Combined Effect Of Stress Research Articles

Protective Effect of 24-Epibrassinolide on Barley Plants Growing Under Combined Stress of Salinity and Potassium Deficiency

Evaluation of the effects of 24-epibrassinoide (24-EBL) was done on two genotypes of barley (Hordeum vulgare L.) plants (salt tolerant-RD-2508 and salt sensitive-RD-2660) grown under combined stress of salinity and potassium deficiency. Salt-stressed (200 mM NaCl) and K-deficient plants were subjected to different concentrations of 24-EBL (1 ppm, 100 ppm, 1000 ppm) to analyse its effect on combinatorial abiotic stress. Individually both salinity stress and potassium deficit resulted in decrease of plant growth, chlorophyll content and relative water content (RWC). However, the combination of salinity stress and potassium deficient was found to be more harmful for plants. Supplementation of 24-EBL ameliorated the negative effects of combined stress and promoted the growth of stressed plants. This ameliorative effect of 24-EBL could be accounted by the improved activity of antioxidant enzymes, osmolytes such as proline and sugar that affected the oxidative stress by reducing Na+ accumulation and improved K+ concentration and K+/Na+ ratio in stressed plants. Enhancement of K+ accumulation and increase in K+/Na+ ratio through restriction of Na+ accumulation could be considered as a key feature for 24-EBL-induced tolerance along with improved RWC and chlorophyll content. 24- EBL at 100 ppm was more promising in alleviating the stress conditions. Thus, BR-induced manipulation in ion haemostasis can be a prominent trait and can be used as a criterion for developing salt stress and K-limited tolerant barely genotypes.

Influence and mechanism of stress combination on medicinal plants secondary metabolism

Numerous studies showed that the growth of medicinal plants in their native areas was simultaneously affected by abiotic stress combinations. Compared with single stress, plants have unique responses to a combination of different abiotic stresses and cannot be inferred directly from plants' responses to each individual stress. The effect of combined stresses on plants usually has three types of synergistic antagonism or independence. The secondary metabolism in the process of medicinal plant stress combination response also played a vital role, and environmental stresses can spur the accumulation of secondary metabolites, but under the stress combination, plants induce specific gene expression of key enzymes on secondary metabolic pathways, in turn, the accumulation of secondary metabolites against stress is formed. When plants are subjected to stress combination, the interaction of multiple signaling pathways makes it highly complex for plants to respond to stress combination. This paper summarized the effects of stress combination on physiological and secondary metabolism of medicinal plants, and discussed the related physiological, biochemical and molecular mechanisms. It provides theoretical basis for improving the adaptability of medicinal plants to adversity, improving the quality of Chinese medicinal materials, and further optimizing the cultivation of medicinal plants.

Strong earthquake clustering around the eastern Tibetan Plateau after the 2008 MW7.9 Wenchuan earthquake

After the 2008 MW7.9 Wenchuan earthquake, the eastern Tibetan Plateau experienced a series of MW>6.0 earthquakes, including the 2013 MW6.6 Lushan, 2014 MW6.1 Kangding and 2017 MW6.5 Jiuzhaigou events. Based on available constraints, we build a three-dimensional viscoelastic finite element model to calculate Coulomb failure stress caused by these strong earthquakes. In this model, the geometry and slip vector of the initial rupture zone of each earthquake are used to better evaluate the earthquake-related stress projection. Considering reasonable ranges of viscosities for the crust and upper mantle in different tectonic units, numerical results show that after the Wenchuan earthquake, the coseismic Coulomb failure stress change at the hypocenters of the subsequent earthquakes increased to approximately +0.012–+0.040, +0.01–+0.03, and +0.008–+0.015 MPa, respectively. With viscoelastic relaxation of the lower crust and upper mantle, the Coulomb failure stress change at the hypocenters of these earthquakes accumulated to about +0.014–+0.042, +0.016–+0.036, and +0.003–+0.007 MPa just before their occurrence. This suggests that the Wenchuan earthquake indeed triggered or hastened the occurrence of the Lushan, Kangding and Jiuzhaigou events, supporting that strong earthquake clustering around the eastern Tibetan Plateau could be related to stress interaction between the seismogenic faults. Besides, ~94% and ~6% of the stress increase around (and before the occurrence of) the Kangding earthquake were contributed by the Wenchuan event and the Lushan event, respectively; the positive Coulomb failure stress change at the Jiuzhaigou earthquake hypocenter was related to coseismic slip partitioning of the Wenchuan earthquake. This means that stress interaction among the earthquakes could be controlled by the combined effect of stress of the previous events and by the complexity of earthquake ruptures. Thus, in researches on the earthquake-triggering mechanism, special attentions should be paid on both details of the rupture model and multiple factors of previous earthquakes.

Single and Combined Effects of Cadmium and Aroclor 1254 on Oxidative Stress in Gills of Mytilus coruscus

Both polychlorinated biphenyls (PCBs) and cadmium (Cd) can be frequently found in marine ecosystems and have detrimental effects on marine organisms, especially on filter-feeding marine mussels. Although biological responses to single metal or PCB exposure in mussels have been well-studied, information about oxidative stress is still limited, especially in different tissues in mussels. Considering the variety of contaminants existing in the actual marine environment, the exposures of the marine mussel Mytilus coruscus to Cd2+ alone (0.194, 0.388, and 0.775 mg/L) and Aroclor 1254 alone (0.005, 0.010, and 0.050 mg/L) and the co-exposures of the marine mussel Mytilus coruscus to Cd2+ (0.194 and 0.388 mg/L) and Aroclor 1254 (0.005 and 0.010 mg/L) were tested in an 8-day exposure experiment followed by a 7-day acclimation experiment. The alterations in superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde levels in the gills of the mussels were assessed. The effects of the depressed antioxidant were induced by the exposures of Cd2+ and Aroclor 1254 and their co-exposures. All exposures resulted in an initial increase and then a reduction in antioxidant enzyme activities. The range and rate of the antioxidant enzyme activities were positively correlated with stress duration and the concentration of the stress material. The effect of combined stress was stronger than that of each individual stressor. The valuable information for future investigations of stress response mechanisms, especially in relation to tissue functions in marine organisms, has been provided by the results and experimental model. The study of combined pollution effects has more scientific significance for marine pollution monitoring.

ДИНАМИКА УРОВНЯ ЦИРКУЛИРУЮЩИХ ИММУННЫХ КОМПЛЕКСОВ В СЫВОРОТКЕ КРОВИ У КРОЛИКОВ ПРИ МОДЕЛЬНЫХ СТРЕССАХ

A small amount of circulating immune complexes is determined in a healthy body, and it naturally increases when there is an antigen in the circulation. Stressful situations can inhibit the implementation of immune protection, both adaptive and innate immune responses. The purpose of this study was to study the dynamics of the level of circulating immune complexes in blood serum after modeling single and combined stress effects in rabbits. 10 male rabbits were used for the experiment. The animals were 8 months old and had a live weight of 3.40±0.73 kg. Transport stress was caused by transporting animals in a car. Immobilization stress was modeled by fixing rabbits in a fixation de-vice for small animals by their legs in the dorsal position. In the final series of experi-ments, a combination of actions was per-formed (immobilization, then, after three days, transportation). As a result of studies it was found that the reaction of animals to stress was characterized by decreased level of the CIC, during transportation (by 1.2 times (p<0.05) and immobilization (1.6 times, p<0.05), the combination of stress factors showed a similar effect. In the post-stress period, we observed in all cases an increase in the CIC level in the blood of rab-bits, which exceeded the CIC values both at the time of the stress reaction and the level of intact animals.

Technological residual stresses during grinding of high-strength steels

The quality of parts made of high-strength steels is largely determined by the ability to perceive alternating cyclic loads. This ability depends on the sign and the level of technological stresses generated largely in the final operations. Residual stresses are the result of the combined effect of stresses from forces, temperatures, and structural transformations. A significant part of specialists in this field believe that the dominant factor in their formation is heat. Thermoplastic deformations and phase-structural transformations occur under the influence of cutting heat. There are tensile stresses that reduce the cyclic strength of parts. The aim of the work is to develop recommendations for providing on the surfaces of parts made of high-strength steels favorable residual stresses. For its implementation, a deep study of the known mechanisms of the formation of residual stresses is carried out, the process of chip formation during cutting with a cutter with a negative front angle is considered in depth, the role of the modified temperature, smoothing effect is revealed.

Determination of Crack-Tip Opening Displacement in T-Type Wedge Opening Loaded Specimen

The protective layer at the crack tip of an alloy component can be damaged, and the resistance to crack propagation can be reduced by the combined effects of stress and a corrosive environment. Therefore, the measurement of crack-tip opening displacement (CTOD) can be applied to characterize the crack propagation rate (da/dt) during stress corrosion cracking (SCC) experiments. In the present work, CTOD of a T-type wedge opening loaded (T-WOL) specimen with a built-in loading bolt was initially determined using three-dimensional elastic-plastic finite element analysis (FEA). The influence of stress concentration from side groove on CTOD was clearly evaluated, i.e., the fluctuation of CTOD occurred near the groove-tip plane. However, CTOD became stable on >90% of thickness of T-WOL specimen. Therefore, CTOD at mid-thickness plane of T-WOL specimen could be applied for SCC experiment.

Stress- and electric-field-induced band gap tuning in hexagonal boron phosphide layers

Two-dimensional hexagonal boron phosphide presents great potential in applications of electronics and optoelectronics due to its high carrier mobility and moderate band gap. In this work, we investigate the effect of stress and electric field on the electronic properties of hexagonal boron phosphide layers based on first-principles calculations. We find that both the band gap and the carrier effective masses of hexagonal boron phosphide monolayer gradually increase with stress from compression to tension. As for hexagonal boron phosphide bilayer with two stacking orders (AB_B-P and AB_B-B) upon applied electric field, the band gap monotonously increases with the enhancement of electric field for AB_B-P bilayer, while it undergoes a band gap closing and reopening process for AB_B-B bilayer. We employ the tight-binding model to explain the mechanism of different band gap variations of two stacking orders with electric field. Moreover, we discuss the band gap variation of hexagonal boron phosphide bilayer with combined effect of stress and electric field. The investigation here presents an insight into the effective manipulation towards the electronic properties of hexagonal boron phosphide, which will further enable the broader applications of the hexagonal boron phosphide in modern electronic and optoelectronic fields.

High-Throughput Screening of Chlorella Vulgaris Growth Kinetics inside a Droplet-Based Microfluidic Device under Irradiance and Nitrate Stress Conditions.

Biodiesel is an eco-friendly renewable fuel that can be derived from microalgae. Maximization of biomass and lipid productivities are considered the main challenges for algal biodiesel production. Since conventional batch cultures are time-, space-, and reagent-consuming with many restrictions to apply many replicates, microfluidic technology has recently emerged as an alternative low-cost and efficient technology with high throughput repeatability and reproducibility. Different applications of microfluidic devices in algal biotechnology have been reported, including cell identification, sorting, trapping, and metabolic screening. In this work, Chlorella vulgaris was investigated by encapsulating in a simple droplet-based micro-array device at different light intensities of 20, 80, and 200 µmol/m2/s combined with different nitrate concentrations of 17.6, 8.8, and 4.4 mM. The growth results for C. vulgaris within microfluidic device were compared to the conventional batch culture method. In addition, the effect of combined stress of deficiencies in irradiance and nitrogen availability were studied to illustrate their impact on the metabolic profiling of microalgae. The results showed that the most optimum favorable culturing conditions for Chlorella vulgaris growth within the microfluidic channels were 17.6 mM and 80 µmol/m2/s.

Stress Corrosion of Bridge Cable Wire by the Response Surface Method

The combined effect of stresses and three environmental factors of temperature, Cl concentration and pH of a corrosive solution on the corrosion rate of bridge cable wires was investigated by stress corrosion test based on the response surface method. The stresses corrosion rate of wires is measured by the electrode polarization method using a newly-developed loading device. The relation between the corrosion rate and stresses of wires is obtained. The actual corrosion rate affected by various environmental factors (temperature, acid rain, and chloride content in air) is fitted with a response surface function. The efficiency of several functions was compared followed by significance analysis of a chosen one. The combined effect of environmental factors and stresses on the corrosion rate of wires is evaluated. As stresses increase, the corrosion rate of wires speeds up with progressive acceleration, the four factors can be arranged in descending order as to their effect on the corrosion rate of wires pH of a corrosive solution, temperature, stresses, and Cl concentration; common effect should stem from the ir combination and the range of environmental factors.

Integrative roles of nitric oxide and hydrogen sulfide in melatonin-induced tolerance of pepper (Capsicum annuum L.) plants to iron deficiency and salt stress alone or in combination.

There seems to be no report in the literature on the effect of melatonin (MT) in relieving the detrimental effects of combined application of salt stress (SS) and iron deficiency (ID). Therefore, the effect of MT on the accumulation/synthesis of endogenous nitric oxide (NO) and hydrogen sulphide (H2 S) and how far these molecules are involved in MT-improved tolerance to the combined application of ID and SS in pepper (Capsicum annuum L) were tested. Hence, two individual trials were set up. The treatments in the first experiment comprised: Control, ID (0.1 mM FeSO4 ), SS (100 mM NaCl) and ID + SS. The detrimental effects of combined stresses were more prominent than those by either of the single stress, with respect to growth, oxidative stress and antioxidant defense attributes. Single stress or both in combination improved the endogenous H2 S and NO, and foliar-applied MT (100 µM) led to a further increase in NO and H2 S levels. In the second experiment, 0.1mM scavenger of NO, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO) and that of H2 S, hypotuarine (HT) were applied along with MT to get further evidence whether NO and H2 S are involved in MT-induced tolerance to ID and SS. MT combined with cPTIO and HT under a single or combined stress showed that NO effect was reversed by the NO scavenger, cPTIO, alone but the H2 S effect was inhibited by both scavengers. These findings suggested that tolerance to ID and SS induced by MT may be involved in downstream signal crosstalk between NO and H2 S.

Effect of combined stress (salinity + hypoxia) and auxin rooting hormone addition on morphology and growth traits in six Salix spp. clones

Willows plantations development could be an alternative for hydro-halomorphic soils but it is limited by combined stress salinity + hypoxia (main stressor under waterlogging conditions). We studied the effects of saline stress, alone or interacting with hypoxia, on growth, morphology and rooting process of six willows clones, assessing also whether rooting hormone (H, Indol Butyric Acid) contributes enhancing rooting under combined stress. Three hybrids of Salix matsudana × Salix alba (Sm×Sa), two of Salix babylonica × Salix alba (Sb×Sa) and a Salix nigra (Sn4) clone were evaluated in hydroponics. Ten treatments were generated combining salinity [moderate (MS): 5 dS/m, and high (HS): 10 dS/m]; hypoxia (with or without artificial aeration, HypO), and presence or absence of H. After 120 days, shoot and root biomass, root number and length, and hypertrophied lenticel number were evaluated. Contrary to what was expected, Sm×Sa and Sb×Sa hybrids showed no adverse additive effects of combined stress compared with saline stress; whereas in Sn4, S + HypO favored root biomass production increasing number and elongation of roots. Salinity was the main limiting factor for root production, being only MS conditions compatible with rooting, although limited. There was no common response in relation to H addition. In Sn4, H potentiated the effects of MS + HypO on root biomass, increasing number of roots. However, it had no positive effect on biomass production in the remaining hybrids, producing a higher root number but shorter in length. More effort is needed to understand the physiological mechanisms behind the response to combined stress in willows.

Cross-Talk Signaling in Rice During Combined Drought and Bacterial Blight Stress.

Due to climatic changes, rice crop is affected by moisture deficit stress and pathogens. Tissue water limitation besides reducing growth rates, also renders the crop susceptible to the infection by Xanthomonas oryzae pv. oryzae (Xoo) that causes bacterial leaf blight. Independently, both drought adaptation and Xoo resistance have been extensively studied. Though the cross-talk between drought and Xoo stress responses have been explored from individual stress studies, examining the combinatorial stress response is limited in rice. Recently published combined stress studies showed that under the combined stress, maintenance of carbon assimilation is hindered and such response is regulated by overlapping cellular mechanisms that are different from either of the individual stresses. Several receptors, MAP kinases, transcription factors, and ribosomal proteins, are predicted for playing a role in cellular homeostasis and protects cells from combined stress effects. Here we provide a critical analysis of these aspects using information from the recently published combined stress literature. This review is useful for researchers to comprehend combinatorial stress response of rice plants to drought and Xoo.

Genetic dissection of heat and drought stress QTLs in phenology-controlled synthetic-derived recombinant inbred lines in spring wheat

Abiotic stresses that affect wheat production—heat (H) and drought (D)—often occur concurrently. The genetic dissection of stress tolerance in a population with large range of phenology is difficult due to the confounding effects. We developed a recombinant inbred line (RIL) population of 276 entries with a narrow range of phenology, from a cross between a synthetic-derived parent (SYN-D: Croc 1/Aegilops squarrosa (224)//Opata) and an elite line (Weebill 1) to (a) understand the individual and combined effects of H and D stresses on yield and related traits, (b) identify the genetic basis of individual and combined stress tolerance, and (c) know the genetics of stress tolerance that can be explored from the line SYN-D. Phenotypic analysis indicated that the detrimental effect of combined stresses was greater than their individual effects. We constructed a genetic map—2771.5 cM—of the population with 569 SNPs (231 DArTseq and 338 Illumina bead chip 90 K array) and identified 71 QTLs, in which eight were common among stresses. We identified five QTL hotspots for yield and related traits under D, H, and H + D in chromosomes 2A (20.5 to 30.5 cM), 3D (92.5 to 108.5 cM), 6D (68.5 to 73.5 cM), 6D (125.5 to 135.5 cM), and 7B (40.5 to 61.5 cM). Among the 71 identified QTLs, SYN-D contributed 37 QTLs (52%) and Weebill 1 contributed 34 QTLs (48%). SYN-D also contributed the common thousand-grain weight QTL detected under H, D, and H + D, which can be used in molecular-assisted breeding.

Oxidative damage and antioxidant mechanism in tomatoes responding to drought and heat stress

Abiotic stresses especially combined stress such as concurrence of drought and heat will influence crop production more seriously in the near future. Reactive oxygen species (ROS) worked as signal transduction molecule to accelerate plant response at abiotic stress conditions, the accumulation of which caused oxidative damage. Understanding the underlying effect of combined stress on the ROS metabolism and antioxidant mechanism in plant is a prerequisite for crop improvement in a changing climate. We aimed to explore the distinct response of the ROS production and its scavenging system in tomato at single and combined stress and to elucidate the crosstalk of tolerance mechanism. Thereby, dynamic changes in ROS metabolism and antioxidant mechanism in tomatoes at control, drought, heat and drought + heat (combined stress) were investigated. Two tomato cultivars (Sufen 14: CV1, Jinlingmeiyu: CV2) were applied to compare the cultivar difference. 6 days of drought and combined stress led to a sharp increase in H2O2 (hydrogen peroxide) content and O2·− (superoxide radicals) production speed of both cultivars even though there were fluctuations from day 1 to day 5. Dramatic increase of SOD and APX activity and significant decrease of CAT activity occurred in both cultivars at all stresses on day 3. In contrast, combined stress significantly depressed the POD and CAT activity in both cultivars on day 6. The significant increase in MDA content was observed in CV1 at drought and combined stress and in CV2 at three stresses. Meanwhile, combined stress induced significant decrease in proline content only in CV1. The canopy area and stem diameter of both cultivars at the combined stress were smaller than single stress. We found that there was cultivar variation in heat tolerance but not in drought and combined stress tolerance. In conclusion, the stress tolerance of tomatoes at drought and heat is closely associated with its ability to respond to oxidative damage and regulation of ROS scavenging system with unique ROS response induced by the combined stress. This study not only increases our understanding of the complex ROS responses in plants to abiotic stress, but also provides knowledge to improve crop tolerance.

Hepato- and hemato-protective properties of α-ketoglutarate under the combined effect of water-immobilization and emotional stress

This article presents the results of the combined effect of water-immobilization and emotional stress on haematological and morphological parameters of blood and liver status of rats in conditions of correction of the disorders using by α-ketoglutarate. Experimental combined stress was induced by the interchangeable effect of dry immobilization and immersion in water for 3 days under constant illumination using an artificial lighting lamp of 1,000 lux., thus achieving a combined effect of stress. Physiological adaptation and administration of 5 mg/kg of body weight of α-ketoglutarate lasted 14 days after stress induction. Haematological parameters were determined using the Automated Veterinary Hematology Analyzer PCE 90 Vet (High Technology Inc., USA), while biochemical parameters of the liver state were determined by spectrophotometric and colourimetric methods. The obtained results showed an increase in hemolysis, which was determined by a decrease in the number of erythrocytes and haemoglobin concentration in the blood of rats under the effect of the stress factors studied. A negative consequence of strengthening of hemolysis is the development of hypoxia in the liver, which causes the slowing of metabolic processes in its cells. As a result, there is an accumulation of partially oxidized products: lactate and pyruvate, increased formation of TBA-active products, and oxidative modification of proteins. During the 14 days of physiological adaptation after stress, the main indicators of blood and liver status of the rats were partially restored. A stronger recovery of redox status and improvement of the physiological state of the liver and, hence, haematological parameters, were noted for rats that received α-ketoglutarate for 14 days after stress. The revealed general positive trend indicates the stimulation of adaptation processes and the overall functioning of the antioxidant system of the liver of rats in the use of α-ketoglutarate against the background of the combined effects of water-immobilization and emotional stress.

Silver stress differentially affects growth of phototrophic and heterotrophic chrysomonad flagellate populations

Silver ions are among the predominant anthropogenic introduced pollutants in aquatic systems. As silver has effects on species at all trophic levels the community composition in aquatic habitats can be changed as a result of silver stress. The response of planktonic protists to environmental stressors is particularly important as they act both as producers and consumers in complex planktonic communities. Chrysomonad flagellates are of major interest, since this group includes heterotrophic, mixotrophic and phototrophic taxa, and therefore allows analysis of silver stress in organisms with contrasting nutritional strategies independent of a potential taxonomic bias. In a series of lab experiments, we compared the response of different trophic chrysophyte strains to low (5 μg L−1), medium (10 μg L−1) and high (20 μg L−1) nominal Ag concentrations in combination with changes in temperature and light intensity (phototrophs), temperature and food concentration (heterotrophs), or a combination of the above settings (mixotrophs). All tested strains were negatively affected by silver in their growth rates. The phototrophic strains reacted strongly to silver stress, whereas light intensity and temperature had only minor effects on growth rates. For heterotrophic strains, high food concentration toned down the effect of silver, whereas temperatures outside the growth optimum had a combined stress effect. The mixotrophic strains reacted differently depending on whether their nutritional mode was dominated by heterotrophy or by phototrophy. The precise response pattern across all variables was uniquely different for every single species we tested. The present work contributes to a deeper understanding of the effects of environmental stressors on complex planktonic communities. It indicates that silver will negatively impact planktonic communities and may create shifts in their composition and functioning.

Interference between arsenic-induced toxicity and hypoxia.

Plants often face combinatorial stresses in their natural environment. Here, arsenic (As) toxicity was combined with hypoxia (Hpx) in the roots of Arabidopsis thaliana as it often occurs in nature. Arsenic inhibited growth of both roots and leaves, whereas root growth almost entirely ceased in Hpx. Growth efficiently resumed, and Hpx marker transcripts decreased upon reaeration. Compromised recovery from HpxAs treatment following reaeration indicated some persistent effects of combined stresses despite lower As accumulation. Root glutathione redox potential turned more oxidized in Hpx and most strongly in HpxAs. The more oxidizing root cell redox potential and the lowered glutathione amounts may be conducive to the growth arrest of plants exposed to HpxAs. The stresses elicited changes in elemental and transcriptomic composition. Thus, calcium, magnesium, and phosphorous amounts decreased in rosettes, but the strongest decline was seen for potassium. The reorganized potassium-related transcriptome supports the conclusion that disturbed potassium homeostasis contributes to the growth phenotype. In a converse manner, photosynthesis-related parameters were hardly affected, whereas accumulated carbohydrates under all stresses and anthocyanins under Hpx exclude carbohydrate limitation. The study demonstrates the existence of both synergistic since mutually aggravating effects and antagonistic effects of single and combined stresses.

Integrating transcriptomic techniques and k-means clustering in metabolomics to identify markers of abiotic and biotic stress in Medicago truncatula

IntroductionNitrogen-fixing legumes are invaluable crops, but are sensitive to physical and biological stresses. Whilst drought and infection from the soil-borne pathogen Fusarium oxysporum have been studied individually, their combined effects have not been widely investigated.ObjectivesWe aimed to determine the effect of combined stress using methods usually associated with transcriptomics to detect metabolic differences between treatment groups that could not be identified by more traditional means, such as principal component analysis and partial least squares discriminant analysis.MethodsLiquid chromatography-high resolution mass spectrometry data from the root and leaves of model legume Medicago truncatula were analysed using Gaussian Process 2-Sample Test, k-means cluster analysis and temporal clustering by affinity propagation.ResultsMetabolic differences were detected: we identified known stress markers, including changes in concentration for sucrose and citric acid, and showed that combined stress can exacerbate the effect of drought. Changes in roots were found to be smaller than those in leaves, but differences due to Fusarium infection were identified. The transfer of sucrose from leaves to roots can be seen in the time series using transcriptomic techniques with the metabolomics time series. Other metabolite concentrations that change as a result of treatment include phosphoric acid, malic acid and tetrahydroxychalcone.ConclusionsProbing metabolomic data with transcriptomic tools provides new insights and could help to identify resilient plant varieties, thereby increasing future crop yield and improving food security.

Caloric response of Fe49Rh51 subjected to uniaxial load and magnetic field

We have used differential scanning calorimetry and thermometry techniques under applied magnetic field and compressive uniaxial stress to determine isothermal entropy and adiabatic temperature changes that quantify the caloric effects associated with the magnetostructural transition of an ${\mathrm{Fe}}_{49}{\mathrm{Rh}}_{51}$ alloy. It is found that the transition temperature increases with increasing compressive stress while it decreases for increasing tensile stress. This behavior gives rise to a conventional elastocaloric effect for compressive stresses in contrast to the reported inverse elastocaloric effect for tensile stresses. The combined effect of stress and magnetic field does not lead to a significant increase of the maximum temperature and entropy changes associated with magnetocaloric and elastocaloric effects, but there is a modification of the temperature window where the sample exhibits giant caloric responses.