Nitrogen deposition differentially regulates the sensitivity of gross primary productivity to extreme drought versus wetness.

Global hydroclimatic variability is increasing with more frequent extreme dry and wet years, severely destabilizing terrestrial ecosystem productivity. However, what regulates the consequence of precipitation extremes on productivity remains unclear. Based on a 9-year field manipulation experiment on the Qinghai-Tibetan Plateau, we found that the responses of gross primary productivity (GPP) to extreme drought and wetness were differentially regulated by nitrogen (N) deposition. Over increasing N deposition, extreme dry events reduced GPP more. Among the 12 biotic and abiotic factors examined, this was mostly explained by the increased plant canopy height and proportion of drought-sensitive species under N deposition, making photosynthesis more sensitive to hydraulic stress. While extreme wet events increased GPP, their effect did not shift over N deposition. These site observations were complemented by a global synthesis derived from the GOSIF GPP dataset, which showed that GPP sensitivity to extreme drought was larger in ecosystems with higher N deposition, but GPP sensitivity to extreme wetness did not change with N deposition. Our findings indicate that intensified hydroclimatic variability would lead to a greater loss of land carbon sinks in the context of increasing N deposition, due to that GPP losses during extreme dry years are more pronounced, yet without a synchronous increase in GPP gains during extreme wet years. The study implies that the conservation and management against climate extremes merit particular attention in ecosystems subject to N deposition.

Narrow Directed Black Phosphorus Nanoribbons Produced by A Reformative Mechanical Exfoliation Approach.

Black phosphorus nanoribbons (PNRs) are ideal candidates for constructing electronic and optoelectronic devices owing to their unique structure and high bandgap tunability. However, the preparation of high-quality narrow PNRs aligned along the same direction is very challenging. Here, a reformative mechanical exfoliation approach combining tape and polydimethylsiloxane (PDMS) exfoliations to fabricate high-quality, narrow, and directed PNRs with smooth edges for the first time is developed. In this method, partially-exfoliated PNRs are first formed on thick black phosphorus (BP) flakes via the tape exfoliation and further peeled off to obtain separated PNRs via the PDMS exfoliation. The prepared PNRs have widths from a dozen to hundreds of nanometers (down to 15 nm) and a mean length of 18 µm. It is found that the PNRs can align along a same direction and the length directions of directed PNRs are along the zigzag direction. The formation of PNRs is attributed to that the BP prefers to be unzipped along the zigzag direction and has an appropriate magnitude of interaction force with the PDMS substrate. The fabricated PNR/MoS2 heterojunction diode and PNR field-effect transistor exhibit good device performance. This work provides a new pathway to achieve high-quality, narrow, and directed PNRs for electronic and optoelectronic applications.

GeoDILI: A Robust and Interpretable Model for Drug-Induced Liver Injury Prediction Using Graph Neural Network-Based Molecular Geometric Representation.

Drug-induced liver injury (DILI) is a significant cause of drug failure and withdrawal due to liver damage. Accurate prediction of hepatotoxic compounds is crucial for safe drug development. Several DILI prediction models have been published, but they are built on different data sets, making it difficult to compare model performance. Moreover, most existing models are based on molecular fingerprints or descriptors, neglecting molecular geometric properties and lacking interpretability. To address these limitations, we developed GeoDILI, an interpretable graph neural network that uses a molecular geometric representation. First, we utilized a geometry-based pretrained molecular representation and optimized it on the DILI data set to improve predictive performance. Second, we leveraged gradient information to obtain high-precision atomic-level weights and deduce the dominant substructure. We benchmarked GeoDILI against recently published DILI prediction models, as well as popular GNN models and fingerprint-based machine learning models using the same data set, showing superior predictive performance of our proposed model. We applied the interpretable method in the DILI data set and derived seven precise and mechanistically elucidated structural alerts. Overall, GeoDILI provides a promising approach for accurate and interpretable DILI prediction with potential applications in drug discovery and safety assessment. The data and source code are available at GitHub repository (https://github.com/CSU-QJY/GeoDILI).

An Uncertainty-Guided Deep Learning Method Facilitates Rapid Screening of CYP3A4 Inhibitors.

Cytochrome P450 3A4 (CYP3A4), a prominent member of the P450 enzyme superfamily, plays a crucial role in metabolizing various xenobiotics, including over 50% of clinically significant drugs. Evaluating CYP3A4 inhibition before drug approval is essential to avoiding potentially harmful pharmacokinetic drug-drug interactions (DDIs) and adverse drug reactions (ADRs). Despite the development of several CYP inhibitor prediction models, the primary approach for screening CYP inhibitors still relies on experimental methods. This might stem from the limitations of existing models, which only provide deterministic classification outcomes instead of precise inhibition intensity (e.g., IC50) and often suffer from inadequate prediction reliability. To address this challenge, we propose an uncertainty-guided regression model to accurately predict the IC50 values of anti-CYP3A4 activities. First, a comprehensive data set of CYP3A4 inhibitors was compiled, consisting of 27,045 compounds with classification labels, including 4395 compounds with explicit IC50 values. Second, by integrating the predictions of the classification model trained on a larger data set and introducing an evidential uncertainty method to rank prediction confidence, we obtained a high-precision and reliable regression model. Finally, we use the evidential uncertainty values as a trustworthy indicator to perform a virtual screening of an in-house compound set. The in vitro experiment results revealed that this new indicator significantly improved the hit ratio and reduced false positives among the top-ranked compounds. Specifically, among the top 20 compounds ranked with uncertainty, 15 compounds were identified as novel CYP3A4 inhibitors, and three of them exhibited activities less than 1 µM. In summary, our findings highlight the effectiveness of incorporating uncertainty in compound screening, providing a promising strategy for drug discovery and development.

Effect of different dry matter content on fermentation characteristics and nutritional quality of Napier grass silage with novel lactic acid bacteria strains.

To investigate the characteristics of different LAB strains isolated from subtropics and their effects on Napier grass (Pennisetum purpureum Schum.) silage with two dry matter (DM) levels, sugar fermentation pattern, and growth profiles of three screened lactic acid bacteria (LAB) strains [Pediococcus pentosaceus (PP04), Weissella cibaria (WC10), and Lactobacillus plantarum (LP694)] were characterized, and then used either individually or in combination at 1.0 × 106 cfu g-1 fresh weight to inoculate grass having 15% or 25% DM. Treatments were applied: (1) no inoculant (control); (2) PP04; (3) WC10; (4) LP694; (5) M-1 (PP04: WC10 = 2:1); (6) M-2 (PP04: LP694 = 1:2); (7) M-3 (WC10: LP694 = 2:1); (8) M-4 (PP04: WC10: LP694 = 2:1:1). The results showed that all inoculations increased LAB, DM recovery, and lactic acid (LA) concentration, while decreasing pH, the ammonia nitrogen/total nitrogen (NH3-N/TN), and butyric acid (BA) concentration compared to control group in both DM. However, the effect of inoculations was very limited at 15% DM. Silages with inoculants achieved higher silage quality at 25% DM than 15% DM. The different LAB inoculants result in significant differences in silage quality, while W. cibaria decreased the pH and inhibited the growth of undesirable bacteria and those characteristics were not affected by the DM content.

Physiological attributes and transcriptomics analyses reveal the mechanism response of Helictotrichon virescens to low temperature stress.

BACKGROUND: Helictotrichon virescens is a perennial grass that is primarily distributed in high altitude areas of 2000 ~ 4500 m. It is widely cultivated in the Qinghai-Tibet Plateau of China, strongly resistant to cold, and an essential part of the wild herbs in this region. However, the molecular mechanism of the response of H. virescens to low temperature stress and the key regulatory genes for specific biological processes are poorly understood. RESULTS: Physiological and transcriptome analyses were used to study the cold stress response mechanism in H virescens. During the low temperature stress period, the content of chlorophyll a and b decreased more and more with the delay of the treatment time. Among them, the difference between the controls was not significant, and the difference between the control and the treatment was significant. At the same time, the expression of related differential genes was up-regulated during low temperature treatment. In addition, the plant circadian pathway is crucial for their response to cold stress. The expression of differentially expressed genes that encode LHY and HY5 were strongly up-regulated during cold stress. CONCLUSIONS: This study should help to fully understand how H. virescens responds to low temperatures. It answers pertinent questions in the response of perennial herbs to cold stress, i.e., how light and low temperature signals integrate to regulate plant circadian rhythms and Decrease of content of chlorophylls (which can be also accompanied with decrease of total quantity of reaction centers) leads to an increase in photosynthetic damage.

Litter manipulation enhances plant community heterogeneity via distinct mechanisms: The role of distribution patterns of plant functional composition and niche breadth variability.

Plant litter can greatly alter community compositional dynamics and variability of intraspecific interactions in grasslands, and thus the overall ecosystem structure and functions. However, whether plant activity can be driven by plant litter to modify plant community heterogeneity remains poorly explored. We investigate the responses of plant community heterogeneity to litter addition as well as their associated mechanisms. Here we conducted a three-year field experiment in a Tibetan alpine meadow to explore the effects of multiple plant litter addition (five mass levels and three species) on plant communities. We found that the effect of litter manipulation on plant community heterogeneity was mainly driven by litter mass rather than litter species. Higher litter mass manipulation significantly enhanced plant community heterogeneity, which was mainly determined by the niche breadth of forbs and the distribution patterns of functional composition rather than plant diversity. Our findings provide significant insights for understanding the effects of plant litter on grassland ecosystem dynamics to maintain the structure and function of ecosystems. Furthermore, this study suggests that reasonable management practices (e.g., moderate grazing in non-growing seasons) may be pivotal in achieving sustainability of grassland systems through plant litter dynamics.

Ultrastructural and Photosynthetic Responses of Pod Walls in Alfalfa to Drought Stress.

Increasing photosynthetic ability as a whole is essential for acquiring higher crop yields. Nonleaf green organs (NLGOs) make important contributions to photosynthate formation, especially under stress conditions. However, there is little information on the pod wall in legume forage related to seed development and yield. This experiment is designed for alfalfa (Medicago sativa) under drought stress to explore the photosynthetic responses of pod walls after 5, 10, 15, and 20 days of pollination (DAP5, DAP10, DAP15, and DAP20) based on ultrastructural, physiological and proteomic analyses. Stomata were evidently observed on the outer epidermis of the pod wall. Chloroplasts had intact structures arranged alongside the cell wall, which on DAP5 were already capable of producing photosynthate. The pod wall at the late stage (DAP20) still had photosynthetic ability under well-watered (WW) treatments, while under water-stress (WS), the structure of the chloroplast membrane was damaged and the grana lamella of thylakoids were blurry. The chlorophyll a and chlorophyll b concentrations both decreased with the development of pod walls, and drought stress impeded the synthesis of photosynthetic pigments. Although the activity of ribulose-1,5-bisphosphate carboxylase (RuBisCo) decreased in the pod wall under drought stress, the activity of phosphoenolpyruvate carboxylase (PEPC) increased higher than that of RuBisCo. The proteomic analysis showed that the absorption of light is limited due to the suppression of the synthesis of chlorophyll a/b binding proteins by drought stress. Moreover, proteins involved in photosystem I and photosystem II were downregulated under WW compared with WS. Although the expression of some proteins participating in the regeneration period of RuBisCo was suppressed in the pod wall subjected to drought stress, the synthesis of PEPC was induced. In addition, some proteins, which were involved in the reduction period of RuBisCo, carbohydrate metabolism, and energy metabolism, and related to resistance, including chitinase, heat shock protein 81-2 (Hsp81-2), and lipoxygenases (LOXs), were highly expressed for the protective response to drought stress. It could be suggested that the pod wall in alfalfa is capable of operating photosynthesis and reducing the photosynthetic loss from drought stress through the promotion of the C4 pathway, ATP synthesis, and resistance ability.

GABAergic Interneuron Differentiation in the Basal Forebrain Is Mediated through Direct Regulation of Glutamic Acid Decarboxylase Isoforms by Dlx Homeobox Transcription Factors.

GABA is the key inhibitory neurotransmitter in the cortex but regulation of its synthesis during forebrain development is poorly understood. In the telencephalon, members of the distal-less (Dlx) homeobox gene family are expressed in, and regulate the development of, the basal ganglia primodia from which many GABAergic neurons originate and migrate to other forebrain regions. The Dlx1/Dlx2 double knock-out mice die at birth with abnormal cortical development, including loss of tangential migration of GABAergic inhibitory interneurons to the neocortex (Anderson et al., 1997a). We have discovered that specific promoter regulatory elements of glutamic acid decarboxylase isoforms (Gad1 and Gad2), which regulate GABA synthesis from the excitatory neurotransmitter glutamate, are direct transcriptional targets of both DLX1 and DLX2 homeoproteins in vivo Further gain- and loss-of-function studies in vitro and in vivo demonstrated that both DLX1 and DLX2 are necessary and sufficient for Gad gene expression. DLX1 and/or DLX2 activated the transcription of both Gad genes, and defects in Dlx function disrupted the differentiation of GABAergic interneurons with global reduction in GABA levels in the forebrains of the Dlx1/Dlx2 double knock-out mouse in vivo Identification of Gad genes as direct Dlx transcriptional targets is significant; it extends our understanding of Dlx gene function in the developing forebrain beyond the regulation of tangential interneuron migration to the differentiation of GABAergic interneurons arising from the basal telencephalon, and may help to unravel the pathogenesis of several developmental brain disorders.SIGNIFICANCE STATEMENT GABA is the major inhibitory neurotransmitter in the brain. We show that Dlx1/Dlx2 homeobox genes regulate GABA synthesis during forebrain development through direct activation of glutamic acid decarboxylase enzyme isoforms that convert glutamate to GABA. This discovery helps explain how Dlx mutations result in abnormal forebrain development, due to defective differentiation, in addition to the loss of tangential migration of GABAergic inhibitory interneurons to the neocortex. Reduced numbers or function of cortical GABAergic neurons may lead to hyperactivity states such as seizures (Cobos et al., 2005) or contribute to the pathogenesis of some autism spectrum disorders. GABAergic dysfunction in the basal ganglia could disrupt the learning and development of complex motor and cognitive behaviors (Rubenstein and Merzenich, 2003).

Domestic honeybees affect the performance of pre-dispersal seed predators in an alpine meadow.

Flowering plants interact simultaneously with mutualistic pollinators and antagonistic herbivores such that plant-mediated interactions between pollinators and herbivores must exist. Although the effects of herbivores on pollinator behavior have been investigated extensively, the effect of pollinators on herbivore performance has seldom been explored. We hypothesized that insect pollinators could improve the survival and growth of pre-dispersal seed predators by increasing seed production. We tested this hypothesis along three transects radiating from well-established apiaries in an alpine meadow by supplementing pollination in sites close to and distant from apiaries and subsequently examining seed production of the dominant nectariferous plant species Saussurea nigrescens (Asteraceae) and the performance of three dominant pre-dispersal seed predators (tephritid fly species). Pollen supplementation (1) significantly increased seed set and mass of developed seed per capitulum (i.e., flowerhead) in the distant but not the close sites, (2) did not change the survival and growth rates of the smaller-bodied species (Tephritis femoralis and Campiglossa nigricauda) at either site, but (3) improved the performance of the larger-bodied seed predator (Terellia megalopyge) at distant sites but not close sites. In addition, the larger-bodied tephritid fly showed higher infestation rates and relative abundance in the close sites than in the distant sites, whereas the smaller-bodied species had lower relative abundances in the close sites and similar infestation rates in both site types. These observations demonstrate contrasting effects of plant mutualists on the performance of antagonists with potential consequences for population sizes of insect herbivores.

Ecological restoration and its effects on a regional climate: the source region of the Yellow River, China.

The source region of the Yellow River, China, experienced degradation during the 1980s and 1990s, but effective ecological restoration projects have restored the alpine grassland ecosystem. The local government has taken action to restore the grassland area since 1996. Remote sensing monitoring results show an initial restoration of this alpine grassland ecosystem with the structural transformation of land cover from 2000 to 2009 as low- and high-coverage grassland recovered. From 2000 to 2009, the low-coverage grassland area expanded by over 25% and the bare soil area decreased by approximately 15%. To examine the relationship between ecological structure and function, surface temperature (Ts) and evapotranspiration (ET) levels were estimated to study the dynamics of the hydro-heat pattern. The results show a turning point in approximately the year 2000 from a declining ET to a rising ET, eventually reaching the 1990 level of approximately 1.5 cm/day. We conclude that grassland coverage expansion has improved the regional hydrologic cycle as a consequence of ecological restoration. Thus, we suggest that long-term restoration and monitoring efforts would help maintain the climatic adjustment functions of this alpine grassland ecosystem.

Phylogeographic analysis reveals extensive genetic variation of native grass Elymus nutans (Poaceae) on the Qinghai-Tibetan plateau.

Introduction: Elymus nutans holds ecological and pastoral significance due to its adaptability and nutritional value, the Qinghai-Tibet Plateau (QTP) is a key hub for its genetic diversity. To conserve and harness its genetic resources in highland ecosystems, a thorough assessment is vital. However, a comprehensive phylogeographic exploration of E. nutans is lacking. The objective of this study was to unravel the genetic diversity, adaptation, and phylogenetics of E. nutans populations. Methods: Encompassing 361 individuals across 35 populations, the species' genetic landscape and dynamic responses to diverse environments were decoded by using four chloroplast DNA (cpDNA) sequences and nine microsatellite markers derived from the transcriptome. Results and discussion: This study unveiled a notable degree of genetic diversity in E. nutans populations at nuclear (I = 0.46, He = 0.32) and plastid DNA levels (Hd = 0.805, π = 0.67). Analysis via AMOVA highlighted genetic variation predominantly within populations. Despite limited isolation by distance (IBD), the Mekong-Salween Divide (MSD) emerged as a significant factor influencing genetic differentiation and conserving diversity. Furthermore, correlations were established between external environmental factors and effective alleles of three EST-SSRs (EN5, EN57 and EN80), potentially linked to glutathione S-transferases T1 or hypothetical proteins, affecting adaptation. This study deepens the understanding of the intricate relationship between genetic diversity, adaptation, and environmental factors within E. nutans populations on the QTP. The findings shed light on the species' evolutionary responses to diverse ecological conditions and contribute to a broader comprehension of plant adaptation mechanisms.

Forage taste agents manage plant communities through modifying grazing behavior of yak in alpine meadow.

The use of taste agents to regulate the grazing behavior of livestock is a new attempt in pasture management, but the effects on grassland plant communities are not clear at present. Therefore, the following scientific questions need to be addressed: (1) how do different taste agents affected plant community structure by changing feed intake? (2) What was the mechanism of this effect? We proposed the following hypotheses: (1) Salt and sweetener increased feed intake of livestock and decreased the biomass of plant community, while bitters did the opposite. (2) Taste agents can regulate the relationship between plant species, and different taste agents can enhance or weaken the competitiveness of the different plants. In order to test the hypothesis, a grazing experiment with yaks was conducted in the alpine meadows of the Tibetan Plateau. Denatonium benzoate (Bitterant), NaCl (Salt), and sodium cyclamate (Sweetener) were sprayed onto the meadows twice a year, along with a control treatment of tap water. The results showed that (1) Salt increased the feed intake of yak significantly; bitterant decreased the feed intake of livestock and increased the biomass of plant community. (2) Salt increased the Pielou index of the plant community significantly. (3) The stability of plant community ranking from high to low is as follows: Control > Bitterant > Sweetener > Salt. (4) Bitterant and salt improved grazing tolerance of grassland and salt reduced the edibility of grassland. (5) The use of taste agents reduced the correlation between dominant species and led to the fragmentation of the relationship chain. The results of this study will provide a theoretical basis for using taste agents to regulate the community, species biodiversity management, restoration of degraded grassland, promoting utilization of grassland though controlling livestock selectivity.

Microbiome and response surface methodology analyses reveal Acetobacter pasteurianus as the core bacteria responsible for aerobic spoilage of corn silage (Zea mays) in hot and humid areas.

Introduction: Weak aerobic stability is a notable challenge for whole-plant corn silage, particularly in hot and humid regions. Acetobacter is commonly regarded as an indicator of aerobic deterioration in silage, yet its precise role in fermentation and during aerobic exposure, as well as the factors that promote its growth, remain insufficiently understood. Methods: In this study, whole-plant corn silage was prepared using a bagged method with controlled dry matter (DM) content at 20%, 25%, and 30%, and initial concentrations of A. pasteurianus at 40%, 50%, and 60%. The silage was stored for 60 days under varying temperatures (20°C, 30°C, and 40°C). Following the anaerobic storage phase, the silage was exposed to air at room temperature (20-25°C) for 7 days, both with and without A. pasteurianus inoculation. Results: The results demonstrated that A. pasteurianus did not impact the nutritional value of the silage during anaerobic fermentation, maintaining a low pH (< 3.80). However, during aerobic exposure, the presence of A. pasteurianus significantly reduced the aerobic stability of the silage. The microbial community shifted from primarily Klebsiella species initially to Lactobacillus and Acetobacter species post-ensiling. During the aerobic exposure phase, A. pasteurianus and A. fabarum became the dominant species. Response Surface Methodology (RSM) analysis identified optimal conditions for the proliferation of A. pasteurianus during the aerobic phase, which occurred at 28°C, 25% DM, and 52% initial concentration at 3 ml/kg. Discussion: These findings confirm that A. pasteurianus plays a critical role in reducing the aerobic stability of whole-plant corn silage. Additionally, the study identifies the optimal conditions that favor the proliferation of A. pasteurianus, offering valuable insights for the development of strategies to prevent and control this bacterium, thereby improving the aerobic stability of silage in hot and humid regions.

Opposing effects of warming on the stability of above- and belowground productivity in facing an extreme drought event.

Climate warming, often accompanied by extreme drought events, could have profound effects on both plant community structure and ecosystem functioning. However, how warming interacts with extreme drought to affect community- and ecosystem-level stability remains a largely open question. Using data from a manipulative experiment with three warming treatments in an alpine meadow that experienced one extreme drought event, we investigated how warming modulates resistance and recovery of community structural and ecosystem functional stability in facing with extreme drought. We found warming decreased resistance and recovery of aboveground net primary productivity (ANPP) and structural resistance but increased resistance and recovery of belowground net primary productivity (BNPP), overall net primary productivity (NPP), and structural recovery. The findings highlight the importance of jointly considering above- and belowground processes when evaluating ecosystem stability under global warming and extreme climate events. The stability of dominant species, rather than species richness and species asynchrony, was identified as a key predictor of ecosystem functional resistance and recovery, except for BNPP recovery. In addition, structural resistance of common species contributed strongly to the resistance changes in BNPP and NPP. Importantly, community structural resistance and recovery dominated the resistance and recovery of BNPP and NPP, but not for ANPP, suggesting the different mechanisms underlie the maintenance of stability of above- versus belowground productivity. This study is among the first to explain that warming modulates ecosystem stability in the face of extreme drought and lay stress on the need to investigate ecological stability at the community level for a more mechanistic understanding of ecosystem stability in response to climate extremes.

Comparative physiological and transcriptomic analyses reveal genotype specific response to drought stress in Siberian wildrye (Elymus sibiricus).

Siberian wildrye (Elymus sibiricus) is a xero-mesophytic forage grass with high nutritional quality and stress tolerance. Among its numerous germplasm resources, some possess superior drought resistance. In this study, we firstly investigated the physiological differences between the leaves of drought-tolerant (DT) and drought-sensitive (DS) genotypes under different field water contents (FWC) in soil culture. The results showed that, under drought stress, DT maintained a lower leaf water potential for water absorption, sustained higher photosynthetic efficiency, and reduced oxidative damage in leaves by efficiently maintaining the ascorbic acid-glutathione (ASA-GSH) cycle to scavenge reactive oxygen species (ROS) compared to DS. Secondly, using RNA sequencing (RNA-seq), we analyzed the gene expression profiles of DT and DS leaves under osmotic stress of hydroponics induced by PEG-6000. Through differential analysis, we identified 1226 candidate unigenes, from which we subsequently screened out 115/212 differentially expressed genes (DEGs) that were more quickly induced/reduced in DT than in DS under osmotic stress. Among them, Unigene0005863 (EsSnRK2), Unigene0053902 (EsLRK10) and Unigene0031985 (EsCIPK5) may be involved in stomatal closure induced by abscisic acid (ABA) signaling pathway. Unigene0047636 (EsCER1) may positively regulates the synthesis of very-long-chain (VLC) alkanes in cuticular wax biosynthesis, influencing plant responses to abiotic stresses. Finally, the contents of wax and cutin were measured by GC-MS under osmotic stress of hydroponics induced by PEG-6000. Corresponding to RNA-seq, contents of wax monomers, especially alkanes and alcohols, showed significant induction by osmotic stress in DT but not in DS. It is suggested that limiting stomatal and cuticle transpiration under drought stress to maintain higher photosynthetic efficiency and water use efficiency (WUE) is one of the critical mechanisms that confer stronger drought resistance to DT. This study provides some insights into the molecular mechanisms underlying drought tolerance in E. sibiricus. The identified genes may provide a foundation for the selection and breeding of drought-tolerant crops.

The role of sleep quality and anxiety symptoms in the association between childhood trauma and self-harm attempt: A chain-mediated analysis in the UK Biobank.

BACKGROUND: Childhood trauma is a risk factor for self-harm/suicidal behavior, but research on the potential association linking sleep quality and anxiety symptoms to childhood trauma and self-harm attempt is limited. The aim of this study was to describe the mediating role of sleep quality and anxiety symptoms between childhood trauma and self-harm attempt, and to provide a scientific basis for the prevention of self-harm behaviors. METHODS: This study ultimately included 11,063 study participants who participated in the baseline survey of this large prospective cohort study of the UK Biobank. We used structural equation modeling (SEM) to analyze the chain mediating role of sleep quality and anxiety symptoms in childhood trauma and self-harm attempt while controlling for covariates. RESULTS: A total of 19.58 % of study participants self-reported self-harm attempt. Sleep quality was negatively correlated with childhood trauma, anxiety symptoms, and self-harm attempt (p < 0.01). Childhood trauma, anxiety symptoms, and self-harm attempt were positively correlated (p < 0.01). In addition, after adjusting for confounders, anxiety symptoms were able to partially mediate the association between childhood trauma and self-harm attempt (effect value: 0.042, p < 0.01), and sleep quality and anxiety symptoms can chain mediate the association between childhood trauma and self-harm attempt (effect value:0.002, p < 0.01), with a total mediating effect of 65.67 % of the total effect. Subgroup analyses further showed that the mediating effects of sleep quality and anxiety symptoms on childhood trauma and self-harm attempt differed across age, gender, ethnicity, and smoking and drinking subgroups. CONCLUSIONS: This study found a complex relationship between childhood trauma, sleep quality, anxiety symptoms, and self-harm attempt, with sleep quality and anxiety symptoms mediating the relationship between childhood trauma and self-harm attempt. Multiple avenues of intervention, such as the provision of professional psychological interventions and timely monitoring, should be used to improve the sleep quality and mental health of individuals with traumatic childhood experiences and to prevent the occurrence of emotionally harmful behaviors such as self-harm/suicide.

Plant height as an indicator for alpine carbon sequestration and ecosystem response to warming.

Growing evidence indicates that plant community structure and traits have changed under climate warming, especially in cold or high-elevation regions. However, the impact of these warming-induced changes on ecosystem carbon sequestration remains unclear. Using a warming experiment on the high-elevation Qinghai-Tibetan Plateau, we found that warming not only increased plant species height but also altered species composition, collectively resulting in a taller plant community associated with increased net ecosystem productivity (NEP). Along a 1,500 km transect on the Plateau, taller plant community promoted NEP and soil carbon through associated chlorophyll content and other photosynthetic traits at the community level. Overall, plant community height as a dominant trait is associated with species composition and regulates ecosystem C sequestration in the high-elevation biome. This trait-based association provides new insights into predicting the direction, magnitude and sensitivity of ecosystem C fluxes in response to climate warming.

Effects of Climatic Change on Phylogeography and Ecological Niche of the Endemic Herb Elymus breviaristatus on the Qinghai-Tibet Plateau.

Past climatic and topographic variations have created strong biogeographic barriers for alpine species and are key drivers of the distribution of genetic variation and population dynamics of species on the Qinghai-Tibet Plateau (QTP). Therefore, to better conserve and use germplasm resources, it is crucial to understand the distribution and differentiation of genetic variation within species. Elymus breviaristatus, an ecologically important rare grass species with strong resistance, is restricted to a limited area of the QTP. In this study, we investigated the phylogeography of E. breviaristatus using five chloroplast genes and spacer regions in natural populations distributed along the eastern QTP. We identified a total of 25 haplotypes among 216 individuals from 18 E. breviaristatus populations, which were further classified into four haplogroups based on geographical distribution and haplotype network analysis. Notably, we did not observe any signs of population expansion. High genetic diversity was exhibited at both species and population levels, with precipitation being the main limiting factor for population genetic diversity levels. Higher genetic diversity was exhibited by populations located near the Mekong-Salween Divide genetic barrier, suggesting that they may have served as a glacial refuge. The significant pattern of genetic differentiation by environmental isolation highlights the influence of heterogeneous environments on the genetic structure of E. breviaristatus populations. Additionally, the results of ecological niche models indicated that the geographic distribution of E. breviaristatus populations has decreased rapidly since the Last Glacial Maximum but is not threatened by future global warming.

Genome-wide identification and characterization of abiotic stress responsive GRAS family genes in oat (Avena sativa).

Background: GRAS transcription factors play a variety of functions in plant growth and development and are named after the first three transcription factors GAI (GIBBERRELLICACIDINSENSITIVE), RGA (REPRESSOROFGAI), and SCR (SCARECROW) found in this family. Oat (Avena sativa) is one of the most important forage grasses in the world. However, there are few reports on the GRAS gene family in oat. Methods: In order to understand the information and expression pattern of oat GRAS family members, we identified the GRAS members and analyzed their phylogenetic relationship, gene structure, and expression pattern in oat by bioinformatics technology. Results: The results showed that the oat GRAS family consists of 30 members, and most of the AsGRAS proteins were neutral or acidic proteins. The phylogenetic tree divided the oat GRAS members into four subfamilies, and each subfamily has different conservative domains and functions. Chromosome location analysis suggested that 30 GRAS genes were unevenly distributed on five chromosomes of oat. The results of real-time quantitative reverse transcription-PCR (qRT-PCR) showed that some AsGRAS genes (AsGRAS12, AsGRAS14, AsGRAS21, and AsGRAS24) were all up-regulated with increasing stress treatment time.The results of this study provide a theoretical basis for further research into the corresponding stress of oat. Therefore, further studies concentrating on these AsGRAS genes might reveal the many roles played by GRAS genes in oat.