed in 24 light hours had the lowest haematocrit, white blood cells, total protein, blood performance, lysozyme, immunoglobulin M, complement C3, superoxide dismutase, and catalase. Fish that experienced EMS had significantly higher survival rates than those farmed in normal conditions (80.67% vs 61.33%). In conclusion, considering all measured parameters, 8-h light can be suggested as an optimum photoperiod for this fish species. Under 24L0D (no EMS) conditions, there were many negative effects apparent. In addition, a positive effect of EMS was evident in terms of survival after AC stress. AC stress decreased some health parameters under 24-h light treatment, while these results were not observed in EMS-exposed fish. Therefore, the EMS schedule can be a useful tool in preventing the negative effects of stress.

Ultrasmall ruthenium nanozyme with RONS scavenging and anti-inflammatory effects for effective prevention of postoperative peritoneal adhesion

Postoperative peritoneal adhesion is one of the most common complications after abdominal and pelvic surgery. Early inflammatory response and oxidative stress induced by peritoneal injury play important roles in adhesion formation. However, current research mainly focuses on developing barrier materials to physically separate injury sites for preventing peritoneal adhesions, but often ignores the pathologic changes promoting adhesion formation, resulting in unsatisfactory outcomes. Herein we report a versatile nanozyme (ultrasmall ruthenium nanoparticles, RuNPs) with great antioxidant and anti-inflammatory effects targeting the intrinsic causes of peritoneal adhesions. RuNPs sufficiently protect mesothelial cells from oxidative stress by scavenging reactive species and suppress inflammatory response via NF-κB pathway blockade. In rats with cecum abrasion-abdominal wall defect, RuNPs alone or combined with barrier material effectively prevent adhesion formation and promote injured tissue healing through alleviating oxidative stress and inflammation. This study not only generates a promising nano-agent for preventing adhesions but also provides a novel therapeutic strategy by targeting the underlying causation of adhesion formation.

AI-assisted image analysis and physiological validation for progressive drought detection in a diverse panel of Gossypium hirsutum L.

Drought detection, spanning from early stress to severe conditions, plays a crucial role in maintaining productivity, facilitating recovery, and preventing plant mortality. While handheld thermal cameras have been widely employed to track changes in leaf water content and stomatal conductance, research on thermal image classification remains limited due mainly to low resolution and blurry images produced by handheld cameras. In this study, we introduce a computer vision pipeline to enhance the significance of leaf-level thermal images across 27 distinct cotton genotypes cultivated in a greenhouse under progressive drought conditions. Our approach involved employing a customized software pipeline to process raw thermal images, generating leaf masks, and extracting a range of statistically relevant thermal features (e.g., min and max temperature, median value, quartiles, etc.). These features were then utilized to develop machine learning algorithms capable of assessing leaf hydration status and distinguishing between well-watered (WW) and dry-down (DD) conditions. Two different classifiers were trained to predict the plant treatment-random forest and multilayer perceptron neural networks-finding 75% and 78% accuracy in the treatment prediction, respectively. Furthermore, we evaluated the predicted versus true labels based on classic physiological indicators of drought in plants, including volumetric soil water content, leaf water potential, and chlorophyll a fluorescence, to provide more insights and possible explanations about the classification outputs. Interestingly, mislabeled leaves mostly exhibited notable responses in fluorescence, water uptake from the soil, and/or leaf hydration status. Our findings emphasize the potential of AI-assisted thermal image analysis in enhancing the informative value of common heterogeneous datasets for drought detection. This application suggests widening the experimental settings to be used with deep learning models, designing future investigations into the genotypic variation in plant drought response and potential optimization of water management in agricultural settings.

Phenotypic variability for early drought stress resistance in tetraploid wheat accessions correlates with terminal drought performance

AbstractDurum wheat (Triticum durum Desf.) is a fundamental staple food for the countries of the Mediterranean basin. Climate change is predicted to cause a trend of increasing drought severity in this region in the near future, necessitating the improvement of durum wheat's resilience to drought stress. Using polyethylene glycol to simulate water scarcity, early vigour parameters in germinating seeds are quickly, easily and affordably assessed. Many screenings, however, only consider the seedling stage; consequently, genotypes identified as promising for cultivation in drought scenarios, may not show such features if drought appears in later phenological phases, as happens in Mediterranean climatic areas, generally prone to terminal drought. The correlation between drought stress resistance during the seedling stage (early vigour) and later stages in the life cycle is elusive due to the lack of scientific efforts. Here we used polyethylene glycol screening to classify fifty‐five tetraploid wheat accessions into three clusters (susceptible, medium resistant and highly resistant to drought), based on morpho‐physiological traits. These accessions included durum wheat cultivars and landraces, as well as ancestors like durum emmer wheat and wild emmer wheat. The results of the screenings were combined with subsequent pot experiments using nine randomly selected accessions, imposing terminal drought, and evaluating their performance. Principal component analysis was performed on data for net photosynthesis, stomatal conductance, transpiration and grain yield. Notably, the genotypes that performed best in the pot experiments were also those that performed well in the screening. Highly resistant candidates had in fact higher physiological and performance parameters than susceptible candidates. In summary, polyethylene glycol screening of germinating seeds resulted to be suitable to predictively evaluate drought resistance in tetraploid wheat accessions under terminal drought conditions, typical of Mediterranean climate zones. The reported data, thus evidence of how this inexpensive and simple method might be efficiently applied for large‐scale phenotyping.

Role of cluster structure on the deformation behavior of Zr58Cu36Al6 metallic glass

Molecular dynamics simulations were used to simulate the process of tensile and compressive deformation of Zr58Cu36Al6 metallic glass (MG), and the variations of various cluster structures during the deformation were analyzed by the Voronoi tessellation method. The prepared Zr58Cu36Al6 alloy was found to be amorphous and the glass transition temperature obtained was about 753 K. In the deformation processes, the icosahedral-like clusters with the biggest quantity percentage decreased significantly and eventually, the damaged icosahedral-like clusters tended to be destroyed into "fragmented" clusters. Icosahedral-like clusters were more stable due to their lower average strain and shear stress compared to other clusters. The higher strain and shear stress of the clusters led to an earlier stress drop of Zr58Cu36Al6 MG during compression. However, the higher connectivity of the icosahedral network remained in Zr58Cu36Al6 MG making the overshoot stress and flow stress larger but lower plasticity in compression than those in tension.

The role of priming and memory in rice environmental stress adaptation: Current knowledge and perspectives.

Plant responses to abiotic stresses are dynamic, following the unpredictable changes of physical environmental parameters such as temperature, water and nutrients. Physiological and phenotypical responses to stress are intercalated by periods of recovery. An earlier stress can be remembered as 'stress memory' to mount a response within a generation or transgenerationally. The 'stress priming' phenomenon allows plants to respond quickly and more robustly to stressors to increase survival, and therefore has significant implications for agriculture. Although evidence for stress memory in various plant species is accumulating, understanding of the mechanisms implicated, especially for crops of agricultural interest, is in its infancy. Rice is a major food crop which is susceptible to abiotic stresses causing constraints on its cultivation and yield globally. Advancing the understanding of the stress response network will thus have a significant impact on rice sustainable production and global food security in the face of climate change. Therefore, this review highlights the effects of priming on rice abiotic stress tolerance and focuses on specific aspects of stress memory, its perpetuation and its regulation at epigenetic, transcriptional, metabolic as well as physiological levels. The open questions and future directions in this exciting research field are also laid out.

Adverse childhood experiences differently affect Theory of Mind brain networks in schizophrenia and healthy controls

Patients with schizophrenia (SZ) show impairments in both affective and cognitive dimensions of theory of mind (ToM). SZ are also particularly vulnerable to detrimental effect of adverse childhood experiences (ACE), influencing the overall course of the disorder and fostering poor social functioning. ACE associate with long-lasting detrimental effects on brain structure, function, and connectivity in regions involved in ToM. Here, we investigated whether ToM networks are differentially affected by ACEs in healthy controls (HC) and SZ, and if these effects can predict the disorder clinical outcome. 26 HC and 33 SZ performed a ToM task during an fMRI session. Whole-brain functional response and connectivity (FC) were extracted, investigating the interaction between ACEs and diagnosis. FC values significantly affected by ACEs were entered in a cross-validated LASSO regression predicting Positive and Negative Syndrome Scale (PANSS), Interpersonal Reactivity Index (IRI), and task performance. ACEs and diagnosis showed a widespread interaction at both affective and cognitive tasks, including connectivity between vmPFC, ACC, precentral and postcentral gyri, insula, PCC, precuneus, parahippocampal gyrus, temporal pole, thalamus, and cerebellum, and functional response in the ACC, thalamus, parahippocampal gyrus and putamen. FC predicted the PANSS score, the fantasy dimension of IRI, and the AToM response latency. Our results highlight the crucial role of early stress in differentially shaping ToM related brain networks in HC and SZ. These effects can also partially explain the clinical and behavioral outcomes of the disorder, extending our knowledge of the effects of ACEs.

Overexpression of MiSPL3a and MiSPL3b confers early flowering and stress tolerance in Arabidopsis thaliana

SQUAMOSA promoter-binding protein-like (SPL) family genes play an important role in regulating plant flowering and resistance to stress. However, understanding the function of the SPL family in mango is still limited. In a previous study, two MiSPL3 genes, MiSPL3a and MiSPL3b (MiSPL3a/b), were identified in ‘SiJiMi’ mango and exhibited the highest expression in flowers at the initial flowering stage [24]. Therefore, in this study, we further investigated the expression pattern and gene function of MiSPL3a/b. The results showed that the expression of MiSPL3a was greatest at the end of floral bud differentiation, and MiSPL3b was expressed mainly during the flowering induction and vegetative growth stages. Subcellular localization showed that MiSPL3a/b localized to the nucleus. In addition, ectopic expression of MiSPL3a/b promoted earlier flowering in Arabidopsis thaliana by 3 d-6 d than in wild-type (WT) plants, which increased the expression of SUPPRESSOR OF CONSTANS1 (AtSOC1), FRUITFULL (AtFUL), and APETALA1 (AtAP1). MiSPL3a/b transgenic lines exhibited increased tolerance to drought, GA3, and abscisic acid (ABA) treatments but were sensitive to Pro-Ca treatment. Furthermore, protein interaction analysis revealed that MiSPL3a/b could interact with several stress-related proteins, flowering-related proteins, and the bridge protein 14–3-3. Taken together, MiSPL3a and MiSPL3b acted as positive regulators of flowering time and stress tolerance in transgenic Arabidopsis.

High urine sodium/potassium ratio, high LDL/HDL ratio, high level of serum F2-isoprostane, and low level of microtubule-associated protein 1a/1b-light chain 3b (LC3B) as risk factors of preeclampsia

Background: Preeclampsia (PE), still a major health concern which is related to high maternal mortality and morbidity rates. It is historically correlated with early oxidative stress and autophagy dysfunction, prompting this study to investigate the potential risk factors of PE, including high level of urine sodium/potassium (Na/K) ratio, low-density lipoprotein to high-density lipoprotein (LDL/HDL) ratio, elevated serum F2-Isoprostane levels (F2-IsoPS), and diminished serum microtubule-associated protein 1a/1b-light chain 3b (LC3B). Methods: This is a case-control study, conducted at Prof. Dr. I.G.N.G Ngoerah General Hospital from June to September 2023, including 25 pregnant women with preeclampsia (PE) as cases and 25 without PE as controls. The study analyses urine sodium and potassium levels, serum LDL and HDL levels, LC3B, and F2-isoprostane levels using the Enzyme-linked Immunoassay (ELISA) method. Statistical analysis was conducted using IBM SPSS Statistics Version 25 software. Results: High urine sodium/potassium ratio (>3.95), high serum LDL/HDL Ratio (>2.6), high serum F2-Isoprostane levels (>476.24 ng/mL), and low serum LC3B levels (<291.975 ng.mL) was found to be a significant risk factor for preeclampsia, with an OR of 11.16 (p < 0.001; 95% CI = 2.86 – 43.46); OR= 23.222 (p < 0.001; 95% CI = 5.101 – 105.728); OR= 38.5 (p=0.000; 95% CI: 7.681-192.985); and OR=8.143 (p=0.001; 95% CI: 2.294-28.901) respectively. Based on multivariate analysis, the variables that contribute mainly to the occurrence of PE, from the highest, respectively, are high LDL/HDL ratio, high level of F2-IsoPs, low level of serum LC3B, and high urine Na/K ratio (OR=149.96; OR=95.43; OR=36.11; and OR=12.71). Conclusion: High LDL/HDL ratio, high level of F2-Isoprostanes serum, low level of serum LC3B, and high urine Na/K ratio are risk factors for preeclampsia.

Abstract WMP31: Lifetime Trauma Exposure Types Are Linked to Stroke Recovery: Findings From the STRONG Study

Introduction: The STRONG (Stroke, sTress, RehabilitatiON, and Genetics) study has documented the role of cumulative lifetime stress/trauma exposure (LSE) in stroke recovery. Understanding the types of trauma most closely linked with functional outcomes may identify specific risk factors for stroke recovery. We examined specific types of life stress linked with functional and cognitive disability at 1-year post-stroke. Methods: Adults with a new stroke enrolled at 28 US sites were assessed 4 times over 1 year. Assessments included LSE 90 days post-stroke, and Stroke Impact Scale (SIS), modified Rankin Scale (mRS), & Telephone Montreal Cognitive Assessment (tMOCA) at 1-year post-stroke. Bivariate and multivariate analyses examined relationships among LSE and outcomes. Results: The 763 enrollees had age 63.1±14.9 yrs; initial NIHSS score 4 [2-9]; 41.2% Female; 69.4% White. Controlling for age, gender, race, and 3-mo NIHSS score, lifetime exposure to being raped was associated with worse SIS-ADL, mRS, and tMOCA scores 12-mo post-stroke. Several other LSE were also independently associated with worse 12-mo SIS-ADL scores: witnessing a family member be injured or killed, divorce, and emotional abuse. Having a loved one be seriously ill was associated with better 12-mo t-MOCA scores. These findings were robust when early post-stroke acute stress levels were also included in the model. Women were significantly more likely to report being raped, experiencing emotional abuse, and having a seriously ill loved one. Demographics were not significantly associated with divorce or witnessing a family member injured or killed. Conclusions: Assessing specific types of exposure to LSE early in the post-stroke period may help identify at-risk patients who might benefit from additional post-stroke support to enhance their long-term functional and cognitive abilities.

Glutaredoxin regulation of primary root growth is associated with early drought stress tolerance in pearl millet.

Seedling root traits impact plant establishment under challenging environments. Pearl millet is one of the most heat and drought tolerant cereal crops that provides a vital food source across the sub-Saharan Sahel region. Pearl millet's early root system features a single fast-growing primary root which we hypothesize is an adaptation to the Sahelian climate. Using crop modeling, we demonstrate that early drought stress is an important constraint in agrosystems in the Sahel where pearl millet was domesticated. Furthermore, we show that increased pearl millet primary root growth is correlated with increased early water stress tolerance in field conditions. Genetics including genome-wide association study and quantitative trait loci (QTL) approaches identify genomic regions controlling this key root trait. Combining gene expression data, re-sequencing and re-annotation of one of these genomic regions identified a glutaredoxin-encoding gene PgGRXC9 as the candidate stress resilience root growth regulator. Functional characterization of its closest Arabidopsis homolog AtROXY19 revealed a novel role for this glutaredoxin (GRX) gene clade in regulating cell elongation. In summary, our study suggests a conserved function for GRX genes in conferring root cell elongation and enhancing resilience of pearl millet to its Sahelian environment.

Glutaredoxin regulation of primary root growth is associated with early drought stress tolerance in pearl millet

Seedling root traits impact plant establishment under challenging environments. Pearl millet is one of the most heat and drought tolerant cereal crops that provides a vital food source across the sub-Saharan Sahel region. Pearl millet’s early root system features a single fast-growing primary root which we hypothesize is an adaptation to the Sahelian climate. Using crop modeling, we demonstrate that early drought stress is an important constraint in agrosystems in the Sahel where pearl millet was domesticated. Furthermore, we show that increased pearl millet primary root growth is correlated with increased early water stress tolerance in field conditions. Genetics including genome-wide association study and quantitative trait loci (QTL) approaches identify genomic regions controlling this key root trait. Combining gene expression data, re-sequencing and re-annotation of one of these genomic regions identified a glutaredoxin-encoding gene PgGRXC9 as the candidate stress resilience root growth regulator. Functional characterization of its closest Arabidopsis homolog AtROXY19 revealed a novel role for this glutaredoxin (GRX) gene clade in regulating cell elongation. In summary, our study suggests a conserved function for GRX genes in conferring root cell elongation and enhancing resilience of pearl millet to its Sahelian environment.

On the modelling of distorted thin-walled stiffened panels via a scale reduction approach for a simplified structural stress analysis

To reduce the weight of cruise ships, the shipbuilding industry is interested in thin-walled superstructures, where the thickness of butt-welded plates in stiffened panels is under 5 mm. Compared to thick plates, thin ones can develop severe welding-induced distortions, which limit the validity of recommended early-design structural stress assessment methods. Therefore, computationally costly 3D non-linear numerical analysis must be used. For a quick and effective early design, this paper investigates on simplified computational models for thin-walled panels under uni-axial tension, considering the distortions measured on 4-mm thick, full-scale ship-deck panels. A 2D simply-supported analytical plate is shown to be sufficiently accurate (i.e., error <10%) at 150MPa for a distortion with maximum slope within 0.02rad and amplitude smaller than the thickness (t). Moreover, a 1D beam numerical analysis efficiently predicts local stresses around the butt weld when the maximum distortion amplitude is below 0.6×tmm. The distortion needs to be considered at least up to a length of half of the plate width from the weld location and can represent longitudinal profiles within 60% of the plate width. In conclusion, the early structural stress assessment of thin-walled panels can be significantly simplified, thus helping bridge the gap between complex numerical analysis and simplified analytical solutions.

Antioxidative Sirt1 and the Keap1-Nrf2 Signaling Pathway Impair Inflammation and Positively Regulate Autophagy in Murine Mammary Epithelial Cells or Mammary Glands Infected with Streptococcus uberis.

Streptococcus uberis mastitis in cattle infects mammary epithelial cells. Although oxidative responses often remove intracellular microbes, S. uberis survives, but the mechanisms are not well understood. Herein, we aimed to elucidate antioxidative mechanisms during pathogenesis of S. uberis after isolation from clinical bovine mastitis milk samples. S. uberis's in vitro pathomorphology, oxidative stress biological activities, transcription of antioxidative factors, inflammatory response cytokines, autophagosome and autophagy functions were evaluated, and in vivo S. uberis was injected into the fourth mammary gland nipple of each mouse to assess the infectiousness of S. uberis potential molecular mechanisms. The results showed that infection with S. uberis induced early oxidative stress and increased reactive oxygen species (ROS). However, over time, ROS concentrations decreased due to increased antioxidative activity, including total superoxide dismutase (T-SOD) and malondialdehyde (MDA) enzymes, plus transcription of antioxidative factors (Sirt1, Keap1, Nrf2, HO-1). Treatment with a ROS scavenger (N-acetyl cysteine, NAC) before infection with S. uberis reduced antioxidative responses and the inflammatory response, including the cytokines IL-6 and TNF-α, and the formation of the Atg5-LC3II/LC3I autophagosome. Synthesis of antioxidants determined autophagy functions, with Sirt1/Nrf2 activating autophagy in the presence of S. uberis. This study demonstrated the evasive mechanisms of S. uberis in mastitis, including suppressing inflammatory and ROS defenses by stimulating antioxidative pathways.