The effect of abiotic stresses on plant C:N:P homeostasis and their mitigation by silicon

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus(C:N:P), leading to biochemical and physiological alterations and reductions in yield. Silicon(Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources(water, light, nutrients, and toxic elements), strategically employ Si to maintain C:N:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating C:N:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on C:N:P homeostasis, as well as the role of Si in preserving C:N:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining C:N:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation.

Resistance mechanisms and reprogramming of microorganisms for efficient biorefinery under multiple environmental stresses

In the fermentation process of biorefinery,industrial strains are normally subjected to adverse environmental stresses,which leads to their slow growth,yield decline,a substantial increase in energy consumption,and other negative consequences,which ultimately seriously hamper the development of biorefinery.How to minimize the impact of stress on microorganisms is of great significance.This review not only reveals the damaging effects of different environmental stresses on microbial strains but also introduces commonly used strategies to improve microbial tolerance,including adaptive evolution,reprogramming of the industrial host based on genetic circuits,global transcription machinery engineering(gTME)and bioprocess integration.Furthermore,by integrating the advantages of these strategies and reducing the cost of system operation,the tolerance of industrial strains,combined with production efficiency and process stability,will be greatly improved,and the development prospects of biorefinery will be more widespread.

Lipidomics in archaeal membrane adaptation to environmental stresses and growth conditions:A review of culture-based physiological studies

Membrane lipids are thought to be a crucial part of the homeoviscous adaptation of archaea to extreme conditions.This article reviews the recent lipidomic studies of physiological membrane adaptations of archaea,assesses the biomolecular basis of an organic paleothermometer,TEX86,and contemplates the future directions of archaeal lipidomics.The studies of extremophilic archaea have revealed that at least three different molecular mechanisms are involved in membrane adaptation of archaea:(1)regulation of the number of cyclopentane rings of caldarchaeol,(2)alteration of the diether-to-tetraether lipid ratio,and(3)variation of the proportion of saturated and unsaturated lipids.However,most of the studies have focused on a limited number of archaeal ether-linked lipids,such as glycerol dialkyl glycerol tetraethers(GDGTs),which only represent a fraction of the entire lipidome.Environmental factors such as growth temperature and pH have been most frequently reported,but biotic factors,including growth phases,nutrition,and enzymatic activities affecting the membrane lipid composition are often overlooked.Membrane lipids of mesophilic ammonia-oxidizing marine Thaumarchaeota have been applied in the reconstruction of past sea surface temperatures.However,recent culture-based physiological studies have demonstrated that non-thermal biotic factors,including dissolved oxygen,ammonia oxidation rate and the growth rate,are the main drivers of GDGT cyclization in Nitrosopumilus maritimus.Moreover,other related strains or ecotypes exhibit a markedly different set of stress adaptations.A trend is now developing to examine the whole lipid profile(lipidome)for studies of archaeal physiology and biochemistry related to lipid biosynthesis(lipidomics)to gain a better understanding of the biological mechanisms underpinning the applications of membrane lipid-based proxies in biogeochemical or ecological research.

Contributions of aversive environmental stress to migraine chronification:Research update of migraine pathophysiology

Clinical studies have suggested that internal and/or external aversive cues may produce a negative affective-motivational component whereby maladaptive responses(plasticity)of dural afferent neurons are initiated contributing to migraine chronification.However,pathophysiological processes and neural circuitry involved in aversion(unpleasantness)-producing migraine chronification are still evolving.An interdisciplinary team conducted this narrative review aimed at reviewing neuronal plasticity for developing migraine chronicity and its relevant neurocircuits and providing the most cutting-edge information on neuronal mechanisms involved in the processing of affective aspects of pain and the role of unpleasantness evoked by internal and/or external cues in facilitating the chronification process of migraine headache.Thus,information presented in this review promotes the understanding of the pathophysiology of chronic migraine and contribution of unpleasantness(aversion)to migraine chronification.We hope that it will bring clinicians’attention to how the maladaptive neuroplasticity of the emotion brain in the aversive environment produces a significant impact on the chronification of migraine headache,which will in turn lead to new therapeutic strategies for this type of pain.

Research Progress on Lonicera japonica Thunb.Affected by Environmental Stress

Lonicera japonica Thunb.is widely distributed in China.It has strong adaptability to the environment and can maintain normal growth and development under a variety of stress conditions.It is commonly used as a medicine with its dry flower buds or newly opened flowers,named honeysuckle,and with both economic value and ecological application value.The research progress of L.japonica Thunb.under stress conditions such as temperature,drought,light,salt,heavy metals and diseases,pests and endophytic bacteria was reviewed,and the current research situation of the physiological and biochemical response mechanism,changes of photosynthetic fluorescence and accumulation of secondary metabolites of honeysuckle under different stresses was discussed,so as to provide a reference for deep-level exploring the resistance mechanism of L.japonica Thunb.in the future and lay a theoretical foundation for the high-quality authentic ecological cultivation of L.japonica Thunb.

The Role of Environmental Stress in Determining Gut Microbiome:Case Study of Two Sympatric Toad-headed Lizards

The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or environment(environmental factor).In this study,we investigated the gut microbial communities and potential functional signatures of two sympatric species distributed along an elevation gradient,the toadheaded lizards Phrynocephalus axillaris and P.forsythii.Our results indicated that at high elevations,the gut microbial communities of P.axillaris and P.forsythii did not significantly differ,and the phylogenetic relationships of gut microbial communities contradicted their hosts.At low altitudes,the two lizards could be distinguished based on their significantly different gut microbial communities.Compared to low-altitude populations,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that at higher altitudes,energy metabolism,such as carbohydrate,lipid,and amino acids metabolism were higher in both lizards.While a larger number of pathogenic bacteria were found in the lowaltitude population of P.forsythii.This suggests that the convergence of gut microbiota of two lizards at highaltitude stem from environmental factors,as they were exposed to the same environmental stress,whereas the divergence at low-altitude stemmed from heritable factors,as they were exposed to different environmental stresses.These results provide a new perspective regarding whether heritable or environmental factors dominate the gut microbiota during exposure to environmental stress.

Seedling’s Vigor of Tomato and Paprika Genotypes under a Simulated Model of Multiple Abiotic Stresses and Lower Dosage of Salicylic Acid (C7H6O3)

Seedling vigor in tomato and paprika is affected by variety. Genotype selection under environmental stresses and its effects on seedling vigor was investigated. During the year 2021, the study was carried out and it revealed an appropriate selection for open field gardeners. The selection of two drought-tolerant, and one non-drought tolerant cultivars was the initial stage. Six commercial genotypes were evaluated (three for tomato and three for paprika). The second phase involved planting cultivars till the cotyledon leaves phase, and the first set of true leaves. Seedlings were investigated under simulated environmental stresses of non-ideal temperatures, low humidity, closed spacing, minimum light dose, nutrient-deficient water, and spraying a lower dosage of salicylic acid. The evaluation of seedling’s growth was performed by measuring germination percentage, seedling length, shoot length, root length, seedling fresh weight, seedling dry weight, and seedling vigor index. Tomato (Mobil) and paprika (Carma) seedlings outperform other varieties, possibly because of the variety’s vigor under various stress conditions. These findings reveal that tomato (Mobil) and paprika (Carma) had a positive impact on development and may be raised under optimal conditions of nurseries and then be transferred to open-air environmental and biological exposed conditions in Hungary.

Roles of ABA Signal Transduction during Higher Plant Seed Development and Germination

ABA is one of the 5 phytohormones in higher plants, which is also the most important hormone that regulates higher plants in response to environmental stress, by ABA signal transduction. Understanding ABA signal transduction at the molecular level is crucial to biology and ecology, and rational breeding complied with corresponding eco-environmental changes. Great advancements have taken place over the past 10 years by application of the Arabidopsis experimental system. Many components involved in ABA signal transduction have been isolated and identified and a clear overall picture of gene expression and control for this transduction has become an accepted fact. On the basis of the work in our laboratory, in conjunction with the data available at the moment, the authors have attempted to integrate ABA signal transduction pathways into a common one and give some insights into the relationship between ABA signal transduction and other hormone signal transduction pathways, with an emphasis upon the ABA signal transduction during higher plant seed development. A future challenge in this field is that different experimental systems are applied and various receptors and genes need to be characterized through the utilization of microarray chips.

The rise and fall of photosynthesis:hormetic dose response in plants

The recent recognition that low doses of herbicides,human and veterinary antibiotics,metallic elements,micro/nano-plastics,and various other types of environmental pollutants widely enhance chlorophylls in the framework of hormesis created the need to further evaluate the response of photosynthetic pigments and gas exchange to low doses of stresses.An analysis of about 370 values of maximum stimulatory response(MAX;percentage of control response,%)of chlorophylls in higher plants,algae and duckweeds,and other photosynthesizing organisms,mined from published literatures,revealed a greater MAX for higher plants(median=139.2%)compared to algae and duckweeds(median=119.6%).However,an analysis of about 50 mined values of MAX of carotenoids revealed no signifi-cant difference in the median MAX between higher plants(median=133.0%)and algae-duckweeds(median=138.1%).About 70 mined values of MAX were also concentrated for photosynthetic rate(median MAX=129.2%)and stomatal conductance(median MAX=124.7%)in higher plants.Within higher plants,there was no significant difference in the median MAX among chlorophylls,carotenoids,photosynthetic rate,and stomatal conductance.Similarly,there was no significant difference in the median MAX between chlorophylls and carotenoids of pooled algae and duckweeds.The results suggest that the MAX is typically below 160%and as a rule below 200%of control response,and does not differ among chlorophylls,carotenoids,photosynthetic rate,and stomatal conductance.New research programs with improved experimental designs,in terms of number and spacing of doses within the“low-dose zone”of the hormetic dose–response relationship,are needed to study the molecular/genetic mechanisms underpinning the low-dose stimulation of photosynthesis and its ecological implications.

The Combined Effect of Plastic Particles Size and Concentration on Rotifers’ (Brachionus plicatilis) Performance

The presence of microplastics in aquatic ecosystems is of increasing global concern.Nano-sized plastics,in particular,can penetrate the cell membrane and cause biological death.Our study evaluated the combined impacts of several polystyrene mi-crospheres’sizes and nominal concentrations on the overall performance changes of Brachionus plicatilis.Experimental animals were exposed to three microplastic sizes(0.08,0.5 and 6μm)and five nominal concentrations(0,0.5,2,8,32μg mL−1)for 20 d.Our results showed that the toxicological effect of particle size on rotifers did not significantly depend on the nominal concentration.The interaction between the nominal concentration and size occurred only for body length and lorica width.Specifically,high nominal concentrations of microplastics that were close to nanometer size significantly impaired the overall vitality of rotifers,embodied in shortage of body type,delay in the arrival of maturity,reduction in the cumulative number of neonates,and the advance of the death process.In comparison,fair-sized size(0.5 and 6μm)displayed non-significant damage except for individual groups.Most notably,the net reproductive yield was only a third of what it was in the original environment,implying that there was not much fertility left.Besides,with the development of rotifers,the adverse effects of polystyrene microsphere drive had become more and more serious.

Physiological Characteristics of Nitzschia hantzschia in Response to Nitrobenzene Stress

This study was conducted to investigate the effects of different mass concentrations of nitrobeneze on the growth, soluble sugar content, soluble protein content, chlorophyll a content and algal cell conductivity of Nitzschia hantzschia. The results showed that as the concentration of nitrobenzene increased, the growth of N. hantzschia was inhibited, and the algal culture liquids gradually changed from dark yellow to light yellow after 5 d of treatment;the soluble sugar content increased after 2 d;and the soluble protein content of the 100 mg/L nitrobenzene treatment group was 89.1% of the control group on day 1, which was the lowest value, and then showed a gradual upward trend. The low-mass concentration of nitrobenzene promoted the chlorophyll a content of algal cells, the medium and high mass concentrations had an inhibitory effect, and the chlorophyll a content of the 50 mg/L treatment gradually recovered after 3 d. The electrical conductivity of algal cells gradually increased with the increase of the mass concentration of nitrobenzene. The electrical conductivity gradually recovered after 3 d of the low mass concentration treatment, while the high mass concentration harmed the algae cells, causing N. hantzschia to gradually die.

Dieback intensity but not functional and taxonomic diversity indices predict forest productivity in different management conditions: Evidence from a semi-arid oak forest ecosystem

The relationships between different aspects of diversity(taxonomic,structural and functional)and the aboveground biomass(AGB)as a major component of global carbon balance have been studied extensively but rarely under the simultaneous influence of forest dieback and management.In this study,we investigate the relationships between taxonomic,functional and structural diversity of woody species(trees and shrubs)and AGB along a gradient of dieback intensity(low,moderate,high and no dieback as control)under two contrasted management conditions(protection by central government vs.traditional management by natives)in a semi-arid oak(Quereus brantii Lindl.)forest ecosystem.AGB was estimated and taxonomic diversity,community weighted average(CWM)and functional divergence indices were produced.We found that the aerial biomass was significantly higher in the intensively used area(14.57(±1.60)t/hm^(2))than in the protected area(8.70(±1.05)t/hm^(2))due to persistence of some large trees but with decreasing values along the dieback intensity gradient in both areas.CWM of height(H),leaf nitrogen content(LNC)and leaf dry matter content(LDMC)were also higher in the traditional managed area than in the protected area.In contrast,in the protected area,the woody species diversity was higher and the inter-specific competition was more intense,explaining a reduced H,biomass and LDMC.Contrary to the results of CWM,none of the functional diversity traits(FDvar)was affected by dieback intensity and only FDvar values of LNC,leaf phosphorus content(LPC)and LDMC were influenced by management.We also found significantly positive linear relationships of AGB with CWM and FDvar indices in the protected area,and with taxonomic and structural diversity indices in the traditional managed area.These results emphasize that along a dieback intensity gradient,the leaf functional traits are efficient predictors in estimating the AGB in protected forests,while taxonomic and structural indices provide better results in forests under a high human pressure.Finally,species identity of the dominant species(i.e.,Brant’s oak)proves to be the main driver of AGB,supporting the selection effect hypothesis.

Diversity of Saxicolous Lichens along an Aridity Gradient in Central México

Lichens are symbiotic organisms that comprise a fungus and a photosynthetic partner wich are recognized as a good indicator of climate change.However,our understanding of how aridity affects the diversity of saxicolous lichens in drylands is still limited.To evaluate the relationship between saxicolous lichen diversity and aridity in a central México dryland,a geographical transect was established of 100 km to build an aridity gradient in the semiarid zone of the State of Querétaro,Mexico,comprising ten sampling sites with a 10 km separation.Species richness,abundance and diversity of soil lichen species were recorded using two sampling methods:the quadrat-intercept and the line-intercept method,to compare their performance in assessing soil lichen diversity in drylands.The number of species and Shannon diversity of saxicolous lichens were higher at intermediate values of the aridity index(AI=0.10-0.34).Quadrat intercept and point intercept methods gave quite similar results,which means that the selected method does not influence the results in a significant way.This study confirms the role of saxicolous lichens as climate change indicators and reveals the importance of the sampling method selection in the evaluation of different parameters of soil lichen diversity in drylands.

Alternative models for transgenerational epigenetic inheritance:Molecular psychiatry beyond mice and man

Mental illness remains the greatest chronic health burden globally with few inroads having been made despite significant advances in genomic knowledge in recent decades.The field of psychiatry is constantly challenged to bring new approaches and tools to address and treat the needs of vulnerable individuals and subpopulations,and that has to be supported by a continuous growth in knowledge.The majority of neuropsychiatric symptoms reflect complex geneenvironment interactions,with epigenetics bridging the gap between genetic susceptibility and environmental stressors that trigger disease onset and drive the advancement of symptoms.It has more recently been demonstrated in preclinical models that epigenetics underpins the transgenerational inheritance of stressrelated behavioural phenotypes in both paternal and maternal lineages,providing further supporting evidence for heritability in humans.However,unbiased prospective studies of this nature are practically impossible to conduct in humans so preclinical models remain our best option for researching the molecular pathophysiologies underlying many neuropsychiatric conditions.While rodents will remain the dominant model system for preclinical studies(especially for addressing complex behavioural phenotypes),there is scope to expand current research of the molecular and epigenetic pathologies by using invertebrate models.Here,we will discuss the utility and advantages of two alternative model organisms–Caenorhabditis elegans and Drosophila melanogaster-and summarise the compelling insights of the epigenetic regulation of transgenerational inheritance that are potentially relevant to human psychiatry.

Effects of Irrigation and Drought on Growth and Essential Oil Production in O. vulgare and R. officinalis

The essential oil industry has led a rapidly growing market in American herbal medicine. The global essential oil industry was valued at an estimated 18.6 billion USD in 2020 and is expected to have a compound annual growth rate of 7.6% from 2020 to 2027. “Essential oil” is a broad term used to describe volatile organic compounds (VOCs) that are often associated with a plant’s essence or aroma. These molecules are commonly extracted from a variety of different plant structures by steam distillation and cold pressing. Essential oils function as a defense against insects, bacteria, fungi, and other stressors, such as drought and cold. The most industrially important of this class of compounds are monoterpenes, steam-volatile constituents which are the most abundant terpenes throughout plants. Essential oils may include monoterpenes (two isoprene units), sesquiterpenes (three isoprene units), ketones, and phenolics. Phenolics include flavonoids, anthocyanins, and tannins.

Genetic Diversity of Local Rice Accessions Cultivated in Guinea Based on Agro-Morphological Traits and Identification of Sources of Tolerance to Iron Toxicity

In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to iron toxicity poses a serious threat to the preservation of the genetic resources of these traditional varieties, whose genetic diversity remains poorly known. The present study therefore aims at a better valorisation of these local rice cultivars through the evaluation of their agromorphological diversity and the identification of genotypes potentially tolerant or resistant to iron toxicity. Thus, 90 accessions collected in the regions of Kindia and Macenta and six controls susceptible or resistant to iron toxicity (AZUCENA, BOUAKE 189, CK 73, IR64, NERICAL 19 and AURYLUX 6) were evaluated in three replicate alpha lattice designs in two sites (Sérédou and Kilissi) using 16 agromorphological traits. The results showed significant agromorphological variability of the traditional accessions at both sites for all qualitative and most quantitative traits studied. In addition, 30 local cultivars expressed similar or higher grain yields than the resistant or tolerant controls at both sites, of which 12 were found to be stable at both sites. Of the 12 cultivars identified, five were resistant and seven tolerant to iron toxicity. These 12 accessions could be used in the varietal improvement of lowland rice in Guinea Conakry.

The ubiquitin codes in cellular stress responses

Ubiquitination/ubiquitylation,one of the most fundamental post-translational modifications,regulates almost every critical cellular process in eukaryotes.Emerging evidence has shown that essential components of numerous biological processes undergo ubiquitination in mammalian cells upon exposure to diverse stresses,from exogenous factors to cellular reactions,causing a dazzling variety of functional consequences.Various forms of ubiquitin sig-nals generated by ubiquitylation events in specific milieus,known as ubiquitin codes,constitute an intrinsic part of myriad cellular stress responses.These ubiquitination events,leading to proteolytic turnover of the substrates or just switch in functionality,initiate,regulate,or supervise multiple cellular stress-associated responses,supporting adaptation,homeostasis recovery,and survival of the stressed cells.In this review,we attempted to summarize the crucial roles of ubiquitination in response to different environmental and intracellular stresses,while discussing how stresses modulate the ubiquitin system.This review also updates the most recent advances in understanding ubiquitination machinery as well as different stress responses and discusses some important questions that may warrantfutureinvestigation.

Integrative regulatory mechanisms of stomatal movements under changing climate

Global climate change-caused drought stress,high temperatures and other extreme weather profoundly impact plant growth and development,restricting sustainable crop production.To cope with various environmental stimuli,plants can optimize the opening and closing of stomata to balance CO_(2)uptake for photosynthesis and water loss from leaves.Guard cells perceive and integrate various signals to adjust stomatal pores through turgor pressure regulation.Molecular mechanisms and signaling networks underlying the stomatal movements in response to environmental stresses have been extensively studied and elucidated.This review focuses on the molecular mechanisms of stomatal movements mediated by abscisic acid,light,CO_(2),reactive oxygen species,pathogens,temperature,and other phytohormones.We discussed the significance of elucidating the integrative mechanisms that regulate stomatal movements in helping design smart crops with enhanced water use efficiency and resilience in a climate-changing world.

Leaf developmental stability of Platanus acerifolia under urban environmental stress and its implication as an environmental indicator

The developmental stability indices,leaf width based fluctuating asymmetry(FA1),and lateral vein length based directional asymmetry(RDA1)of Platanus acerifolia were studied.All the leaves were sampled from 14 sites that were categorized based on different urban environmental stress levels(UESL)in Shanghai metropolitan,China.Besides,foliar stomatal density and stomatal length were also studied as the subsidiary indices to test the availability of developmental stability indices as the indicator under a stressful environment.Results showed seasonal variation of FA1 and RDA1 existed among the 14 sites,but the data showed significant negative correlation between FA1 and UESL(FA1=0.029−0.0009UESL+0.0003UESL2,r=0.7665,P=0.0014).However,a similar trend was not found between RDA1 and UESL.Furthermore,the significant correlation among FA1 and leaf stomatal length and stomatal density implied they could be used as indicators of urban stress levels on a small scale.It seemed that RDA1 was possibly a normal parameter during leaf development but it was unavailable for use as an indicator of urban stresses.