Stress Memory Research Articles

Quantifying the discrepancies in measuring applied stresses using Tangent Modulus Method (TMM)

The stress memory in rock under uniaxial cyclic compression is attributed to the nonlinear strains in rock due to crack initiation and propagation. When a rock is subjected to uniaxial compression, potential cracks with strengths lower than the applied stress initiates and propagates. When the specimen is unloaded and reloaded again, new cracks hardly occur until previously applied maximum stress is reached, beyond which new cracks are generated resulting in elastic strains. The tangent modulus method (TMM) is an approach commonly used to reconstruct the applied stress. This method involves plotting the incremental tangent modulus for two successive cycles against the stress, with the separation between the curves assumed to be the maximum stress previously applied. However, this method is sensitive to time and show its effectiveness under a certain range of time delay only. In this paper, we propose a modification to the TMM that eliminates the time dependency of the method. Uniaxial cyclic loading and unloading (UCLU) tests were performed on cylindrical rock specimens, and the effect of time delay on stress memory was observed. The results obtained from the modified technique indicate that the stress memory in rocks remains unaffected by time delay, contrary to the findings of the conventional TMM analysis.

Priming and cross-adaptation of plants to abiotic stresses: state of the problem and prospects

The review is devoted to the current state and prospects of research on the problem of plants priming and cross-adaptation to abiotic stress factors — mainly drought and high temperature. These studies are becoming increasingly relevant due to global climate change, as they reveal new approaches to increasing the crops resistance to stressors. The key link in this case is the formation of the so-called stress memory (priming) under the influence of moderate stress, which allows the plant to activate protective mechanisms faster and more effectively under the effect of the next harder stress of the same or a different nature (cross-adaptation) and thereby mitigate its impact compared to non-primed plants. In this regard, information on signaling systems that participate in the perception of a stress factor by a plant and trigger protective mechanisms through multi-cascade networks is considered. The results of experiments on priming plants with high temperature or drought at the beginning of the growing season to the action of these stressors at later development stages, as well as examples of cross-adaptation, when priming with drought increased thermotolerance and vice versa, are given. Possible mechanisms of stress memory formation and retention within one generation and its transference to subsequent generations (transgenerational stress memory) are briefly considered. At the same time, one of the unsolved problems remains the correctness of extrapolation results obtained in laboratory or controlled conditions to the practice of growing plants in the field. Certain side effects of priming should also be considered, as priming may cause some negative effects on plant physiology and productivity. Therefore, it is necessary to test whether the primed plants will perform as well as the control if the stress will not happen.

Ajustes fotossintéticos e concentração de prolina provavelmente estão ligados à memória de estresse em soja exposta a seca recorrente

ABSTRACT Drought stress is the main abiotic factor limiting soybean yield. The memory of recurrent water stress can provide greater efficiency in minimizing the negative effects of drought. Thus, the aim of this work was to understand the temporal adjustments in photosynthesis presented by soybeans when exposed to recurrent drought at the beginning of the flowering and grain filling stages. The experiment was carried out in a randomized block design with five replications, consisting of four treatments: i) WS-R1 (moderate water deficit at the beginning of flowering), ii) WS-R5 (severe water deficit during grain filling), iii) WS-R1+R5 (moderate water deficit at early flowering and severe water deficit during grain filling), and iv) WW (well-watered condition). Severe stress caused reductions in gas exchange parameters and the relative water content, with increased initial fluorescence and water use efficiency. The plants from the WS-R5 and WS-R1+R5 treatments showed a reduction in the apparent rate of electron transport in photosystem II (PSII), photochemical quenching, and effective quantum yield of PSII, as well as increased nonphotochemical quenching values. Furthermore, the proline concentration in the leaves was higher in plants from the WS-R1+R5 treatment, contributing to the greater ability to maintain turgid cells compared to the WS-R5 plants. The photosynthetic adjustments related to faster isohydric responses and photoprotective mechanisms in soybean plants subjected to recurrent drought allowed the maintenance in the weight or number of grains compared to plants without water restriction, demonstrating the activation of efficient memory mechanisms of response to water stress.

Mitigating abiotic stresses: A study on Pannonian basin wheat cultivars facing drought, cold and heat

Environmental stresses such as drought, cold and heat in Pannonia Basin significantly endanger the cell activity, plant growth and yields in wheat, which is one of the most strategic cereal grain crops in the world. As science and technology advance, new tools are developed while old ones are refined for use by breeders. Higher agronomical efficiency is possible by combining new and old tools to bridge the abiotic stress issues. Five cultivars of winter wheat (Simonida, Petrija, Ljubica, Zvezdana and NS Mila), were used in the study carried out at our experimental field (Novi Sad as a center of Pannonia Basin) across three consecutive growing seasons to assess genetic interaction and the level of tolerance and adaptability of different cultivars to abiotic stresses like drought conditions, cold and heat. Four quantitative yield components and grain yield were analiyed to assess expression of adapted genotypes in the region. Among the cultivars, Simonida, which has been in use for the longest period, exhibited the most consistent yield response. Additionally, it demonstrated some degree of partial tolerance to abiotic stress conditions, possibly due to the integration of stress memory into its genetic code, supported by statistical analysis findings.

Reliability of prospective and retrospective maternal reports of prenatal experiences

BackgroundExtant perinatal research utilizes retrospective reports on the prenatal environment, but there are limited data on the validity of retrospective data compared with prospective data. The current study examined the reliability of birth mothers’ memory of prenatal stress and distress and perinatal risks at 6-months postpartum with maternal reports gathered across each trimester of pregnancy and explored whether recall varied with maternal socioeconomic status.MethodsSurveys were collected from 34 pregnant women (M age = 29.14, SD = 5.06 years, 83% non-Hispanic White) on stress, distress, and pregnancy complications at 12(T1), 26(T2), and 38(T3) weeks of pregnancy, and at 6-month post-partum asking the same questions but specifically about the pregnancy. Cohen’s kappa and Pearson’s correlations were used to investigate maternal recall at post-partum with prospective reports at T1, T2, T3 and an average score of T1, T2, and T3. Correlations were also examined separately for those with high and relatively lower socioeconomic status.ResultsBirth mothers’ recall was generally reliable. Retrospective reports were most strongly related to prospective reports in T1 for perceived stress, T1 and T3 for anxiety symptoms and exposure to toxins, but T3 for depressive symptoms. Recall of pregnancy complications best reflected the average score across trimesters (rather than specific trimesters). Women with higher socioeconomic status better recalled prenatal (di)stress, but women with relatively lower socioeconomic status better recalled exposure to toxins.ConclusionThis study provides support for utilizing retrospective reports of maternal prenatal experiences at 6-months post-partum, with implications for interpretation of specific recalled phenotypes.

Evaluation of the effects of phenylephrine and prazosin injection into basolateral amygdala on the post-stress experience of memory retrieval in rats

The present study explored the effect of α1-adrenergic receptors in the basolateral amygdala (BLA) on memory formation in the hippocampus under repeated stress. Male rats received injections of the α1-adrenergic receptor agonist (phenylephrine) or antagonist (prazosin) bilaterally into the BLA five min before foot-shock stress, and emotional and spatial memory and in-vivo long-term potentiation (LTP) in the Cornu Ammonis (CA1) region of the hippocampus were examined. Foot-shock stress impaired performance in emotional and spatial memory tests. However, it had no significant effect on any of the LTP parameters in the hippocampus. Intra-BLA phenylephrine injection significantly impaired emotional and spatial memory performance in stressed animals. On the other hand, administration of intra-BLA prazosin significantly reduced emotional and spatial memory in the control (intact) animals. Neither of the two drugs had any significant effects on LTP parameters. Prazosin effectively impaired memory in the control, but not in the stressed rats. Stress appears to have suppressed the effect of prazosin, and it seems to be a significantly stronger stimulus than prazosin. Taken together, these findings provide new insights into the effects of α1-adrenergic receptors in the BLA on memory storage, during the stress experience.

The Hippocampal Response to Acute Corticosterone Elevation Is Altered in a Mouse Model for Angelman Syndrome.

Angelman Syndrome (AS) is a severe neurodevelopmental disorder, caused by the neuronal absence of the ubiquitin protein ligase E3A (UBE3A). UBE3A promotes ubiquitin-mediated protein degradation and functions as a transcriptional coregulator of nuclear hormone receptors, including the glucocorticoid receptor (GR). Previous studies showed anxiety-like behavior and hippocampal-dependent memory disturbances in AS mouse models. Hippocampal GR is an important regulator of the stress response and memory formation, and we therefore investigated whether the absence of UBE3A in AS mice disrupted GR signaling in the hippocampus. We first established a strong cortisol-dependent interaction between the GR ligand binding domain and a UBE3A nuclear receptor box in a high-throughput interaction screen. In vivo, we found that UBE3A-deficient AS mice displayed significantly more variation in circulating corticosterone levels throughout the day compared to wildtypes (WT), with low to undetectable levels of corticosterone at the trough of the circadian cycle. Additionally, we observed an enhanced transcriptomic response in the AS hippocampus following acute corticosterone treatment. Surprisingly, chronic corticosterone treatment showed less contrast between AS and WT mice in the hippocampus and liver transcriptomic responses. This suggests that UBE3A limits the acute stimulation of GR signaling, likely as a member of the GR transcriptional complex. Altogether, these data indicate that AS mice are more sensitive to acute glucocorticoid exposure in the brain compared to WT mice. This suggests that stress responsiveness is altered in AS which could lead to anxiety symptoms.

To Be or Not to Be? Are Reactive Oxygen Species, Antioxidants, and Stress Signalling Universal Determinants of Life or Death?

In the environmental and organism context, oxidative stress is complex and unavoidable. Organisms simultaneously cope with a various combination of stress factors in natural conditions. For example, excess light stress is accompanied by UV stress, heat shock stress, and/or water stress. Reactive oxygen species (ROS) and antioxidant molecules, coordinated by electrical signalling (ES), are an integral part of the stress signalling network in cells and organisms. They together regulate gene expression to redirect energy to growth, acclimation, or defence, and thereby, determine cellular stress memory and stress crosstalk. In plants, both abiotic and biotic stress increase energy quenching, photorespiration, stomatal closure, and leaf temperature, while toning down photosynthesis and transpiration. Locally applied stress induces ES, ROS, retrograde signalling, cell death, and cellular light memory, then acclimation and defence responses in the local organs, whole plant, or even plant community (systemic acquired acclimation, systemic acquired resistance, network acquired acclimation). A simplified analogy can be found in animals where diseases vs. fitness and prolonged lifespan vs. faster aging, are dependent on mitochondrial ROS production and ES, and body temperature is regulated by sweating, temperature-dependent respiration, and gene regulation. In this review, we discuss the universal features of stress factors, ES, the cellular production of ROS molecules, ROS scavengers, hormones, and other regulators that coordinate life and death.

AgNPs-Triggered Seed Metabolic and Transcriptional Reprogramming Enhanced Rice Salt Tolerance and Blast Resistance

Seeds are facing harsher environments due to the changing climate. Improving seeds' stress resilience is critical to reduce yield loss. Here, we propose that using ROS-generating nanoparticles (NPs) to prestimulate seeds would enhance the stress resilience of seeds and seedlings through triggering stress/immune responses. We examined this hypothesis by exposing AgNPs-primed rice (Oryza sativa L.) seeds under salt conditions (NaCl). The results showed that primed seeds exhibit accelerated germination speed, increased seedling vigor (from 22.5 to 47.6), biomass (11%), and root length (83%) compared to seeds with hydropriming treatment. Multiomics (metabolomics and transcriptomics) analyses reveal that AgNPs-priming triggered metabolic and transcriptional reprogramming in rice seeds. Signaling metabolites, such as salicylic acid, niacinamide, and glycerol-3-phosphate, dramatically increased upon AgNPs-priming. KEGG pathway analysis reveals that AgNPs-priming activated stress signaling and defense related pathways, such as plant hormone signal transduction, glutathione metabolism, flavone and flavonol biosynthesis, MAPK signaling pathway, and plant-pathogen interaction. These metabolic and transcriptional changes indicate that AgNPs-priming triggered stress/immune responses. More importantly, this "stress memory" can last weeks, providing protection to rice seedlings against salt stress and rice blast fungus (Magnaporthe oryzae). Overall, we show that prestimulated seeds with ROS-generating AgNPs not only enable faster and better germination under stress conditions, but also increase seedling resistance to biotic and abiotic stresses. This simple nanobiostimulant-based strategy may contribute to sustainable agriculture by maintaining agricultural production and reducing the use of pesticides.

Cross-stress memory: Salt priming at vegetative growth stages improves tolerance to drought stress during grain-filling in rice plants

The pre-exposure of plants to a potentially stressful condition can stimulate tolerance to subsequent stresses, a phenomenon associated with memory in plants. When the stimuli have different natures, a cross-tolerance phenomenon can take place. The objective of this study was to investigate whether the pre-exposure of rice plants to a saline stimulus at the vegetative stage has the potential to mitigate the effects of a drought event during grain-filling. By evaluating the transcriptional and physiological (e.g. hormones, gas exchange, growth parameters) responses, this study seek to identify likely long-term memory mechanisms. Therefore, rice plants were exposed to a pre-treatment in the vegetative stage induced by 150 mM NaCl solution for four days and then subjected to 16 days of water deficit in the reproductive stage. Physiological parameters were evaluated and the endogenous levels of the plant hormones abscisic acid (ABA), salicylic acid (SA) and jasmonic acid (JA) and RNA-sequencing (RNA-Seq) was measured to investigate transcriptional profiles of rice plants subjected to cross-stress. The results demonstrated that primed plants challenged by water stress during the grain-filling stage showed less electrolyte leakage, less damage to the photosynthetic apparatus and increased root growth. The higher ABA concentration in leaves was closely related to the above physiological responses. Along with JA and SA, ABA can be a determinant of long-term stress memory in rice. The annotation of specific cross-tolerance genes pointed to signaling and synthesis of hormones, photosynthesis, stomatal conductance, antioxidant system, glyoxylate cycle and transcription factors. It is concluded that priming with salt in the vegetative stage can mitigates the effects of drought during the reproductive stage at the transcriptional, physiological and hormonal levels.

Epigenetic stress memory: A new approach to study cold and heat stress responses in plants.

Understanding plant stress memory under extreme temperatures such as cold and heat could contribute to plant development. Plants employ different types of stress memories, such as somatic, intergenerational and transgenerational, regulated by epigenetic changes such as DNA and histone modifications and microRNAs (miRNA), playing a key role in gene regulation from early development to maturity. In most cases, cold and heat stresses result in short-term epigenetic modifications that can return to baseline modification levels after stress cessation. Nevertheless, some of the modifications may be stable and passed on as stress memory, potentially allowing them to be inherited across generations, whereas some of the modifications are reactivated during sexual reproduction or embryogenesis. Several stress-related genes are involved in stress memory inheritance by turning on and off transcription profiles and epigenetic changes. Vernalization is the best example of somatic stress memory. Changes in the chromatin structure of the Flowering Locus C (FLC) gene, a MADS-box transcription factor (TF), maintain cold stress memory during mitosis. FLC expression suppresses flowering at high levels during winter; and during vernalization, B3 TFs, cold memory cis-acting element and polycomb repressive complex 1 and 2 (PRC1 and 2) silence FLC activation. In contrast, the repression of SQUAMOSA promoter-binding protein-like (SPL) TF and the activation of Heat Shock TF (HSFA2) are required for heat stress memory. However, it is still unclear how stress memory is inherited by offspring, and the integrated view of the regulatory mechanisms of stress memory and mitotic and meiotic heritable changes in plants is still scarce. Thus, in this review, we focus on the epigenetic regulation of stress memory and discuss the application of new technologies in developing epigenetic modifications to improve stress memory.

Self-defining memories and past academic stress in Chinese and American college students: a replication and extension of Wang and Singer (2021)

ABSTRACT The current study replicated Wang and Singer’s ([2021]. A cross-cultural study of self-defining memories in Chinese and American college students. Frontiers in Psychology, 11. https://doi.org/10.3389/fpsyg.2020.622527) finding that Chinese college students from the People’s Republic of China (PRC) recalled more self-defining memories (SDMs) focused on high school academic stress than their American counterparts. Seventy-eight American students from a private 4-year liberal arts college and 96 Chinese students from 13 different Chinese universities recalled two SDMs and rated them for affect, recall frequency, and importance. Once again, Chinese college students were more likely than American students to recall academic stress SDMs, but also expressed more redemptive themes in these memories. Overall, Chinese students rated their SDMs as more positive than the Americans, while the American sample tended to recall their negative memories more frequently. Contrasting the SDMs, American students self-reported higher levels of stress about their high school workload and less academic self-confidence. Regressions linked more negative affect in American SDMs to these work load and self-confidence concerns. Chinese students’ SDM negative affect was most strongly predicted by perceived academic stress linked to parental and teachers’ expectations. The discussion highlights the potential influence of Confucian values in the Chinese students’ responses to past academic stress and their internalisation of academic stress memories in their narrative identity.

Thermal priming and bleaching hormesis in the staghorn coral, Acropora cervicornis (Lamarck 1816)

Stress memory is a highly conserved phenomenon that enables the survival of organisms. There is evidence of stress memory in stony corals, but its costs and benefits remain largely unknown. To characterize coral stress memory, eight genets of Acropora cervicornis corals were primed with varying doses of thermal stress in the laboratory, allowed to recover for eight days and then experimentally bleached. Symbiont density and chlorophyll decreased linearly with increasing priming intensity, demonstrating a dose-dependent upfront ‘cost’ of priming. The highest priming dose (8.8 °C·days) led to bleaching after priming and mortality at the end of the recovery period, however, in lower priming intensity treatments, differences in symbiont density and chlorophyll detected immediately after priming did not persist after recovery. Primed corals did not bleach significantly less than naïve corals, owing to high within treatment variance between genets. However, the relationship between priming intensity (°C·days) and thermal bleaching severity (i.e., symbiont density) was hormetic (p = 0.055). Priming with low doses of thermal stress (1.8 to 4.6 °C·days) resulted in 32–51% greater symbiont retention, but the highest dose (8.8 °C·days) led to severe bleaching like that observed in naïve corals. This study empirically demonstrates coral bleaching hormesis in the laboratory, providing support for environmentally mediated priming in Scleractinians. The presence of coral bleaching hormesis suggests there may be the potential to extend resilient bleaching phenotypes for some corals. However, not all host genotypes may benefit from hardening, an essential consideration in the applicability of stress hardening for coral restoration.

No stress memory pattern was detected in sugar maple and white spruce seedlings subjected to experimental droughts

AbstractAn increase in the frequency and magnitude of drought events threatens the health of forests and the economic, ecological, and societal services they provide. It has been widely demonstrated that trees undergoing a succession of stresses may accumulate lesions that in turn lead to a decrease in their vigor and eventually to death. However, recent studies have shown that a nonlethal stress should also initiate a stress memory, which triggers a faster and stronger plant defensive response when a new stress occurs. Although this mechanism is well understood in many herbaceous plants, a better understanding in trees is needed. The aim of our study was to explore the capacity of two forest tree species to develop a stress memory. A greenhouse experiment was conducted to evaluate the tree seedlings' vigor after one or two consecutive droughts separate from a rehydration period during the same growing season. No stress memory pattern was observed for the two tree species as, on the contrary, we even observed a stress accumulation pattern in sugar maple. It remains possible that some individuals in our study developed stress memory, but that we were not able to detect it. The fine‐tuning of experimental parameters and the conducting of longitudinal studies would be helpful to detect individual capacity in stress memory activation.

Effectiveness of 8 weeks of vestibular exercises on stress, sleep, and cognitive parameters in hypertensive patients

Background: It was hypothesized that vestibular stimulation causes beneficial effects in hypertensive patients as so as in diabetic individuals. Aims and Objectives: The present study was undertaken to observe the effectiveness of 8 weeks of vestibular exercises on stress, sleep, and cognitive parameters in hypertensive patients. Materials and Methods: A total of eighty male and female stage 1 hypertensive individuals were part of the study after obtaining voluntary, written informed consent. Vestibular exercises comprising three steps with a time period of 45 min per session were administered to the participants of the intervention group. Two sessions per week were administered as mentioned in the literature. Stress levels were assessed by the perceived stress scale. Sleep was assessed by the insomnia severity index. A spatial and verbal memory test was used to assess the spatial and verbal memory scores. Results: There was no significant difference in the demographical parameters of the control and intervention groups. There is no significant difference in stress, sleep scores, and spatial and verbal memory scores among the control and intervention groups. There was a significant decrease in the stress scores and insomnia scores, and a significant improvement in the spatial and verbal memory scores in the intervention group after the intervention when compared with the control group. Conclusion: The present study results suggest that vestibular exercises have a positive impact on reducing stress and improving sleep and cognition in hypertensive individuals. The study highlights the need for further detailed studies in this area to recommend the inclusion of vestibular exercises as adjunctive therapy in the management of hypertension.

Metabolic and Transcriptional Stress Memory in Sorbus pohuashanensis Suspension Cells Induced by Yeast Extract

Plant stress memory can provide the benefits of enhanced protection against additional stress exposure. Here, we aimed to explore the responses of recurrent and non-recurrent yeast extract (YE) stresses in Sorbus pohuashanensis suspension cells (SPSCs) at metabolomics and transcriptional levels. Biochemical analyses showed that the cell wall integrity and antioxidation capacity of SPSCs in the pretreated group were evidently improved. Metabolic analysis showed that there were 39 significantly altered metabolites in the pretreated group compared to the non-pretreated group. Based on the transcriptome analysis, 219 differentially expressed genes were obtained, which were highly enriched in plant-pathogen interaction, circadian rhythm-plant, oxidative phosphorylation, and phenylpropanoid biosynthesis. Furthermore, the correlation analysis of the transcriptome and metabolome data revealed that phenylpropanoid biosynthesis involved in the production of biphenyl phytoalexins may play a critical role in the memory response of SPSC to YE, and the key memory genes were also identified, including PAL1, BIS1, and BIS3. Collectively, the above results demonstrated that the memory responses of SPSC to YE were significant in almost all levels, which would be helpful for better understanding the adaptation mechanisms of medicinal plants in response to biotic stress, and laid a biotechnological foundation to accumulate favorable antimicrobial drug candidates from plant suspension cells.

DNA methylation in clonal duckweed (Lemna minor L.) lineages reflects current and historical environmental exposures.

Environmentally induced DNA methylation variants may mediate gene expression responses to environmental changes. If such induced variants are transgenerationally stable, there is potential for expression responses to persist over multiple generations. Our current knowledge in plants, however, is almost exclusively based on studies conducted in sexually reproducing species where the majority of DNA methylation changes are subject to resetting in germlines, limiting the potential for transgenerational epigenetics stress memory. Asexual reproduction circumvents germlines, and may therefore be more conducive to long-term inheritance of epigenetic marks. Taking advantage of the rapid clonal reproduction of the common duckweed Lemna minor, we hypothesize that long-term, transgenerational stress memory from exposure to high temperature can be detected in DNA methylation profiles. Using a reduced representation bisulphite sequencing approach (epiGBS), we show that temperature stress induces DNA hypermethylation at many CG and CHG cytosine contexts but not CHH. Additionally, differential methylation in CHG context that was observed was still detected in a subset of cytosines, even after 3-12 generations of culturing in a common environment. This demonstrates a memory effect of stress reflected in the methylome and that persists over multiple clonal generations. Structural annotation revealed that this memory effect in CHG methylation was enriched in transposable elements. The observed epigenetic stress memory is probably caused by stable transgenerational persistence of temperature-induced DNA methylation variants across clonal generations. To the extent that such epigenetic memory has functional consequences for gene expression and phenotypes, this result suggests potential for long-term modulation of stress responses in asexual plants.

Stress memory in two generations of Plantago major from radioactive and chemical contaminated areas after the cessation of exposure

Hypothesis The differences in viability, root length, and pro/antioxidant features of Plantago major seedlings identified in seed progeny formed in areas of radioactive and chemical contamination can persist in subsequent generations after the elimination of the stress. Materials and methods The seed mixtures of F1 generation were collected from P. major natural populations (P plants) growing for a long time in the East Ural Radioactive Trace, the Karabash Copper Smelter zone, and background area. The seeds of F2 generation were obtained from F1 generation plants grown on experimental plots with ‘clean’ agricultural background; F3 generation was grown from F2 generation on the same plots. The viability of seed progeny was estimated by survival rate and root length. Pro/antioxidant features were determined spectrophotometrically by malondialdehyde content, superoxide dismutase and catalase activities, and total content of low molecular weight antioxidants in seedlings. Results and conclusions The hypothesis about the persistence of effects from chronic exposure to ionizing radiation and chemical contamination in the generations’ sequence of P. major after the removal of stress was confirmed only partially. The data obtained indicated that changes in the prooxidant and antioxidant features of plants in response to low doses of ionizing radiation can persist for at least in two generations after the stress removal. In the case of long-term exposure to chemical contaminants, we observed the persistence of the effect in a succession of generations only on the morphological indicator of root length.

P128 Effect of acute exercise on stress and working memory following sleep restriction

Abstract Introduction Cognitive impairment poses a serious risk to worker safety. We investigated the interacting effects of acute exercise and sleep restriction (SR) on stress and working memory (WM). Methods Our randomized crossover design had 14 adults (10 M, 23 ± 3 years) complete two sessions under different sleep conditions (normal sleep (NS)=8h; restricted sleep (RS)=4h). Sleep duration was verified by validated wrist-worn actigraphy (Fitbit tracker). Salivary cortisol levels (stress indicator) and WM (via n-back task performance) were measured before and after high-intensity exercise on a cycle ergometer. Data was collected at the same time of day for each participant and a washout interval of at least 72-hours separated experimental conditions. Results A two-factor repeated measure ANOVA revealed sleep condition to have a significant effect on cortisol levels (F(1,13)=7.78, p<0.05) and n-back reaction time (RT) (F(1,13) = 10.54, p<0.01), but not response accuracy. Post-hoc dependent t-tests showed that RS lead to slower RTs compared to the NS condition (t(27)=3.32, p<0.01), as well as higher cortisol levels both before (t(13)=2.22, p<0.05) and after (t(13)=2.64, p<0.05) exercise. Acute exercise did not affect cortisol levels, but did appear to have a facilitative effect on response accuracy (t(27)=2.13, p<0.05), as well as RT in both sleep conditions ( ES t(13)=2.32, p<0.05. RS t(13)=2.2, p<0.05). Discussion These findings suggest that RS may lead to increased stress and impaired cognitive function, while acute exercise may serve as an effective tool for counteracting the negative cognitive effects induced by SR.

Transgenerational stress memory in plants is mediated by upregulation of the antioxidative system

Transgenerational stress memory transferred from parents to offspring may enable plants to respond to changing environments rapidly. Yet transgenerational adaptive effects and underlying mechanisms in response to waterlogging and drought are still unclear. Furthermore, transgenerational cross-stress tolerance, pre-adapting offspring to any stress when maternal plants experienced stress, is currently understudied. We conducted a full-factorial pot experiment over two generations, using four perennial plant species and subjecting maternal and offspring plants to waterlogging and drought. We hypothesized that offspring experiencing stress performed better when mothers had experienced stress before, irrespective of the type of stress. We found increased biomass and reproductive output in offspring experiencing the same stress conditions as their mothers (transgenerational adaptive effects). However, a maternal stress experience per se did not pre-condition offspring to other types of stress. Transgenerational adaptive effects were linked to changes in the antioxidative system of one species, reducing oxidative damage through upregulation of protective enzymes in offspring experiencing the same conditions as their mothers. Our research provides evidence for transgenerational waterlogging and drought memory and links this to underlying photosynthetic and redox-related mechanisms. Transgenerational adaptive effects acting on the antioxidative system might therefore contribute to the rapid responses of plants to environmental change.