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

YTH domain-containing genes are important readers of N6-methyladenosine (m6A) modifications with ability to directly affect the fates of distinct RNAs in organisms. Despite their importance, little is known about YTH domain-containing genes in teleosts until now. In the present study, a total of 10 YTHdomain-containing genes have been systematically identified and functionally characterized in rainbow trout (Oncorhynchus mykiss). According to the phylogenetic tree, gene structure and syntenic analysis, these YTHdomain-containing genes could be classified into three evolutionary subclades, including YTHDF, YTHDC1 and YTHDC2. Of them, the copy number of OmDF1, OmDF2, OmDF3, and OmDC1 were duplicated or even triplicated in rainbow trout due to the salmonid-specific whole-genome duplication event. The three-dimensional protein structure analysis revealed that there were similar structures and the same amino acid residues that were associated with cage formation between humans and rainbow trout, implying their similar manners in binding to m6A modification. Additionally, the results of qPCR experiment indicated that the expression patterns of a few YTH domain-containing genes, especially OmDF1b, OmDF3a and OmDF3b, were significantly different in liver tissue of rainbow trout under four different temperatures (7 °C, 11 °C, 15 °C, and 19 °C). The expression levels of OmDF1a, OmDF1b and OmDC1a were obviously repressed in spleen tissue of rainbow trout at 24 h after Yersinia ruckeri infection, while increased expression was detected in OmDF3b. This study provides a systemic overview of YTH domain-containing genes in rainbow trout and reveals their biological roles in responses to temperature stress and bacterial infection.

Chimonanthus praecox is an important ornamental plant and cut flower material in China. It blooms in the freezing winter and its flower emits charming fragrance. However, in different region the flowering time is variable. In order to understand the flowering mechanism of Ch. praecox in the winter, we studied the flower bud differentiation in Spring City-Kunming using paraffin sectioning method in the present study. Meanwhile we compared the differentiation process difference from different regions. It was found that the temperature is the key factor for its flower bud differentiation and blossom of Ch. praecox. In the process of bud differentiation, the temperature 20 °C was the optimum for inducing changes from vegetative axillary buds to reproductive buds and subsequent morphological differentiation in Ch. praecox. Furthermore in the first three differentiation periods—tepal primordial stage, staminal primordial stage and pistil primordial stage, Kunming took the shortest time to finish the process due to very rapid temperature rise to 20 °C, whereas, in Zhengzhou the time for these differentiations was the longest, which may be caused by the slow temperature rise. After May, the high temperature stress forced the flower buds into the first long dormant period in all regions except Kunming. In Kunming, the average temperature was only 20–25 °C, so the flower bud continued to differentiate. In all regions, Kunming is the first to complete whole flower bud differentiation even on the early August, and started the second dormancy very early but very long. In the other regions, the plants went through a shorter dormancy and the low temperature broke the dormancy rapidly. Contrarily the plants of Kunming spent a longer period for the low temperature. Thus, the low temperature less than 10 °C is a key factor to breaking the second dormancy. Surely the regular effects of temperature on flower bud differentiation and blossom is very helpful for florescence regulation of Ch. praecox.

The problem of temperature variation in mass concrete construction is a crucial problem in civil engineering. The problems of the temperature field, damaged areas, and the cracking of the structure during the construction process of concrete pouring are analyzed in this paper. An elastic and damaged constitutive model for concrete and a fully coupled analysis method for analyzing the temperature-stress field was proposed to simulate and predict the construction process of a concrete structure in a metro station. The influence of different concrete compositions and material properties was not taken into account in this study. The results show that the temperature-stress complete coupling analysis method can be applied to the calculation and analysis of cracking in a concrete structure that is caused by internal temperature variations during the pouring process of complex concrete structures. An efficient method and research approach is proposed by this study to analyze the damage and cracking issues caused by temperature changes during the pouring process of concrete structures in metro stations. The area and extent of the damage and cracking during the construction can be predicted and evaluated, and a reference for metro station construction and operation is proposed.

We report the dual gate (DG) amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistor (TFT) with a top-gate (TG) drain offset (LTG(Off)) structure under dual-gate driving. The TFT shows an on/off current ratio of ~107, subthreshold swing of 0.23 V/dec, and field-effect mobility (μFE) of 14.6 cm2/Vs when LTG(Off) is 5 μm, which is 30% reduction compared to the conventional DG TFT with no drain offset (μFE=20.9 cm2/Vs). The Technology computer-aided design simulation indicates the electron concentration of ~1016 /cm3 at the offset region near top gate insulator/a-IGZO interface when LTG(Off) is 5 μm. The fabricated TFT exhibits stable performance under positive bias temperature stress with a threshold voltage shift of +0.1 V.

Low temperature has negative effects on apple photosynthesis by inhibiting the accumulations of photosynthates and nitrogen. The interactive effects of low temperature and nitrogen application on photosynthetic parameters and the absorption and distribution of carbon and nitrogen in different organs were assessed to investigate if nitrogen application can relieve the low-temperature stress on gas exchange and the accumulations of carbon and nitrogen inside the apple plants. No matter under normal or low-temperature conditions, nitrogen application both improved the photosynthetic parameters including net photosynthetic rate, intercellular CO2 concentration, and quantum yield of regulated energy dissipation of PSII as well as the absorption of carbon and nitrogen in roots, stems, and leaves. Thus, we conclude that nitrogen application can relieve the effects of low-temperature stress on photosynthesis and is of benefit for the accumulations of carbon and nitrogen in multiple organs of apple seedlings.

Aiming at the synergistic rock-breaking mechanism of supercritical carbon dioxide (SC-CO2) jet pressure and temperature difference, a heat-fluid-solid calculation model of rock-breaking stress was established and verified to be effective, and the variations of jet flow field and rock stress with jet standoff distance of SC-CO2, water and nitrogen were studied. With the increase of jet standoff distance, the jet pressure of SC-CO2 decreases and the jet temperature difference increases. The SC-CO2 jet is higher in pressure than the nitrogen jet and differs little from the water jet. Temperature difference of SC-CO2 jet is 5 times that of water jet and more than 2.5 times that of nitrogen jet when the jet standoff distance is larger than 10. The temperature stress is the main reason why SC-CO2 jet is superior to water and nitrogen jets in rock-breaking. The rock under the SC-CO2 jet has greater rock stress, effective rock-breaking jet standoff distance and rock-breaking area. The jet pressure plays a major role in rock-breaking when the jet standoff distance is small, while the jet temperature difference plays a major role in rock-breaking when the jet standoff distance is large. The SC-CO2 jet is an efficient volume rock-breaking method, which results in tensile and shear failure on the rock surface under short time jet and large area tensile failure inside the rock simultaneously under long time jet.

Cotton is a tropical/subtropical crop and is innately susceptible to cold. Using an approach that integrates morphological, biochemical, and transcriptome analyses, the study aimed to understand the molecular underpinnings of phenotypic adjustments in cotton seedlings under cold stress. Exposure of six cotton accessions to 15°C during the seedling stage significantly reduced chlorophyll content, stomatal conductance, plant height, and biomass, but increased malondialdehyde and proline production. Comparative transcriptome profiling of the cold‐sensitive accession SA 3781 grown under low and normal temperatures showed the upregulation of genes related to the production of reactive oxygen species (ROS) under cold stress. Despite a similar upregulation of genes encoding metabolites that can scavenge ROS and provide osmoprotection for the cell, the stressed plants still exhibited oxidative stress in terms of lipid peroxidation. This may be due in part to the upregulation of abscisic acid synthesis genes and downregulation of chlorophyll synthesis genes effecting lower stomatal conductance and chlorophyll contents, respectively. Additionally, stomatal closure which is required to avoid the cooling effect and dehydration under cold conditions may have contributed in reducing the net photosynthetic rates in plants exposed to low temperature. These findings provide an insight into the expression of key genes regulating the phenotypic changes observed in cotton in response to cold stress.

This research was carried out to investigate the possibilities of removing the heat stress that may occur in Anatolian water buffaloes with a fogging system and to determine the cooling efficiency of the system. In this context, two 24-headed groups were formed among the water buffaloes that were considered to have the same genetic similarities, were born in the same period and have the same lactation number. One group was housed under controlled shelter conditions (Shelter-I), where the ambient temperature can be controlled, and the other group was housed in existing farmer-raising conditions (Shelter-II). The same feed rations were applied to both buffalo groups. The cooling efficiency of the fogging system established in Shelter-I was between 45.6% and 85.7% positive. Temperature-Humidity Index values changed between 19.9 and 23.1 in Shelter-I and 19.5 and 26.4 in Shelter-II according to the maximum average data. According to these values, the level of stress in Shelter-II has reached very serious levels and affected the milk yield of buffaloes negatively. The corrected 305-day lactation milk yields were calculated as 1965.4 kg in Shelter-I and 1757.1 kg in Shelter-II. The differences between all data obtained for Shelter-I and Shelter-II were found statistically significant.

A transfer–purge chamber (TPC) is a double-steel-plate, heavy-concrete, curved-surface composite structure composed of steel plates, heavy concrete, and shear connectors. It is an important facility in the external refueling system of a nuclear power plant (NPP), providing a safe and reliable biological shielding space for reactor refueling operations. Temperature load is one of the most important factors that must be considered in the design of NPP structures. The temperature loads experienced by the TPC during its life cycle include those encountered in both normal and abnormal operation, which are distinct. In this study, we investigated the steady state and transient-state temperature fields and stresses of a TPC structure under normal operation and after 48 h of abnormal operation, respectively, which were calculated using Abaqus finite element software and the directly coupled method. During normal operation, the temperature field of the structure shows relatively uniform changes, and the temperature gradient of the internal concrete in the direction of its thickness has a constant value of 0.245 °C/cm. At the junction between the transfer and purge sub-chambers of the TPC, under the influence of wall curvature and deformation constraints, the maximum tensile strain of heavy concrete is 8.84 × 10−3, the maximum compressive strain is 2.04 × 10−3, the peak stress of the steel plate is 98.305 MPa, and the peak stress of the stud is 306.725 MPa. After 48 h of abnormal operation, the temperatures of the inner surface of the heavy concrete of the wall, the inner steel plate of the wall, the outer surface of the heavy concrete of the wall, and the inner steel plate of the wall increased by 8.12, 8.11, 0.31, and 0.30 °C, respectively. The tensile strain of the heavy concrete of the wall increased significantly by 52.64%, and the compressive strain of the concrete increased by 67.33%, whereas the stresses of the studs and steel plates increased by only 1.57% and 6.79%, respectively. These results show that the change in the temperature field greatly influences the stress and strain on the TPC structure. As measures for mitigating the development of this unfavorable situation of temperature stress concentration, the temperature operating range should be rationally controlled or the junction structure between the transfer and purge sub-chambers of the TPC optimized accordingly. The results of our study can provide basic data for a dynamic analysis of the TPC under conditions of combined earthquake and temperature loads.

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

After light, temperature is the most relevant environmental parameter in outdoors cultivation of microalgae. Suboptimal and supraoptimal temperatures negatively impact growth and photosynthetic performance with a subsequent effect on lipid accumulation. It is generally recognised that lower temperatures trigger an increase in fatty acid desaturation while higher temperatures trigger the opposite reaction. The effect of temperature on lipid classes has been less studied in microalgae and in certain cases, the effect of light cannot be completely excluded. In this research, the effect of temperature on growth, photosynthesis, and lipid class accumulation in Nannochloropsis oceanica was studied at a fixed light gradient with a constant incident light intensity (670 μmol m-2 s-1). A turbidostat approach was used to achieve temperature acclimated cultures of Nannochloropsis oceanica. Optimal growth was found at 25-29°C, while growth was completely arrested at temperatures higher than 31°C and lower than 9°C. Acclimation to low temperatures triggered a decrease in absorption cross section and photosynthesis rates with a tipping point at 17°C. Reduced light absorption was correlated with a decrease in content of the plastid lipids monogalactosyldiacylglycerol and sulfoquinovosyldiacylglycerol. The increase of diacylglyceryltrimethylhomo-serine content at lower temperatures indicated a relevant role of this lipid class in temperature tolerance. Triacylglycerol content increased at 17°C and decreased at 9°C emphasising a metabolic switch in stress response. Total and polar eicosapentaenoic acid content remained constant at 3.5 and 2.4% w/w, despite the fluctuating lipid contents. Results show an extensive mobilisation of eicosapentaenoic acid between polar lipids classes at 9°C to ensure cell survival under critical conditions.

Climate change is a global challenge that has changed the physiological and biochemical parameters of plants. Plants are sessile organisms and their survival depends on the effective activation of metabolic mechanisms of resistance to such stress. In the scope of this work, we investigated the influence of low (0⁰C) and high (80⁰C) water temperature on the metabolism of young broccoli plants (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.) with the aim of adefining the parameters that indicate susceptibility or resistance of broccoli to stress caused by low and high water temperature, and b) evaluating the changes in selected parameters of broccoli metabolism due to these two types of stress. For the determination of bioactive compounds, we used high performance liquid chromatography and spectrophotometric methods. For all pigments, except chlorophyll a, a statistically significant difference was observed between the group treated with high temperature water and the remaining two groups (control and group treated with cold water). The highest proportion of chlorophyll b was found in the group treated with hot water. Regarding the proportions of total porphyrins and lycopene, a difference was also observed between the group treated with hot water and the other two groups. The proportion of carotenoids, on the other hand, was the lowest in the group treated with hot water. The proportion of total proanthocyanidins in young broccoli plants was the highest in the group treated with hot water, while the proportion of total hydroxycinnamic acids and flavonols was significantly lower in the group treated with hot water than in the other two groups. The proportion of the remaining four groups of compounds (total phenols, flavonoids, tannins and phenolic acids) in broccoli subjected to stress caused by high and low temperature water did not statistically differ from the control group.

Antipatharians, also called black corals, are colonial benthic cnidarians with a global distribution across oceans and depths. They can reach high population densities, providing a complex habitat and generating high biodiversity hotspots. The mesophotic black coral Antipathella wollastoni has been described in the Canary Archipelago establishing extensive forests. Studies on antipatharian sensitivity to rising ocean temperatures are scarce and due to the projections related to ocean warming in the Canary Islands, heat stress experiments in this location seem especially important. This experimental study presents for the first time an evaluation of the thermal sensitivity of A. wollastoni specimens through 15 days of exposure (from 19 to 26.5 °C) in a laboratory environment and further stress responses to temperature increase. Oxygen consumption measurements allowed to identify the physiological optimal temperature (ca. 26.1 °C; ca. 1.4°C above mean ambient condition) and a wide thermal performance (ca. 7.6 ºC). Other stress responses, such as tissue necrosis and polyp bail-out, were also observed with increasing temperature. This investigation also provided for the first-time insights into the production of propagules by A. wollastoni, indicating that temperature might influence the occurrence of polyp bail-out. It is suggested that due to large short-term environmental temperature fluctuations and mechanisms such as phenotypic plasticity or genotype selection, this species might adopt a thermal generalist strategy. Even though this study provides insights into the thermal performances of A. wollastoni, this knowledge cannot be directly extrapolated to what will happen in upcoming decades under climate change scenarios. In this way, for future investigations, further heat stress experiments on black corals are advisable, as well as research on polyp bail-out and settlement, in order to better understand the limitations and coping mechanisms of Antipatharia with ocean warming. Os Antipatários, chamados de corais negros, são cnidários bentónicos com distribuição global pelos oceanos e existindo a diferentes profundidades. Podem atingir densidades populacionais elevadas, fornecendo habitat e promovendo a existência de biodiversidade. O coral negro mesofótico Antipathella wollastoni foi descrito no Arquipélago das Canárias, sendo conhecido por estabelecer extensas florestas. Os estudos sobre a sensibilidade dos antipatários ao aquecimento dos oceanos são ainda escassos e devido às projeções relacionadas com este aquecimento nas Ilhas Canárias, as experiências de stress térmico nesta região são importantes. Este estudo providencia pela primeira vez uma avaliação à sensibilidade térmica de A. wollastoni após 15 dias de exposição (de 19 a 26.5 °C) a diferentes temperaturas da água em laboratório. As medições do consumo de oxigénio realizadas permitiram identificar uma temperatura fisiológica ótima (ca. 26.1 °C; ca. 1.4 °C acima da condição ambiente média), um desempenho térmico amplo (ca. 7.6 °C), e um conjunto de respostas ao stress, como a necrose de tecidos e a libertação de propágulos com o aumento da temperatura. Esta investigação também possibilitou pela primeira vez a descoberta da produção destes propágulos para A. wollastoni, indicando que a temperatura pode influenciar a libertação dos mesmos. Sugere-se que devido às flutuações de temperatura ambiental que existam a curto prazo e aos mecanismos de plasticidade fenotípica ou seleção genotípica que esta espécie apresenta, esta possa adotar uma estratégia generalista térmica. Ainda que este estudo forneça informações acerca da janela termal de A. wollastoni, este conhecimento não pode ser diretamente extrapolado para os efeitos esperados para as próximas décadas num cenário de alterações climáticas. Desta forma, é aconselhável realizar mais experiências no âmbito do stress térmico dos corais negros e novos trabalhos abordando a produção e estabelecimento de propágulos, de modo a compreender as limitações e mecanismos de sobrevivência dos Antipatários de acordo com o aquecimento dos oceanos. Mestrado em Biologia Marinha Aplicada

Urea can solve the problem of concrete cracking due to temperature stress. However, its effect is affected by temperature. The influencing mechanism of temperature on urea-doped cement pastes is still unclear. This paper explores the effect of different temperatures on the hydration kinetics of urea-doped cement pastes. The isothermal calorimeter (TAM Air) was used to test hydration at three constant temperatures (20 °C, 40 °C, and 60 °C). The effects of the urea admixture and temperature on the hydration process and hydration kinetics parameters were investigated. The hydration mechanism was analyzed, and the changes in macroscopic mechanical compressive strength and porosity were tested. The results show that, as the urea content (UC) increases, the rate of hydration gradually decreases, and the increase in temperature promotes the inhibitory effect of urea. At 60 °C, UC of 8% can be reduced by 23.5% compared with the pure cement (PC) group’s hydration rate. As the temperature increases from 20 °C to 60 °C, the Krstulovic–Dabic model changes from the NG-I-D process to the NG-D process. The effect of urea on the compressive strength of the cement is mainly shown in the early stage, and its effect on later strength is not obvious. In addition, urea will increase its early porosity. The porosity will gradually decrease in the later stage. The results of the study clarify the effect of temperature on urea-doped cement pastes. The optimal content of urea in cement is about 8%, which will provide theoretical guidance for solving the cracking problem of large-volume concrete due to temperature stress.

High temperature stress severely interrupts the physiological and biochemical functions in plants which hinders the growth, development and productivity of cowpea. The present study evaluates the potential roles of Naphthalene Acetic Acid and Brassinolide for mitigating the adverse effects of high temperature in cowpea. The study was carried out during the year 2021 in cowpea variety CO 7 using Temperature Gradient Tunnel (TGT) located at Agro Climate Research Centre, Tamil Nadu Agricultural University (TNAU), Coimbatore. The experimental design followed was Factorial Completely Randomized Design (FCRD). Different treatments were imposed on plants exposed to ambient and ambient +2oC temperature. The effect of treatments on leaf area index, photosynthetic rate, chlorophyll index and seed yield were studied. The application of brassinolide @ 0.2ppm showed a positive effect on stressed plants and produced the highest seed yield of 8.78 g plant-1.

The experiment was carried out to screen mustard genotypes under individual and combined salinity and high-temperature stress at seedling stage. Seeds after being sown in soil-filled trays were subjected to two levels of salinity stress i.e. 4.0 dSm-1 and 6.0 dSm-1, and high-temperature (40℃), and their performances were also compared with control (1.2 dSm-1). Contrasting sets of genotypes were selected on the basis of seedling growth parameters such as germination percentage, seedling length, dry weight of seedlings, vigour index-I and vigour index-II, recorded in 15-day-old seedlings. With consideration to the genotypic variations observed under all the treatments, genotypes CS2009-347 and CS-52 were identified as tolerant, and genotypes CS2009-256 and CS2009-145 were identified as susceptible under salinity and high-temperature stress conditions. The results also revealed that the impact of salinity and high-temperature in combination on mustard at seedling stage was more detrimental than that of their effects under individual conditions. These findings of genotypic variations in terms of tolerance in seedling stage of Indian mustard might be helpful in selection of genotypes with improved tolerance to salinity and high-temperature.

High temperature (HT) stress has become one of the most detrimental stresses in crop production among constantly changing environmental factors. Exploiting approaches to enhance crop thermotolerance would have great significance in assuaging adverse effects of HT stress on crop growth and development. As jasmonates (JAs) and brassinosteroids (BRs) are novel phytohormones and play important roles in responses to biotic and abiotic stresses and in a wide range of plant developmental processes, this paper reviewed the roles and mechanisms of JAs and BRs in mitigating HT stress, with focus on rice (Oryza sativa L.) subjected to HT stress during anthesis. It is demonstrated that JAs alleviate spikelet-opening impairment and BRs ameliorate pistil fertilization ability under HT stress during anthesis of rice, although there are controversial observations. Activating the defense system, enhancing osmotic regulation, protecting photosynthesis, and interacting with other phytohormones, especially with ethylene and abscisic acid, are main physiological mechanisms by which JAs or BRs attenuate HT stress to plants. Elevating levels of JAs or BRs in plants could be considered as an important approach to enhance crop thermotolerance through breeding new varieties. Using JAs or BRs as chemical regulators and adopting proper water and nitrogen management practices could reduce the harm of HT stress to rice. Further research is needed to elucidate the roles of JAs and BRs in different plant tissues in responses to HT stress under different genetic backgrounds and environments, reveal the molecular mechanism underlying JAs and BRs mediating HT stress, understand the cross-talk between phytohormones in modulating HT stress, and establish integrated crop management to minimize the hazard of HT stress in rice production.

Shrub is one of the unique woody tree species in China. It has a long history of cultivation, a wide range of adaptability, high economic value and strong ecological function. It plays a very important role in the southern economic forest industry. Low temperature has a great impact on the afforestation and growth of the dormant shrub seeds in the northern edge of China, which is the bottleneck of the promotion of shrub plants in the northern edge of China. In this study, 10 kinds of dormant shrub seeds in China were selected as the research objects. The dormant shrub seeds were treated with different temperature and different time of low temperature stress. The physiological and biochemical indexes under different treatments were measured to comprehensively evaluate the cold tolerance of 10 kinds of dormant shrub seeds.

Rhus chinensis Mill. (RCM) is the host plant of Galla chinensis, which is valued in traditional medicine. Environmental temperature directly determines the probability of gallnut formation and RCM growth. At present, there is no experiment to systematically analyse the stability of internal reference gene (RG) expression in RCM. In this experiment, leaves that did not form gallnuts were used as the control group, while leaves that formed gallnuts were used as the experimental group. First, we conducted transcriptome experiments on RCM leaves to obtain 45 103 differential genes and functional enrichment annotations between the two groups. On this basis, this experiment established a transcriptional gene change model of leaves in the process of gallnut formation after being bitten by aphids, and RCM reference candidate genes were screened from RNA sequencing (RNA‐seq) data. This study is based on RCM transcriptome data and evaluates the stability of 11 potential reference genes under cold stress (4 °C) and heat stress (34 °C), using three statistical algorithms (geNorm, NormFinder, and BestKeeper). The results show that GAPDH1 + PP2A2/UBQ are stable reference genes under heat stress, while GAPDH1 + ACT are the most stable under cold stress. This study is the first to screen candidate reference genes in RCM and could help guide future molecular studies in this genus., Appropriate and stable reference genes are important for normalization of gene expression. This study is based on Rhus chinensis Mill. transcriptome data and evaluates the stability of 11 potential reference genes under cold stress (4 °C) and heat stress (34 °C), using three statistical algorithms (geNorm, NormFinder, and BestKeeper). This study is the first to screen candidate reference genes in Rhus chinensis Mill. and could help guide future molecular studies in this genus.

Abiotic stresses are serious problems that hinder crop production. Seed germination and seedling development are stages which are sensitive to abiotic stress. Seed priming improves the performance of seeds/seedlings and provides faster and synchronized emergence under stress conditions. The present study aimed to investigate the effect of priming with biostimulants, vermicompost (5%), karrikinolide (10-7 M) and seaweed (5%) using the solid matrix method (5 days, dark, 15 °C, 2:1:3, seed:vermiculite:organic solution, w:w:w) on germination and seedling quality of carrot seeds under abiotic stress conditions. Biostimulants were used alone and in double and triple combinations. Drought stress was simulated by PEG-6000 (-0.3 MPa), salinity by using NaCl at 100mM, and high temperature by 30 °C. Dry control and distilled water treated were used as controls. Priming treatment with biostimulants improved performance of seeds and seedlings, though not always significantly (p=0.05). Seaweed alone and its combination with karrikinolide showed the best performance for all the parameters. The germination percentage for dry control of carrot seeds were 37, 63 and 72% in salt, drought and high temperature stresses while distilled water treated seeds had values of 74, 79 and 77%, respectively. Seeds treated with seaweed+ karrikinolide and seaweed alone had 80 and 89% germination. The same treatments stimulated seedling emergence from 57% to 84-88%, 25 to 69-76%, 71 to 85-87% under drought, salt and high temperature stress, respectively. Seedling criteria, seedling height, fresh weight, dry weight and root fresh weight were also higher with these treatments in all stress conditions. Catalase activity of treated seeds was higher for seaweed (0.400 EUg-1seed) and seaweed karrikinolide (0.411 EUg-1seed) treated seeds than for both controls (non-primed: 0.299, distilled water: 0.239 EUg-1seed). Biostimulants have potential as seed priming agents to enhance seed quality in carrots.

The papers presented in this special issue are focused on the development of mutant lines and new crop varieties of rice and common bean with improved adaptation to climate change. Also included are the development or adaptation of screening techniques that enable efficient selection of desired phenotypes in plant breeding programmes. The breeding methods used are based on mutation induction and mutation detection, where mutation induction is via physical mutagenesis using gamma and X-ray irradiation. Selection for improved mutant lines is achieved through screening for plant performance in the laboratory, green house and field under hight temperature and/or drought stress. The papers presented are the result of a 5-year coordinated research project (CRP) on Climate Proofing Crops: Genetic Improvement for Adaptation to High Temperatures in Drought Prone Areas and Beyond, funded by the IAEA. The CRP, initiated in 2011, focused on tolerance to increased temperatures in rice and common bean. All participating countries generated new mutant populations in rice and bean and identified heat-tolerant lines with better yields than local standard varieties

Global warming has endangered crop production by reducing water availability and increasing temperature. Kaolin may protect plants against these conditions by reflecting the light and decreasing plant temperature. This study was conducted to evaluate the protective effects of kaolin spraying on kernel yield and quality of four walnut cultivars and genotype. The experiment was conducted as a split-plot factorial design in time factor with four factors including irrigation levels (100% and 50% of regular irrigation), kaolin solution concentrations (0, 2.5, 5 and 7.5%), walnut varieties (‘Chandler’, ‘Franquette’, ‘K72’ and ‘SG’) in two consecutive years (2012–2013). By increasing the kaolin concentration under well-watered irrigation, gas exchange, chlorophyll concentration, leaf potassium content, and kernel quality were improved. Moreover, increasing the kaolin concentration reduced sunburn and leaf temperature under different irrigation regimes. Based on results, genotypes ‘K72’ and ‘SG’ showed more severe sunburn symptoms. Water stress and no kaolin application had negative effect on the kernel color. Leaf temperature increased with reducing the irrigation and concentration of kaolin. Under water stress, ‘Chandler’ had the highest relative water content (58.25%) and ‘Franquette’ had the lowest RWC and therefore considered as the most drought sensitive cultivar. The lowest fruits sunburn in ‘Franquette’, was related to the thickness of its fruits’ husk. In general, the foliar application of kaolin 5% and 7.5% alleviated the negative effect of drought stress and improved the walnut kernels quality under water deficit condition by improving chlorophyll content, RWC, and gas exchange and reducing leaf temperature.

Extreme high-temperature stress (HTS) associated with climate change poses potential threats to wheat grain yield and quality. Wheat grain protein concentration (GPC) is a determinant of wheat quality for human nutrition and is often neglected in attempts to assess climate change impacts on wheat production. Crop models are useful tools for quantification of temperature impacts on grain yield and quality. Current crop models either cannot simulate or can simulate only partially the effects of HTS on crop N dynamics and grain N accumulation. There is a paucity of observational data on crop N and grain quality collected under systematic HTS scenarios to develop algorithms for model improvement as well as evaluate crop models. Two-year phytotron experiments were conducted with two wheat cultivars under HTS at anthesis, grain filling, and both stages. HTS significantly reduced total aboveground N and increased the rate of grain N accumulation, while total aboveground N and the rate of grain N accumulation were more sensitive to HTS at anthesis than at grain filling. The observed relationships between total aboveground N, rate of grain N accumulation, and HTS were quantified and incorporated into the WheatGrow model. The new HTS routines improved simulation of the dynamics of total aboveground N, grain N accumulation, and GPC by the model. The improved model provided better estimates of total aboveground N, grain N accumulation, and GPC under HTS (the normalized root mean square error was reduced by 40%, 85%, and 80%, respectively) than the original WheatGrow model. The improvements in the model enhance its applicability to the assessment of climate change effects on wheat grain quality by reducing the uncertainties of simulating N dynamics and grain quality under HTS.

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

Some cucurbit plants (Cucumis sativus L., Cucurbita pepo L., Cucumis melo L. and Citrillus lanatus L.) were used for investigating some physiological changes and protein patterns under heat stress in plants. Leaf samples were exposed tohigh temperatures as follows 35, 40, 45, 50, 55 and 60°C. Percentage of ion leakage, chlorophyll content, leaf relative water content (RWC) and loss of turgidity, total soluble protein (TSP) content and protein profiles were determined in leaf samples kept at each temperature stage for 30 minutes. Ion leakage was increased especially 55 and 60°C in all cucurbits parallel to the temperature increasement. Total chlorophyll content was decreased slightly in both cucumber cultivars, zucchini, in both melon cultivars and watermelon due to high temperatures. The RWC of cucurbits was decreased on the contrary of the loss of turgidity, which was parallel to the increment of temperatures. While the TSP content in cucumber was decreased with temperature increasement, it was not changed in zucchini and watermelon. In melon cultivars TSP was not noticeably changed until 55°C, but significantly decreased at 60°C. When the SDS-PAGE profiles of cucurbits were examined, many protein bands were observed with sizes ranging from 6.5 kDa to 211 kDa.

NNew data on germ growth processes of dill seeds formed at the first and second branching orders after exposure to short-term heat stress (40 °C) are presented. Morphometric method and analysis of dill seed embryo growth in dynamics were used. The studies were carried out in 20152017 at the All-Russian Research Institute of Vegetable Growing, a branch of FSBSI FSCVG. Seeds of dill (Anethum graveolens L.) of the variety Centaurus from the first and second branching orders were the object of research. First, seeds were germinated in a thermostat. Then, swollen roots were exposed to a temperature of 40 °C according to the experiment scheme: 0 (control); 1; 2; 3; 4 and 5 days. After incubation, the seeds were transferred to standard conditions (temperature 20 °C) and germinated in Petri dishes on filter paper without light for 21 days. Germ size was measured using image analysis software. Critical embryo length and degree of underdevelopment were determined, and the ratio of embryo length to endosperm length (I Z/E) was calculated. Logistic regression with four parameters: b, c, d, e., was used to construct a germ growth curve. The relationship between the parameters was assessed using Pearson correlation analysis. The differences were considered statistically significant at P≤0.05. The duration of temperature action, which has an inhibitory effect on embryo growth, germination rate, the number of germinated seeds, were revealed. It was found that the embryos of seeds obtained from different branching orders have different sizes and have different intensity of growth under stress and standard conditions. It was shown that the effect of brief temperature (40 °C) on embryo growth depends on branching order and that embryos of seeds of the second branching order are more sensitive to high temperature. Morphometric parameters of the source were shown to play a critical role in the ability of dill seeds to resist the effect of temperature stressor during germination.

Gibberellic acid is an essential growth promoter that aids in the systematic plant growth. Studies on the impact of GA3 during cold period discovered a positive effect on the growth of rice plants. The current study evaluated the impact of various concentrations of GA3 on the yielding attributes of rice during cold stress in the rice varities, JGL 1804, BPT 5204, and RNR 15048. All the quantitative traits showed significant variation among the genotypes and treatments. Gibberellins applied at low concentrations during seedling stage (1, 2 or 3 gm/200 m2 of nursery area) revealed higher quantitative trait values compared to higher concnetartions (5 and 10 gm). Among all the three varities, RNR 15048 was found to be the best variety than the others in terms of yielding triats. Therefore, GA3 applied at a concentration of 1gm, 2gm or 3gm promotes the rice plant growth during cold periods and results in higher yield. Among these, 2 gm of GA3 for 200 m2 of nurcessary area was found to be the best in aiding the crop growth during cold phase.

Bu çalışmada, Ankara koşullarında yetiştirilen Trakya İlkeren üzüm çeşidinde kaolin partikül film (PF) uygulamasının sofralık kalite özellikleri üzerindeki etkisi incelenmiştir. Tane tutumundan başlayarak haftada birer kez olmak üzere yaprak yüzeyine (%3) toplam 3 uygulama yapılmıştır. Sofralık özellikler kapsamında omca verimi, olgunluk ölçütleri (SÇKM, pH, titrasyon asitliği, olgunluk indisi), salkım ve tane özellikleri ile tane kabuk rengi değerlendirilmiştir. PF uygulaması omca veriminde istatistik düzeyde önemli bir etki belirlenmemiştir. Omca verimi kontrol (K) grubunda 3.60 kg, PF uygulamasında ise 3.93 kg olarak belirlenmiştir. Olgunluk ölçütlerinden SÇKM ve olgunluk indisi PF uygulamasından olumlu etkilenmiştir. SÇKM Kontrol grubunda 19.45 oBx, PF uygulamasında 20.68 oBx olarak belirlenmiştir. SÇKM artışına bağlı olarak olgunluk indisi (%) 30.30’dan (K) 35.28’e (PF) yükselmiştir. pH ve asitlik düzeylerinde önemli bir etki belirlenmemiştir. Salkım boyu ve ağırlığında önemli artışlar sağlanmış, salkım boyu 17.14 cm’den (K) 19.02 cm’ye (PF) yükselirken, salkım ağırlığı 314.48 g’dan (K) 357.47 g’a (PF) yükselmiştir. Tane ağırlığı, eni, boyu ve sertliğinde önemli değişim belirlenmemiştir. CIRG indeksine göre, PF uygulaması tane kabuğunda renk yoğunluğunun artışına da katkı sağlamıştır. Sonuç olarak, partikül film uygulamasının yoğun güneşlenme ve yüksek sıcaklık koşullarında yetiştirilen Trakya İlkeren çeşidinde sofralık özelliklerin geliştirilmesine katkı sağladığı sonucuna ulaşılmıştır., In this study, the effects of foliar kaolin particle film treatment (PF) on some table grape quality characteristics of cv. Trakya Ilkeren grown in Ankara conditions were investigated. The application of kaolin particle film (3%) was started just after fruit set. Treatments were repeated weekly for three weeks. Yield per vine was found to be 3.60 kg in Control (C) and 3.93 kg in PF treatment. No significant effect of PF treatment on grape yield was determined. TSS and maturity index were affected positively by PF treatment. TSS was determined as 19.45oBx and 20.68oBx in C and PF treatment respectively. The maturity index (%) increased from 30.30 (C) to 35.28 (PF) due to the increase in TSS. No differences in pH and titratable acidity were observed between PF and C. While cluster weight increased from 314.48 g (C) to 357.47 g (PF), cluster length increased from 17.14 cm (C) to 19.02 cm (PF). No significant change in cluster width, berry weight, width, length and berry firmness were determined. More intense skin color was obtained from PF treatment according to CIRG index. Considering the findings, it was concluded that PF treatment led to the development in quality attributes of cv. Trakya Ilkeren grown under high solar radiation and temperature stress.

Photosynthetic capacity and photosystem II (PSII) activity decreased with increasing temperature, whereas antioxidant enzyme activity showed the opposite trend. High temperature stress induced a significant increase in Φf,D, and D1 protein turnover rate. Photosynthetic capacity, PSII activity, and antioxidant enzyme levels in plants treated at 35 and 40°C were restored to control levels upon stress relief, whereas those in plants grown at 45℃ were only partially restored. Therefore, the temperature limit for heat tolerance in Parthenocissus quinquefolia is between 40 and 45℃. Further, it was observed that antioxidant enzymes were crucial for high-temperature stress resistance in P. quinquefolia, with DEGP1 protein playing a major role in the rapid turnover of D1 protein for PSII repair. Bangladesh J. Bot. 50(2): 433-436, 2021 (June)

Temperature stress is a major concern in the agricultural practices due to the changing global climatic condition. The present investigation was conducted to evaluate cold and heat tolerant ability of few boro rice cultivars of Assam, India. Based on the different morpho-physiological responses under heat and cold stresses, 27 boro rice cultivars showed varying degrees of susceptibility. The total stress response index (TSRI) calculated on the basis of morpho-physiological parameters identified Buro as the most tolerant variety under both cold and heat stress. In contrast, Disang and Swarnabh were found to be the most susceptible cultivars under both the stresses. Our findings suggest that morpho-physiological traits are useful in screening rice varieties under environmental stress and TSRI can prove to be a suitable marker for developing promising heat and cold tolerant rice varieties in further rice breeding programs.

A pot experiment was carried out with six chickpea genotypes viz. KPG-59, IPC-2013-74 and NDG-15-6 (tolerant group); and KWR-108, BG-3075 and BG-3076 (susceptible group) to study the responses of these genotypes under salinity stress (4.20 dSm-1) with normal sowing, high temperature (HT) stress with late sowing and their combination (saline soil + late sowing), and compared with control (non-stress) condition based on several physio-biochemical traits such as malondialdehyde content (MDA), membrane stability index (MSI), relative water content (RWC) and proline in leaf at reproductive stage; and seed yield after harvesting. Both salinity and HT individually and in combination significantly affected the traits studied. Among the parameters, MDA increased under stress treatments over control, while MSI and RWC decreased for the same. However, combined stress exhibited hypo-additive effects for these parameters which might be due to developed cross-tolerance while facing salinity and HT stress in sequence. Increase in proline content under stress over control is an indication of osmotic adjustment in response to stress. These results might be good criteria in development of genotypes with improved response in terms of physio-biochemical traits and yield.

We live in the times of climate change when global temperatures are constantly rising. The impacts of climate change will also be felt in agriculture in Slovakia: increased productivity and yields in colder areas, reduced production in warmer areas due to temperature stress, risk of erosion as a result of more extreme weather conditions (stronger winds, more intense precipitation), the occurrence of new pests etc. Hence, we should be prepared for adaptation measures that would help mitigate it. The aim of this paper is to present the impacts of climate change on agriculture and land, and to offer adaptation measures, and show the prognosis of the climate indicator Ts >10 °C from now until 2100.

This study was carried out to assess antioxidant activities and defense role of putrescine and proline in leaves of three Citrus species under low temperature stress. Branches of three Citrus species (C. reticulata L., C. sinensis L. and C. paradisi L.), sprayed with putrescine 0, 5, 10 mM and proline 0, 15, 20 mM. 24 h after application, containers containing treated shoots exposed to temperatures 1, − 1 and − 3 °C for six hours. The amount of hydrogen peroxide, flavonoids, phenolic compounds and antioxidant capacity increased with temperature reduction to − 3 °C. HPLC analysis showed that low temperature (− 3 °C) induces the levels of Gamma Aminobutyric Acid (GABA) in leaves of all species. The comparison of the HPLC patterns of the three species showed that GABA levels in treated leaves increased than control. The application of different concentrations of putrescine and proline decreased production of hydrogen peroxide but improved antioxidative activities of leaves under low temperatures. Putrescine 10 mM and proline 20 mM showed the highest effects than the other levels. The highest value of hydrogen peroxide was observed in leaves of control (putrescine and proline 0 mM) under − 3 °C but its lowest level was seen in leaves treated with proline 20 mM and putrescine 10 mM in all three species of Citrus. The highest level of phenolic compounds, flavonoids and antioxidant capacity were observed in leaves treated with putrescine 10 mM and proline 20 mM at − 3 °C. Putrescine 10 mM and proline 20 mM showed the highest impact on reduction of the damages caused by low temperature stress.

The Hylocereus species that are grown as exotic fruit crops are very often farmed under marginal agronomic conditions, which may include exposure to high temperatures. Here we present a pioneering investigation of grafting as an agro-technique to improve heat tolerance in Hylocereus. To this end, we studied the diploid species H. undatus, the tetraploid H. megalanthus and its di-haploid gamete-derived line 2719, and the interspecific-interploid tetraploid Z-10, all grafted onto H. undatus as the rootstock. Self-grafted, grafted and non-grafted plants were acclimated for one week (to obtain baseline values) and then exposed to heat stress (45/35 °C day/night) for three days, followed by a one-week recovery period under optimal temperatures (30/22 °C). A comparison of the physiological, biochemical and molecular performances of the grafted and self-grafted plants under heat stress and during the recovery period vs those of non-stressed plants (control; 30/22 °C) showed that the grafted and self-grafted plants performed better in most of the assessments: grafted and self-grafted plants recovered more rapidly from the heat stress and suffered far less stem damage. An unexpected – but important – finding that may have implications for other crop was that the self-grafted plants showed better performance than non-grafted plants throughout the trial. Our findings provide support for grafting as a strategy for coping with the stress induced by extremely high temperatures. This study thus paves the way for further investigations of grafting in Hylocereus as a valuable technique that will maintain crop productivity in the face of increasing worldwide temperatures.

Resilience to climate change depends on a species' adaptive potential and phenotypic plasticity. The latter can enhance survival of individual organisms during short periods of extreme environmental perturbations, allowing genetic adaptation to take place over generations. Along the U.S. East Coast, estuarine‐dependent spotted seatrout (Cynoscion nebulosus) populations span a steep temperature gradient that provides an ideal opportunity to explore the molecular basis of phenotypic plasticity. Genetically distinct spotted seatrout sampled from a northern and a southern population were exposed to acute cold and heat stress (5 biological replicates in each treatment and control group), and their transcriptomic responses were compared using RNA‐sequencing (RNA‐seq). The southern population showed a larger transcriptomic response to acute cold stress, whereas the northern population showed a larger transcriptomic response to acute heat stress compared with their respective population controls. Shared transcripts showing significant differences in expression levels were predominantly enriched in pathways that included metabolism, transcriptional regulation, and immune response. In response to heat stress, only the northern population significantly upregulated genes in the apoptosis pathway, which could suggest greater vulnerability to future heat waves in this population as compared to the southern population. Genes showing population‐specific patterns of expression, including hpt, acot, hspa5, and hsc71, are candidates for future studies aiming to monitor intraspecific differences in temperature stress responses in spotted seatrout. Our findings contribute to the current understanding of phenotypic plasticity and provide a basis for predicting the response of a eurythermal fish species to future extreme temperatures.

Fly ash (FA) is an environmentally hazardous industrial solid waste. High FA replacement levels on properties of concrete with low w/b have been widely investigated, however, studies on the thermal cracking behavior of HVFA concrete with high w/b are lacking. This paper investigated the effect of high volume fly ash (HVFA) on mechanical properties and thermal cracking resistance of concrete with a high w/b of 0.45 using temperature stress testing machine (TSTM). An adiabatic curing condition during the temperature rise stage and a rapid cooling during the temperature drop stage were applied on test specimens. The effectiveness of concrete with different FA replacement levels (0%, 20%, 50% and 80%) on the thermal cracking potential of concrete under a restraint degree of 100% has been addressed. Results showed that the mechanical properties of concrete mixture decreased with the increasing FA replacement level; the ratio of creep-to-free strain (i.e., relaxation behavior) of concrete mixture decreased when the FA replacement level reached 20%, and converted to increase for the FA replacement level ranging from 50% to 80%; FA replacement level with 50% showed a desirable effect on the thermal cracking resistance enhancement of high w/b concrete mixture regarding restrained cracking control.