Low-temperature Treatment Research Articles

Integrated Transcriptomic and Metabolomics Analyses Reveal Molecular Responses to Cold Stress in Coconut (Cocos nucifera L.) Seedlings.

Coconut is an important tropical and subtropical fruit and oil crop severely affected by cold temperature, limiting its distribution and application. Thus, studying its low-temperature reaction mechanism is required to expand its cultivation range. We used growth morphology and physiological analyses to characterize the response of coconuts to 10, 20, and 30 d of low temperatures, combined with transcriptome and metabolome analysis. Low-temperature treatment significantly reduced the plant height and dry weight of coconut seedlings. The contents of soil and plant analyzer development (SPAD), soluble sugar (SS), soluble protein (SP), proline (Pro), and malondialdehyde (MDA) in leaves were significantly increased, along with the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the endogenous hormones abscisic acid (ABA), auxin (IAA), zeatin (ZR), and gibberellin (GA) contents. A large number of differentially expressed genes (DEGs) (9968) were detected under low-temperature conditions. Most DEGs were involved in mitogen-activated protein kinase (MAPK) signaling pathway-plant, plant hormone signal transduction, plant-pathogen interaction, biosynthesis of amino acids, amino sugar and nucleotide sugar metabolism, carbon metabolism, starch and sucrose metabolism, purine metabolism, and phenylpropanoid biosynthesis pathways. Transcription factors (TFs), including WRKY, AP2/ERF, HSF, bZIP, MYB, and bHLH families, were induced to significantly differentially express under cold stress. In addition, most genes associated with major cold-tolerance pathways, such as the ICE-CBF-COR, MAPK signaling, and endogenous hormones and their signaling pathways, were significantly up-regulated. Under low temperatures, a total of 205 differentially accumulated metabolites (DAMs) were enriched; 206 DAMs were in positive-ion mode and 97 in negative-ion mode, mainly including phenylpropanoids and polyketides, lipids and lipid-like molecules, benzenoids, organoheterocyclic compounds, organic oxygen compounds, organic acids and derivatives, nucleosides, nucleotides, and analogues. Comprehensive metabolome and transcriptome analysis revealed that the related genes and metabolites were mainly enriched in amino acid, flavonoid, carbohydrate, lipid, and nucleotide metabolism pathways under cold stress. Together, the results of this study provide important insights into the response of coconuts to cold stress, which will reveal the underlying molecular mechanisms and help in coconut screening and breeding.

The Effects of UV-C Irradiation and Low Temperature Treatment on Microbial Growth and Oxidative Damage in Fresh-Cut Bitter Gourd (Momordica charantia L.)

Fresh-cut fruits and vegetables are convenient and retain maximum nutrients. However, even minimal processing accelerates product deterioration and reduces food safety due to microbial infection. In this study, the effects of UV-C irradiation, low temperature treatment, and their combination on the microbial risk of fresh-cut bitter gourd were evaluated. Firstly, next-generation sequencing technology was utilized to identify microorganisms on the surface of fresh-cut bitter gourd after 12 h of exposure to room temperature, and a total of 34 bacterial species were identified. Subsequently, fresh-cut bitter gourd treated with UV-C or/and 4 °C and then kept at room temperature for 6 h was assessed for its viable bacterial count. The results showed that both 0.5 and 1.5 kJ·m−2 UV-C irradiation significantly inhibited microbial growth compared to 4 °C and the no treatment control. Meanwhile, no significant differences were observed between UV-C and the combined treatments. Lower doses of UV-C irradiation reduced hydrogen peroxide and malondialdehyde content, increased the proline level, and improved the activities of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, catalase, and critical enzymes involved in the phenylpropanoid pathway, such as phenylalanine ammonia-lyase and polyphenol oxidase. This suggests that UV-C irradiation alone can effectively reduce bacterial contamination in fresh-cut bitter gourd to an acceptable level.

Integrated transcriptome and metabolome analysis reveals the mechanism of carotenoid regulation in the yellowing-leaf mutant of pepper (Capsicum annuum L.) in response to different temperatures

Temperature is an important environmental factor affecting plant color, and different temperatures have distinct effects on plant leaf color changes. In order to explore the effects of different temperatures on plant color, we measured the physiological characteristics, transcriptome, and metabolome of the pepper leaf yellowing mutant yl1 and its wild type 6421 under different temperature conditions. Results showed that high temperature treatment compared with the normal temperature treatment significantly increased the contents of chlorophyll a, chlorophyll b, and carotenoids in yl1. At the same time, a total of 28 carotenoid pathway metabolites were detected under three temperature conditions. Among them, β-carotene, zeaxanthin, violaxanthin, neoxanthin, lutein, and antheraxanthin were higher in pepper leaves. The expression levels of ZEP, bHLH104, MYB1R1, and MYB1R1-like were significantly increased under high temperature compared with under normal temperature, while the expression level of crtZ-2 and VDE were significantly decreased. Co-expression network analysis showed that VDE was positively correlated with the bHLH71-like and negatively correlated with MYB1R1-like and bHLH104. These results led to significant differences in the amount of zeaxanthin and antheraxanthin accumulated at different temperatures, which may be the reason for the color change of pepper leaves. However, under the normal and low temperature treatment, it is the opposite, resulting in leaf yellowing. This study provides a reference for further research on the mechanism underlying the impact of temperature on carotenoid metabolism in pepper leaves.

Intralayered ostwald ripening impelled nanoarchitectonics of MXene nanorods on MXene nanosheets with boron carbon nitride for robust supercapacitor application

Utilizing 2D layered materials as one of the composite's members in the synthesis of active material for supercapacitors is acquiring imperative attention on account of the extraordinary outcomes due to their wholesome hale structural and electrochemical affinity. Here, by rousing from intralayer ostwald ripening impelled growth of in situ spawned 1D Nb2C rods on 2D Nb2C sheets, in short form (h)Nb2C are generated via hydrothermal low temperature treatment without, which overwhelms the electrochemical performance of pure 2D MXene sheets. Later the residue less direct pyrolysis method was adopted for the in-situ development of 2D BCN nanosheets over MXene, 1D-2D/2D MXene/BCN hybrid nanoarchitectonics. The process method enabled the interrelated structural growth of BCN particles on MXene and helps in empowering the pseudocapacitive activity of the enlarged portion of Nb sites by the removal of the terminal groups. Thus, the fabricated 1D-2D/2D Nb2C/BCN (NBCN) electrode showed a specific capacitance of 765 F g− 1 at 2 A g− 1 current density with a high specific energy of 35 Wh kg−1. Eventually, the solid-state supercapacitor device further withstands 100,000 cycles displaying high efficiency and ∼100% retention. Henceforth, the 1D-2D/2D heterostructures with magnificent electrochemical properties can act as a feasible energy storage system.

Influence of heat treatment conditions on crystallization and magnetic property of FeZrB amorphous alloys

Fe84Zr7B9 amorphous alloy prepared by a single-roller rapid quenching method was annealed under different heat treatment conditions (different annealing temperatures, heating rates, and vacuum pressure in the cooling process). The different heat treatment conditions result in different crystallization process. The different vacuum pressures used during cooling resulted indifferent distributions of Fe, Zr, and B in the crystallization phase, thus affording completely different crystalline phases. After low-temperature heat treatment, the saturation magnetization of the alloys treated with continuous vacuum is higher than that of the alloys treated without continuous vacuum, and the coercivity values of the alloys treated with and without continuous vacuum were similar. After high-temperature heat treatment, the saturation magnetization and the coercivity values of the alloys treated without continuous vacuum are higher than those of the alloy treated with continuous vacuum.

Preparation and properties of silica/hydroxyapatite whiskers porous ceramics scaffold

To investigate the preparation and properties of the novel silica (SiO 2)/hydroxyapatite (HAP) whiskers porous ceramics scaffold. The HAP whiskers were modified by the SiO 2 microspheres using the Stöber method. Three types of SiO 2/HAP whiskers were fabricated under different factors (for the No.1 samples, the content of tetraethoxysilane, stirring time, calcination temperature, and soaking time were 10 mL, 12 hours, 560℃, and 0.5 hours, respectively; and in the No.2 samples, those were 15 mL, 24 hours, 650℃, and 2 hours, respectively; while those in the No.3 samples were 20 mL, 48 hours, 750℃, and 4 hours, respectively). The phase and morphology of the self-made HAP whisker and 3 types of SiO 2/HAP whiskers were detected by the X-ray diffraction analysis and scanning electron microscopy. Taken the self-made HAP whisker and 3 types of SiO 2/HAP whiskers as raw materials, various porous ceramic materials were prepared using the mechanical foaming method combined with extrusion molding method, and the low-temperature heat treatment. The pore structure of porous ceramics was observed by scanning electron microscopy. Its porosity and pore size distribution were measured. And further the axial compressive strength was measured, and the biodegradability was detected by simulated body fluid. Cell counting kit 8 method was used to conduct cytotoxicity experiments on the extract of porous ceramics. The SiO 2 microspheres modified HAP whiskers and its porous ceramic materials were prepared successfully, respectively. In the SiO 2/HAP whiskers, the amorphous SiO 2 microspheres with a diameter of 200 nm, uniform distribution and good adhesion were attached to the surface of the whiskers, and the number of microspheres was controllable. The apparent porosity of the porous ceramic scaffold was about 78%, and its pore structure was composed of neatly arranged longitudinal through-holes and a large number of micro/nano through-holes. Compared with HAP whisker porous ceramic, the axial compressive strength of the SiO 2/HAP whisker porous ceramics could reach 1.0 MPa, which increased the strength by nearly 4 times. Among them, the axial compressive strength of the No.2 SiO 2/HAP whisker porous ceramic was the highest. The SiO 2 microspheres attached to the surface of the whiskers could provide sites for the deposition of apatite. With the content of SiO 2 microspheres increased, the deposition rate of apatite accelerated. The cytotoxicity level of the prepared porous ceramics ranged from 0 to 1, without cytotoxicity. SiO 2/HAP whisker porous ceramics have good biological activity, high porosity, three-dimensional complex pore structure, good axial compressive strength, and no cytotoxicity, which make it a promising scaffold material for bone tissue engineering.

Low-temperature aging treatment effect the properties of Ti-rich NiTi shape memory alloy

Low-temperature aging treatment effect the properties of Ti-rich NiTi shape memory alloy

Variability in thermal stress thresholds of corals across depths

Mesophotic habitats are potential refugia for corals in the context of climate change. The seawater temperature in a mesophotic habitat is generally lower than in a shallow habitat. However, the susceptibility and threshold temperatures of mesophotic corals are not well understood. We compared 11 mesophotic and shallow species to understand their thermal stress thresholds using physiological parameters. Coral fragments were exposed to two thermal stress treatments, with temperatures set at ~30°C and ~31°C, and a low-temperature treatment set at ~28°C as the “no stress” condition for 14 days. We found that the threshold temperature of coral species at mesophotic depths is slightly lower or equal to that of corals in shallow depths. The results suggest that species in the mesophotic coral ecosystems can survive low (<4 degree heating weeks) thermal stress. However, mass bleaching and high mortality can be expected when temperatures rise above 4 degree heating weeks.

Twice-split phosphorus application alleviates low-temperature impacts on wheat by improved spikelet development and setting

Extreme low-temperature incidents have become more frequent and severe as climate change intensifies. In Huang-Huai-Hai wheat growing area of China, the late spring coldness occurring at the jointing-booting stage (the anther interval stage) has resulted in significant yield losses of winter wheat. This study attempts to develop an economical, feasible, and efficient cultivation technique for improving the low-temperature (LT) resistance of wheat by exploring the effects of twice-split phosphorus application (TSPA) on wheat antioxidant characteristics and carbon and nitrogen metabolism physiology under LT treatment at the anther interval stage using Yannong 19 as the experimental material. The treatments consisted of traditional phosphorus application and TSPA, followed by a –4°C LT treatment and natural temperature (NT) control at the anther interval stage. Our analyses showed that, compared with the traditional application, the TSPA increased the net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr) of leaves and reduced the intercellular carbon dioxide concentration (Ci). The activity of carbon and nitrogen metabolism enzymes in the young wheat spikes was also increased by the TSPA, which promoted the accumulation of soluble sugar (SS), sucrose (SUC), soluble protein (SP), and proline (Pro) in young wheat spike and reduced the toxicity of malondialdehyde (MDA). Due to the improved organic nutrition for reproductive development, the young wheat spikes exhibited enhanced LT resistance, which reduced the sterile spikelet number (SSN) per spike by 11.8% and increased the spikelet setting rate (SSR) and final yield by 6.0 and 8.4%, respectively, compared to the traditional application. The positive effects of split phosphorus application became more pronounced when the LT treatment was prolonged.

Genome-Wide Identification and Expression Analysis of BrGeBP Genes Reveal Their Potential Roles in Cold and Drought Stress Tolerance in Brassica rapa.

The GLABROUS1 Enhancer Binding Protein (GeBP) gene family is pivotal in regulating plant growth, development, and stress responses. However, the role of GeBP in Brassica rapa remains unclear. This study identifies 20 BrGeBP genes distributed across 6 chromosomes, categorized into 4 subfamilies. Analysis of their promoter sequences reveals multiple stress-related elements, including those responding to drought, low temperature, methyl jasmonate (MeJA), and gibberellin (GA). Gene expression profiling demonstrates wide expression of BrGeBPs in callus, stem, silique, and flower tissues. Notably, BrGeBP5 expression significantly decreases under low-temperature treatment, while BrGeBP3 and BrGeBP14 show increased expression during drought stress, followed by a decrease. Protein interaction predictions suggest that BrGeBP14 homolog, At5g28040, can interact with DES1, a known stress-regulating protein. Additionally, microRNA172 targeting BrGeBP5 is upregulated under cold tolerance. These findings underscore the vital role of BrGeBPs in abiotic stress tolerance. Specifically, BrGeBP3, BrGeBP5, and BrGeBP14 show great potential for regulating abiotic stress. This study contributes to understanding the function of BrGeBPs and provides valuable insights for studying abiotic stress in B. rapa.

A novel low-temperature evaporation wastewater treatment apparatus based on hydrate adsorption.

Heavy metal pollution is an urgent challenge worldwide due to the acceleration of industrialization. While adsorption desalination is regarded as an innovative method for wastewater treatment, the current technologies have been impeded by high costs and intensive energy consumption. In this work, a novel low-temperature evaporation wastewater treatment apparatus based on hydrate adsorption was proposed. The water vapor from wastewater evaporation reacted with CO2 to form hydrate under the pressure of 3.3 MPa, constantly promoting wastewater evaporation due to the consumption of water vapor. The effect of feeding concentration on treatment effect was analyzed in terms of removal efficiency, water yield, and enrichment factor. Remarkably, a maximum removal efficiency of 97.4% can be achieved by treating an artificial solution with a Cu2+ concentration of 500 mg/L. Furthermore, compared with the control group that only depended on evaporation and condensation without forming hydrate, the maximum water yield of purified water in the experimental group increased to 310%. This innovative design concept for a low-temperature wastewater treatment apparatus based on hydrate adsorption presents a promising solution for the green and energy-efficient treatment of heavy metal wastewater.

The effect of moisture on nitrogen acquisition strategies of ephemeral desert plants in north-western China are regulated by temperature

AimsSymbiotic plants achieve partitioning of shared resources by chemical nutrient niche separation to escape competition. Understanding whether the nitrogen(N) nutrient acquisition strategies of ephemeral plants are influenced by temperature and moisture can facilitate the elucidation of plant coexistence strategies in desert ecosystems under environmental change. This study aimed to see whether changes in temperature and moisture affected the preferential uptake of different N chemotypes by ephemerals. MethodsIn this study, four dominant ephemerals in the Gurbantunggut Desert, Eremopyrum orientale, Erodium oxyrhinchum, Centaurea pulchella, and Lappula patula, were selected for controlled experiments in indoor pots. We conducted a short-term 15N follow-up experiment on potted treatments by setting two temperature gradients (low temperature(T1): 15 °C during the day and 5 °C at night; high temperature(T2): 25 °C during the day and 15 °C at night) and three moisture gradients (drought treatment(W1): soil moisture content of 2%; normal moisture treatment(W2): soil moisture content of 8%; wet treatment(W3): soil moisture content of 14%). Results Four ephemerals preferentially absorbed 15N-NH4 at low temperature treatment (T1), with a contribution ranging from 17.33% to 55.11%. The greatest uptake rate of 15N-NH4 was at the low temperature-normal moisture treatment (T1W2), and the fastest N uptake rate among the four plants could reach 13.84 μg·h–1, while at the high temperature-drought treatment (T2W1), the uptake was the smallest. However, plants showed the greatest preference for 15N-NO3 uptake at the high temperature treatment, with contributions ranging from 16.09% to 54.06%. The uptake rate of 15N-NO3 was greatest at the high temperature-wet treatment (T2W3), where the fastest N uptake rate among the four plants could reach 12.48 μg·h–1, and the smallest rate of 15N-NO3 at the low temperature-drought treatment (T1W1). The four ephemerals could also absorb organic N, 15N-Glycine, especially at the low temperatures. ConclusionsThe results showed that the four plants exhibited “Plasticity” in the uptake of the three N forms under different hydrothermal conditions. The effect of temperature and moisture interaction is more reflective of the N acquisition pattern of ephemeral plants in the desert. In low temperature environments, the uptake preference of ephemerals for N forms was mainly regulated by water, while in high temperature environments, the uptake of N forms by ephemerals was mainly regulated by temperature.

Low-temperature thermal treatment’s impact on hydroxyapatite nanofiber characteristics

Bone fractures caused by trauma or injury have been a worldwide public health concern. Therefore, bone tissue engineering has emerged as a viable option for addressing these issues by providing a variety of novel scaffold construction approaches. Bone is composed primarily with hydroxyapatite and carbonated apatite, which is 65% of the total mass. Therefore, many strategies have been conducted in fabricating bone scaffold with hydroxyapatite as the main biomaterials. The combination of electrospinning procedure and sol–gel method in generating hydroxyapatite nanofibers has some advantages due to the ability in replicating the content or structure of natural bone's extracellular matrix (ECM). The fibers were electrospun from a mixture of sol formed from polyvinylpyrrolidone (PVP)as the carrier and the calcium phosphate (CaP) precursors, followed by a thermal treatment that alter the fiber characteristics. Based on previous studies, the thermal treatment of pure hydroxyapatite phase has been suggested at least 600 °C However, no studies have done the thermal treatment at low temperature. Thus, this study investigates the impact of low-temperature thermal treatment on hydroxyapatite nanofibers. Observation on diameter and porosity of the fabricated fibers was conducted based on SEM images. The diameter of the fibers was decreased form 35.23 nm to 24.69 nm after the thermal treatment. Besides, the Ca/P molar ratio of the fabricated nanofibers was decreased from 15 to 8.16 after thermal treatment showing the potential of this formulation in achieving hydroxyapatite phase stoichiometry of 1.67. For future study, formulation at different PVP concentrations and different temperatures also need to be done in achieving better hydroxyapatite nanofibers properties.

Thickness of the Modified Polymer Layer Formed by Low-Temperature Plasma Treatment

Experimental data presented in the literature on the depth of processing of polymer films using low-temperature plasma are considered. Changes in the chemical composition and structure along the depth of the samples have been studied using the modern experimental techniques of X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and transmission electron microscopy; precision etching was carriedout with an Ar+2500 cluster beam; and the pit depth was measured by profilometry. It has been found that the thickness of the modified layer is ≤50 nm and depends relatively little on the polymer nature.

Detection of Transcription Factors Related to Axillary Bud Development after Exposure to Cold Conditions in Hexaploid Chrysanthemum morifolium Using Arabidopsis Information.

Chrysanthemum is one of the most commercially used ornamental flowering plants in the world. As chrysanthemum is self-incompatible, the propagation of identical varieties is carried out through cuttings rather than through seed. Axillary bud development can be controlled by changing the temperature; for instance, axillary bud development in some varieties is suppressed at high temperatures. In this study, we focused on the simultaneous axillary bud growth from multiple lines of chrysanthemum upon changing conditions from low to normal temperature. Transcriptome analysis was conducted on the Chrysanthemum morifolium cultivar 'Jinba' to identify the important genes for axillary bud development seen when moved from low-temperature treatment to normal cultivation temperature. We performed RNA-Seq analysis on plants after cold conditions in two-day time-course experiments. Under these settings, we constructed a transcriptome of 415,923 C. morifolium and extracted 7357 differentially expressed genes. Our understanding of Arabidopsis axillary meristem development and growth showed that at least 101 genes in our dataset were homologous to transcription factors involved in the biological process. In addition, six genes exhibited statistically significant variations in expression throughout conditions. We hypothesized that these genes were involved in the formation of axillary buds in C. morifolium after cold conditions.

Tuning the Pt-N coordination in Pt/MOFs nanosheets under N2 plasma for enhanced oxygen reduction reaction

Regulation of the local coordination of metal sites can tune the electronic structure of catalysts, thereby improving electrocatalytic activity and reaction selectivity. This study proposes a strategy for designing highly active catalysts by regulating Pt-N coordination through N2 plasma treatment. Zn-BDC (1,4-benzenedicarboxylic acid) nanosheets embedded with Pt nanoparticles (Pt/Zn-BDC) were successfully fabricated. Subsequently, radio frequency (RF) discharge N2 plasma was applied to tune the Pt sites of Pt/Zn-BDC at room temperature. The plasma-treated Pt/Zn-BDC showed enhanced catalytic activity for the oxygen reduction reaction (ORR) with a high half-wave potential (0.835 V), superior to those of pristine Pt/Zn-BDC and 20 wt% Pt/C. Notably, rechargeable Zn-air batteries based on plasma-treated catalysts were demonstrated to exhibit high efficiency and stability. The enhanced catalytic performance originated from the optimized coordination environment and electronic structure of the Pt sites under N2 plasma treatment. This study provides a facile, green method of regulating promising ORR electrocatalysts via low-temperature plasma treatment.

Superelasticity of Geometrically Graded NiTi Shape Memory Alloys

A stress plateau with a strain of 5–8% normally occurs during the stress-induced martensite transformation (SIM) of NiTi shape memory alloys. Within the stress plateau, the correlation between the stress and strain is lost, which limits their application in certain fields which require accurate control of inelastic deformation. In order to address this limitation, a series of step-like NiTi samples with graded cross-sectional area were designed and fabricated. Multiple stress plateaus were achieved by varying the sample width and adjusting the number of steps; for instance, two and three stress plateaus were obtained in the samples with two and three steps, respectively. Also, linear force–strain response was obtained by changing gradually the width of the samples. The functional stability of the geometrically graded samples was significantly improved by incomplete recrystallization annealing (600 °C) followed by low-temperature (250 °C) aging treatment. The incompletely recrystallized specimens contained many dislocations and grain and sub-grain boundaries, which promoted the uniform precipitation of Ni4Ti3 nanoparticles during aging treatment. The homogeneously and densely dispersed Ni4Ti3 nanoparticles were able to strengthen the matrix considerably and prevent plastic activities during stress-induced martensite transformation. As a result, the functional stability of the geometrically graded NiTi samples was much improved. After aging at 250 °C for 120 h, all the samples showed a small residual strain of <1.0% after 20 loading–unloading cycles.

The development of Au-titania photoanode composites toward semiflexible dye-sensitized solar cells

Considering the widespread use of windows in modern urban landscapes, converting these substrates into photovoltaic devices would remarkably impact modern energy generation. A flexible dye-sensitized solar cell (DSSC) architecture is preferred for such applications. A key component of the DSSC is the dye-sensitized photoanode. Herein, we examine different nanoparticle composites within the semiconductor anode formulation and their effect on device performance. Mesoporous titania particles (TiO2) modified with Au-nanoparticles (TiO2@AuNPs) were synthesized using precipitation strategies to assess the solvent effect on the particle size and the efficiency of the devices. The materials were then fully characterized through SEM, XRD, and DRS before and after thermal treatment. A paste prepared from the synthesized semiconductors was applied onto the substrate using the doctor blading technique. The use of high thermal treatment for glass substrates (HTT), low-temperature thermal treatment (LTT), and LTT combined with 2 h of UV curing (LTT_UV) was explored. In the case of ITO/PET (flexible substrate) only low temperature thermal treatment were used (LTT and LTT_UV). After characterization (XRD and DRS), the anodes were loaded using a metal-free dye. To complete the comparison, several groups of cells were characterized: considering solvent (EtOH and EtOH:H2O), thermal treatment (HTT, LTT, and LTT_UV), and semiconductor material (TiO2 and TiO2@AuNP). Rigid (glass anode-glass cathode) and semiflexible (flexible anode-glass cathode) DSSCs were obtained with efficiencies from 0.03% to 2.4%, with a substantial performance difference seen using different thermal treatments, and a mild to low effect on semiconductor composition and the used substrate.

Low temperature, mechanical wound, and exogenous salicylic acid (SA) can stimulate the SA signaling molecule as well as its downstream pathway and the formation of fruiting bodies in Flammulina filiformis.

Low temperature (LT) and mechanical wound (MW), as two common physics methods, have been empirically used in production to stimulate the primordia formation of Flammulina filiformis, which is typically produced using the industrial production mode. However, the detailed effect on the fruiting body formation and important endogenous hormones and signaling pathways in this process is poorly understood. In this study, LT, MW, their combination, i.e., MW + LT, and low concentration of SA (0.1 mM SA) treatments were applied to the physiologically mature mycelia of F. filiformis. The results showed that the primordia under the four treatments began to appear on the 5th-6th days compared with the 12th day in the control (no treatment). The MW + LT treatment produced the largest number of primordia (1,859 per bottle), followed by MW (757), SA (141), and LT (22), compared with 47 per bottle in the control. The HPLC results showed that the average contents of endogenous SA were significantly increased by 1.3 to 2.6 times under four treatments. A total of 11 SA signaling genes were identified in the F. filiformis genome, including 4 NPR genes (FfNpr1-4), 5 TGA genes (FfTga1-5), and 2 PR genes (FfPr1-2). FfNpr3 with complete conserved domains (ANK and BTB/POZ) showed significantly upregulated expression under all four above treatments, while FfNpr1/2/4 with one domain showed significantly upregulated response expression under the partial treatment of all four treatments. FfTga1-5 and FfPr1-2 showed 1.6-fold to 8.5-fold significant upregulation with varying degrees in response to four treatments. The results suggested that there was a correlation between "low temperature/mechanical wound-SA signal-fruiting body formation", and it will help researchers to understand the role of SA hormone and SA signaling pathway genes in the formation of fruiting bodies in fungi.

Cloning, Characterization, and Functional Analysis of EuTIL1, a Gene-Encoding Temperature-Induced Lipocalin in Eucommia ulmoides Oliv

Eucommia ulmoides Oliver is a unique tertiary relict tree species in China belonging to the Eucommia family and genus. It is a traditional and precious Chinese medicinal herb with anti-tumor, antibacterial, antioxidant, anti-inflammatory, and bidirectional blood pressure regulation effects. Eucommia ulmoides mainly grows in temperate regions of China, but due to its sensitivity to low-temperatures, it is difficult to introduce into new regions. To study the role of Eucommia ulmoides lipocalin in plants. This investigation was conducted utilizing gene cloning, bioinformatics analysis, quantitative real-time polymerase chain reaction (qRT-PCR), subcellular localization, and stable genetic transformation to transfer EuTIL1 into Nicotiana tabacum Xanthi. The wild-type transgenic vector and EuTIL1 tobacco were cold-treated, and the corresponding protective enzyme activity and cold-induced gene expression levels were measured to analyze the functions of the genes. In this study, the full-length of the temperature-induced lipocalin gene (EuTIL1) cDNA was cloned from the leaves of Eucommia ulmoides using the rapid amplification of cDNA ends (RACE) method. The sequence analysis showed that the full-length cDNA of EuTIL1 was 917 bp and encodes a protein of 188 aa residues, which is a member of the Lipocalin-2 family. Subcellular localization analysis revealed that EuTIL1 was found in the plasma membrane. The transgenic tobacco lines expressing EuTIL1 under the control of the CaMV 35S promoter had increased tolerance to cold compared to wild-type (WT) plants. The average water loss rate of EuTIL1 transgenic plants was 12.4%, the average conductivity at 24 h was 55.11%, and the malondialdehyde content at 24 h was significantly lower than that of wild-type plants. The maximum soluble sugar (SS) content, superoxide dismutase (SOD) activity, peroxidase (POD) activity, and catalase activity of EuTIL1 plants after low-temperature treatment were 22.03 mg/g, 726.87 U/g, 1283.94 U/g, and 356.84 U/g, respectively, which are significantly higher than those of the wild-type. Meanwhile, in the EuTIL1 transgenic tobacco plants, the expression of the NtDREB1, NtDREB2, NtDREB4, and NtCOR15a elevated under the low-temperature treatment condition. In conclusion, our study demonstrates that EuTIL1 is a gene involved in the cold-stress response and has the potential to enhance cold tolerance in plants, providing a potential molecular basis for the study of Eucommia ulmoides introduction and serving as a candidate gene for evaluating cold-tolerant plants.