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Heat stress strongly triggers the nuclear localization of the molecular chaperone HSP70. Hikeshi functions as a unique nuclear import carrier of HSP70. However, how the nuclear import of HSP70 is activated in response to heat stress remains unclear. Here, we investigated the effects of heat on the nuclear import of HSP70. In vitro transport assays revealed that pretreatment of the test samples with heat facilitated the nuclear import of HSP70. Furthermore, binding of Hikeshi to HSP70 increased when temperatures rose. These results indicated that heat is one of the factors that activates the nuclear import of HSP70. Previous studies showed that the F97A mutation in Hikeshi in an extended loop induced an opening in the hydrophobic pocket and facilitated the translocation of Hikeshi through the nuclear pore complex. We found that nuclear accumulation of HSP70 occurred at a lower temperature in cells expressing the Hikeshi‐F97A mutant than in cells expressing wild‐type Hikeshi. Collectively, our results show that the movement of the extended loop may play an important role in the interaction of Hikeshi with both FG (phenylalanine‐glycine)‐nucleoporins and HSP70 in a temperature‐dependent manner, resulting in the activation of nuclear import of HSP70 in response to heat stress. [ABSTRACT FROM AUTHOR]

Introduction: Heat stress negatively affects wheat production in several ways, mainly by reducing growth rate, photosynthetic capacity and reducing spike fertility. Modeling stress response means analyzing simultaneous relationships among traits affecting the whole plant response and determinants of grain yield. The aim of this study was to dissect the diverse impacts of heat stress on key yield traits and to identify the most promising sources of alleles for heat tolerance. Methods: We evaluated a diverse durum wheat panel of 183 cultivars and breeding lines from worldwide, for their response to long-term heat stress under field conditions (HS) with respect to non stress conditions (NS), considering phenological traits, grain yield (GY) and its components as a function of the timing of heat stress and climatic covariates. We investigated the relationships among plant and environmental variables by means of a structural equation model (SEM) and Genetic SEM (GSEM). Results: Over two years of experiments at CENEB, CIMMYT, the effects of HS were particularly pronounced for the normalized difference vegetation index, NDVI (-51.3%), kernel weight per spike, KWS (-40.5%), grain filling period, GFP (-38.7%), and GY (-56.6%). Average temperatures around anthesis were negatively correlated with GY, thousand kernel weight TKW and test weight TWT, but also with spike density, a trait determined before heading/anthesis. Under HS, the correlation between the three major determinants of GY, i.e., fertile spike density, spike fertility and kernel size, were of noticeable magnitude. NDVI measured at medium milk-soft dough stage under HS was correlated with both spike fertility and grain weight while under NS it was less predictive of grain weight but still highly correlated with spike fertility. GSEM modeling suggested that the causal model of performance under HS directly involves genetic effects on GY, NDVI, KWS and HD. Discussion: We identified consistently suitable sources of genetic resistance to heat stress to be used in different durum wheat pre-breeding programs. Among those, Desert Durums and CIMMYT'80 germplasm showed the highest degree of adaptation and capacity to yield under high temperatures and can be considered as a valuable source of alleles for adaptation to breed new HS resilient cultivars. [ABSTRACT FROM AUTHOR]

ABSTRACT: Rising temperatures and intensified agricultural practices have heightened heat stress (HS)-related challenges in poultry farming, notably heat-induced sudden death in chickens. Wenchang chickens, recognized for their heat resistance, have emerged as the potential candidates for improving the economic efficiency of poultry farming. The adrenal gland plays a crucial role in preventing HS-induced heart failure sudden death by secreting hormones. However, little is known about the damage to and resilience of Wenchang chicken adrenal glands during HS. In this study, 34 healthy Wenchang chickens with similar weights were selected for formal experimentation, with 10 as the control group (Con). Following a single exposure to acute HS of 42 ± 1°C and 65% relative humidity for 5 h, 15 deceased individuals formed the HS death (HSD) group, and 9 survived comprised the HS survival (HSS) group. ELISA revealed significant higher (P < 0.05) levels of COR and NE in the HSS and the lowest levels of CORT and EPI in the HSD. Histopathological analysis indicated major degeneration in HSS cortical and chromaffin cells and extensive cell necrosis (nuclear pyknosis) in HSD. Proteomic analysis identified 572 DEPs in HSD vs. Con and 191 DEPs in HSS vs. Con. Bioinformatics highlighted ER protein processing, especially ERAD as a key pathway for heat stress resistance (HSR) in the adrenal gland, with HSPH1, DNAJA1, HSP90AA1, HSPA8 and HERPUD1 identified as regulating key molecules. Western blotting validated significantly higher (P < 0.01) protein levels in both HSS and HSD compared to the Con. Immunohistochemical staining showed increased cytoplasmic HSPH1-positive signal intensity under HS and enhanced HSP90AA1 nuclear signals, strongest in HSS. In summary, HS induces pathological damage in Wenchang chicken adrenal glands, affecting hormone secretion, and various heat shock proteins play crucial roles in cellular resistance. These results elucidate the biological basis of HSR in Wenchang chickens from the perspective of the adrenal gland and provide necessary research foundations for enhancing economic performance of various broilers in high-heat environments and screening drugs for HS treatment.

Evaluation of the effects of feeding NutraGen supplement (NutraGen, NTG; Phibro Animal Health, Teaneck, NJ, USA) on growth performance, energetic efficiency, carcass characteristcs, and characteristics of digestion in calf-fed Holstein steers fed a conventional growing-finishing diet. Trial 1 evaluated growth performance, dietary energetics and carcass characteristics. Two hundred Holstein steer calves (134 ± 5 kg) were blocked by initial body weight (BW) and randomly assigned to 40 pens (5 steers/pen). Dietary treatments consisted of a steam-flaked corn-based growing-finishing diet supplemented with 0, 0.2, 0.4, or 0.6% NTG (DM basis). In trial 2, four Holstein steers (170 ±6 kg) with cannulas in the rumen and proximal duodenum were used in a 4 × 4 Latin square experiment to evaluate digestibility and ruminal characteristics using the treatments from trial 1. Compared to non-supplemented cattle, NTG increased BW (2.0%, P = 0.02) and tended to increase ADG (3.6%, P = 0.07) during the initial 56 d period. However, there were no treatment effects on overall growth performance and efficiency of dietary energy utilization after the first 56 days (P > 0.10). Supplementation of NTG increased (linear effect; P ≤ 0.03) longissimus muscle area and kidney, pelvic, and heart fat. There was no effect (P ≥ 0.05) of NTG supplementation on other carcass characteristics, liver abscess incidence, or liver abscess scars. Supplementation decreased the molar proportion of ruminal propionate (P = 0.05) and tended to increase acetate:propionate molar ratio (P = 0.09). However, there was no effect of NTG supplementation on ruminal and total tract diet digestion. NTG increased performance of Holstein steers during the first 56 d on feed in the feedlot. In addition, the steers had an increase in KPH fat and LM area, indicating that the additive induced change in metabolism of the steers.

Global warming is a key challenge subjecting animals to heat stress conditions resulting in multiple physiological alterations in tropical climate. Dietary approach seems to be the more friendly approach to curb the adverse effects of heat stress in rabbits. Some herbs have been categorized to have high potential for promotion of immune responses for amelioration of heat stress. Thus, this research aims to evaluate the potential of Mistletoe (Viscum album), Moringa (Moringa oleifera) and Phyllanthus (Phyllanthus amarus) leaf meal as herbal supplements for the alleviation of heat stress in female rabbits by measuring improvement in sex and stress hormonal responses in serum biochemistry. 80 Rabbit does were exposed to 4 dietary groups supplemented with each of Mistletoe, Moringa, Phyllanthus and a control in an 84-day trial at the summit of thermal stress in South west Nigeria. Growth indices were monitored throughout the study, blood samples were compiled at the end of the trial to assess serum biochemistry, stress and sex hormonal responses of the Does using standard protocols. The results revealed that final weight and weight gain of Does fed on Phyllanthus were significantly (p < 0.05) higher (11.46% and 14.25%, respectively) than Does on control. The herbal supplements enhance glucose, protein, albumin and globulin, reduced cholesterol, and creatinine of Does under heat stress conditions. Among the herbal treatment groups, mistletoe, moringa and phyllanthus had 12.42%, 18.39% and 16.90%, respectively, lower corticosterone than control groups which had 39.76ng/ml. Triiodothyronine of Does fed control were significantly (p < 0.05) lower than Does on Moringa oleifera and Phyllanthus amarus supplements. Estradiol and Follicle stimulating hormone of rabbit Does fed on moringa supplement were significantly (p < 0.05) higher than other treatments. In conclusion, the herbal supplements tend to mitigate the detrimental outcome of thermal stress on Does by suppressing stress hormones. Moringa oleifera and Phyllanthus amarus enhanced sex hormones while Phyllanthus amarus confered growth promoting effects on the Does.

Sweet potato is one of the important tropical tuber crops across the world. This review analyzes the studies on the climate resilience of sweet potato to various environmental parameters, the impact of climate change on its yield, and geographical suitability to exploit more about this crop and find out the knowledge gap in its existing research. Drought tolerance studies indicate the suitability of sweet potato in drought‐prone areas in terms of their survival rate, and their leaves can tolerate up to a wilting point of −1.3 MPa. The optimum night and daytime temperatures for sweet potato are 18°C and 28°C. There are 82 crop varieties available globally with heat‐stress tolerance without compromising the yield. The elevated atmospheric CO2 enhanced the growth and yield of sweet potato and increased the water use efficiency. The salinity tolerance of sweet potato is observed as 11 dS m−1, and it is superior to other major food crops. Sweet potato's ozone tolerance is higher than other crops (59 ppb). The impact studies on crop yield and geographical suitability also recommend its superiority to other major food crops with similar crop duration. As an outcome of this study, further research is needed to explore this crop as sweet potato can substitute for major food grain crops in developing countries regarding food, feed, medicine, and fuel. Research on value‐added products and their marketing is another area that needs immediate attention. Studies must exploit sweet potato leaves to ensure nutritional security in developing countries. The researchers also need to focus on developing climate‐resilient varieties to ensure a continuous supply of planting materials to needy people to ensure food security. This review also demands more studies on the modeling of sweet potato worldwide to issue crop yield forecasts and monitor the spatial distribution of its major pests worldwide. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Animal & Poultry Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

IntroductionHeat stress negatively affects wheat production in several ways, mainly by reducing growth rate, photosynthetic capacity and reducing spike fertility. Modeling stress response means analyzing simultaneous relationships among traits affecting the whole plant response and determinants of grain yield. The aim of this study was to dissect the diverse impacts of heat stress on key yield traits and to identify the most promising sources of alleles for heat tolerance.MethodsWe evaluated a diverse durum wheat panel of 183 cultivars and breeding lines from worldwide, for their response to long-term heat stress under field conditions (HS) with respect to non stress conditions (NS), considering phenological traits, grain yield (GY) and its components as a function of the timing of heat stress and climatic covariates. We investigated the relationships among plant and environmental variables by means of a structural equation model (SEM) and Genetic SEM (GSEM). ResultsOver two years of experiments at CENEB, CIMMYT, the effects of HS were particularly pronounced for the normalized difference vegetation index, NDVI (-51.3%), kernel weight per spike, KWS (-40.5%), grain filling period, GFP (-38.7%), and GY (-56.6%). Average temperatures around anthesis were negatively correlated with GY, thousand kernel weight TKW and test weight TWT, but also with spike density, a trait determined before heading/anthesis. Under HS, the correlation between the three major determinants of GY, i.e., fertile spike density, spike fertility and kernel size, were of noticeable magnitude. NDVI measured at medium milk-soft dough stage under HS was correlated with both spike fertility and grain weight while under NS it was less predictive of grain weight but still highly correlated with spike fertility. GSEM modeling suggested that the causal model of performance under HS directly involves genetic effects on GY, NDVI, KWS and HD.DiscussionWe identified consistently suitable sources of genetic resistance to heat stress to be used in different durum wheat pre-breeding programs. Among those, Desert Durums and CIMMYT’80 germplasm showed the highest degree of adaptation and capacity to yield under high temperatures and can be considered as a valuable source of alleles for adaptation to breed new HS resilient cultivars.

Climate adaptation decision making can be informed by a quantification of current and future climate risk. This is important for understanding which populations and/or infrastructures are most at risk in order to prioritise adaptation action. When assessing the risk of overheating in buildings, many studies use advanced building models to comprehensively represent the vulnerability of the building to overheating, but often use a limited representation of the meteorological (hazard) information which does not vary realistically in space. An alternative approach for quantifying risk is to use a spatial risk assessment framework which combines information about hazard, exposure and vulnerability to estimate risk in a spatially consistent way, allowing for risk to be compared across different locations. Here we present a novel application of an open-source CLIMADA-based spatial risk assessment framework to an ensemble of climate projections to assess overheating risk in ∼20,000 schools in England. In doing so, we demonstrate an approach for bringing together the advantages of open-source spatial risk assessment frameworks, data science techniques, and physics-based building models to assess climate risk in a spatially consistent way, allowing for the prioritisation of adaptation action in this vulnerable young population. Specifically, we assess the expected number of days each school overheats (internal operative temperature exceeds a high threshold) in a school-year based on three global warming levels (recent past, 2 °C and 4 °C warmer than pre-industrial). Our results indicate an increase in this risk in future warmer climates, with the relative frequency of overheating at internal temperatures in excess of 35 °C increasing more than at 26 °C. Indeed, this novel demonstration of the approach indicates that the most at-risk schools could experience up to 15 school days of internal temperature in excess of 35 °C in an average year if the climate warms to 2 °C above pre-industrial. Finally, we demonstrate how the spatial consistency in the output risk could enable the prioritisation of high risk schools for adaptation action.

Cattle control body temperature in a narrow range over varying climatic conditions. Endogenous body heat is generated by metabolism, digestion and activity. Radiation is the primary external source of heat transfer into the body of cattle. Cattle homeothermy uses behavioural and physiological controls to manage radiation, convection, conduction, and evaporative exchange of heat between the body and the environment, noting that evaporative mechanisms almost exclusively transfer body heat to the environment. Cattle control radiation by shade seeking (hot) and shelter (cold) and by huddling or standing further apart, noting there are intrinsic breed and age differences in radiative transfer potential. The temperature gradient between the skin and the external environment and wind speed (convection) determines heat transfer by these means. Cattle control these mechanisms by managing blood flow to the periphery (physiology), by shelter‐seeking and standing/lying activity in the short term (behaviourally) and by modifying their coats and adjusting their metabolic rates in the longer term (acclimatisation). Evaporative heat loss in cattle is primarily from sweating, with some respiratory contribution, and is the primary mechanism for dissipating excess heat when environmental temperatures exceed skin temperature (~36°C). Cattle tend to be better adapted to cooler rather than hotter external conditions, with Bos indicus breeds more adapted to hotter conditions than Bos taurus. Management can minimise the risk of thermal stress by ensuring appropriate breeds of suitably acclimatised cattle, at appropriate stocking densities, fed appropriate diets (and water), and with access to suitable shelter and ventilation are better suited to their expected farm environment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Animal & Poultry Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Global warming is a major challenge for plant survival and growth. Understanding the molecular mechanisms by which higher plants sense and adapt to upsurges in the ambient temperature is essential for developing strategies to enhance plant tolerance to heat stress. Here, we designed a heat-responsive Arabidopsis thaliana reporter line that allows an in-depth investigation of the mechanisms underlying the accumulation of protective heat-shock proteins (HSPs) in response to high temperature. Methods A transgenic Arabidopsis thaliana reporter line named “Heat-Inducible Bioluminescence And Toxicity” (HIBAT) was designed to express from a conditional heat-inducible promoter, a fusion gene encoding for nanoluciferase and d-amino acid oxidase, whose expression is toxic in the presence of d-valine. HIBAT seedlings were exposed to different heat treatments in presence or absence of d-valine and analyzed for survival rate, bioluminescence and HSP gene expression. Results Whereas at 22 °C, HIBAT seedlings grew unaffected by d-valine, and all survived iterative heat treatments without d-valine, 98% died following heat treatments on d-valine. The HSP17.3B promoter was highly specific to heat as it remained unresponsive to various plant hormones, Flagellin, H2O2, osmotic stress and high salt. RNAseq analysis of heat-treated HIBAT seedlings showed a strong correlation with expression profiles of two wild type lines, confirming that HIBAT does not significantly differ from its Col-0 parent. Using HIBAT, a forward genetic screen revealed candidate loss-of-function mutants, apparently defective either at accumulating HSPs at high temperature or at repressing HSP accumulation at non-heat-shock temperatures. Conclusion HIBAT is a valuable candidate tool to identify Arabidopsis mutants defective in the response to high temperature stress. It opens new avenues for future research on the regulation of HSP expression and for understanding the mechanisms of plant acquired thermotolerance.

Mechanisms aimed at recovering from heat-induced damages are closely associated with the ability of ectotherms to survive exposure to stressful temperatures. Autophagy, a ubiquitous stress-responsive catabolic process, has recently gained renewed attention as one of these mechanisms. By increasing the turnover of cellular structures as well as the clearance of long-lived protein and protein aggregates, the induction of autophagy has been linked to increased tolerance to a range of abiotic stressors in diverse ectothermic organisms. However, whether a link between autophagy and heat-tolerance exists in insect models remains unclear despite broad ecophysiological implications thereof. Here, we explored the putative association between autophagy and heat-tolerance using Drosophila melanogaster as a model. We hypothesized that (i) heat-stress would cause an increase of autophagy in flies' tissues, and (ii) rapamycin exposure would trigger a detectable autophagic response in adults and increase their heat-tolerance. In line with our hypothesis, we report that flies exposed to heat-stress present signs of protein aggregation and appear to trigger an autophagy-related homoeostatic response as a result. We further show that rapamycin feeding causes the systemic effect associated with target of rapamycin (TOR) inhibition, induces autophagy locally in the fly gut, and increases the heat-stress tolerance of individuals. These results argue in favour of a substantial contribution of autophagy to the heat-stress tolerance mechanisms of insects. [ABSTRACT FROM AUTHOR]

The main problem in dairy herds is reproductive disorders, which are influenced by many factors, including temperature. Heat stress reduces the quality of oocytes and their maturation through the influence of, e.g., mitochondrial function. Mitochondria are crucial during oocyte maturation as well as the process of fertilization and embryonic development. Disturbances related to high temperature will be increasingly observed due to global warming. In present studies, we have proven that exposure to high temperatures during the cleaving of embryos statistically significantly (at the level of p < 0.01) reduces the percentage of oocytes that cleaved and developed into blastocysts eight days after insemination. The study showed the highest percentage of embryos that underwent division in the control group (38.3 °C). The value was 88.10 ± 6.20%, while the lowest was obtained in the study group at 41.0 °C (52.32 ± 8.40%). It was also shown that high temperature has a statistically significant (p < 0.01) effect on the percentage of embryos that developed from the one-cell stage to blastocysts. The study showed that exposure to a temperature of 41.0 °C significantly reduced the percentage of embryos that split relative to the control group (38.3 °C; 88.10 ± 6.20%). Moreover, it was noted that the highest tested temperature limits the development of oocytes to the blastocyst stage by 5.00 ± 9.12% compared to controls (33.33 ± 7.10%) and cleaved embryos to blastocysts by 3.52 ± 6.80%; the control was 39.47 ± 5.40%. There was also a highly significant (p < 0.0001) effect of temperature on cytoplasmic ROS levels after 6 and 12 h IVM. The highest level of mitochondrial ROS was found in the group of oocytes after 6 h IVM at 41.0 °C and the lowest was found in the control group. In turn, at 41.0 °C after 12 h of IVM, the mitochondrial ROS level had a 2.00 fluorescent ratio, and the lowest in the group was 38.3 °C (1.08). Moreover, with increasing temperature, a decrease in the expression level of both LC3 and SIRT1 protein markers was observed. It was proved that the autophagy process was impaired as a result of high temperature. Understanding of the cellular and molecular responses of oocytes to elevated temperatures will be helpful in the development of heat resistance strategies in dairy cattle. [ABSTRACT FROM AUTHOR]

Background: Global warming is a major challenge for plant survival and growth. Understanding the molecular mechanisms by which higher plants sense and adapt to upsurges in the ambient temperature is essential for developing strategies to enhance plant tolerance to heat stress. Here, we designed a heat-responsive Arabidopsis thaliana reporter line that allows an in-depth investigation of the mechanisms underlying the accumulation of protective heat-shock proteins (HSPs) in response to high temperature. Methods: A transgenic Arabidopsis thaliana reporter line named "Heat-Inducible Bioluminescence And Toxicity" (HIBAT) was designed to express from a conditional heat-inducible promoter, a fusion gene encoding for nanoluciferase and d-amino acid oxidase, whose expression is toxic in the presence of d-valine. HIBAT seedlings were exposed to different heat treatments in presence or absence of d-valine and analyzed for survival rate, bioluminescence and HSP gene expression. Results: Whereas at 22 °C, HIBAT seedlings grew unaffected by d-valine, and all survived iterative heat treatments without d-valine, 98% died following heat treatments on d-valine. The HSP17.3B promoter was highly specific to heat as it remained unresponsive to various plant hormones, Flagellin, H2O2, osmotic stress and high salt. RNAseq analysis of heat-treated HIBAT seedlings showed a strong correlation with expression profiles of two wild type lines, confirming that HIBAT does not significantly differ from its Col-0 parent. Using HIBAT, a forward genetic screen revealed candidate loss-of-function mutants, apparently defective either at accumulating HSPs at high temperature or at repressing HSP accumulation at non-heat-shock temperatures. Conclusion: HIBAT is a valuable candidate tool to identify Arabidopsis mutants defective in the response to high temperature stress. It opens new avenues for future research on the regulation of HSP expression and for understanding the mechanisms of plant acquired thermotolerance. [ABSTRACT FROM AUTHOR]

Egg quality is of economic consideration especially in thermally challenged confinements during table egg production and transportation. The effect of vitamin-C and folate on heat-stressed chickens’ egg quality and performance is aimed at overcoming the negative impact of exposure to increased environmental heat load at peak heat periods of the year using vitamin-C as ameliorative agent, and efficient utilization of consumed feed, using folate. This is in other to lay quality eggs and perform optimally. A total of 72 Isa Brown laying hens at 31 weeks of age were randomly divided into 4 treatment groups of 36 birds subdivided into 3 replicates and indicated as T1, T2, T3 and T4 while T1 served as the control treatment. The birds were housed in a deep litter pen and exposed to 3-hours additional heat generated with gas-powered burners, for four consecutive days of each week for a period of 12 weeks. The diets for T2, T3 and T4 were supplemented with 250 mg of vitamin-C, 250 mg of vitamin-C + 1 mg of folate and 300 mg of vitamin-C + 1 mg of folate per kg of feed respectively. The results showed that T4 had the highest egg weights (60.04 g), shell thickness (0.53 mm) and shell weights (7.80 g). The albumin weight (37.20 g), albumin height (6.80 mm) and yolk weight (14.70 g) were highest (P

More than one-half of the world’s cattle are maintained in hot environments, making heat stress a significant issue for the beef industry. Around $370 million is lost annually due to reduced performance due to heat stress, which has other detrimental impacts on cattle, such as decreased feed intake, fertility, and immune response. The assessment of hair glucocorticoids (hGC) serves as a valuable tool for evaluating chronic stress levels in beef cattle. Unlike traditional cortisol measurements, which provide only a glimpse of stress at a specific moment, hGCs offer a retrospective view of long-term stress exposure. This makes them particularly valuable for assessing chronic stress, which can profoundly impact animal health, welfare, and productivity. By quantifying hGC concentrations, we gain insights into the cumulative stress experienced by cattle over time, allowing for more comprehensive monitoring and management strategies. This study investigated the relationship between hGC concentrations and breed composition in beef cattle, specifically focusing on whether breed composition influences hGC concentrations after prolonged heat exposure. Animals from the University of Florida’s Multibreed Angus-Brahman herd were used. Hair samples were collected from 240 cows during the summer of 2017 and 2018, with breed compositions ranging from 100% Brahman to 100% Angus. Starting with a 4 mg hair sample, the hGC were extracted and analyzed with the Cortisol ELISA KIT (Neogen Corporation, Ayr, UK). An Analysis of Variance (ANOVA) was conducted to examine the relationship between hGC concentration, breed composition, and batch effect. The results indicated a significant effect of breed composition on hGC concentration (P-value 0.01406). These findings suggest that breed composition influences chronic stress during prolonged periods of heat exposure. However, individual factors like thermotolerance, health status, and social stress may also have a role in chronic stress levels. To better understand these factors, future steps will involve comparing the hGC concentration results between thermotolerant and non-thermotolerant animals. This comparison will provide insights into the potential differences in stress responses between cattle breeds adapted to hot environments and those less tolerant to heat stress. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of acute heat stress on the skeletal muscle epigenome using reduced representation bisulfite sequencing (RRBS). March-born crossbred (5/8 Red Angus, 3/8 Simmental) steers (n = 14; average body weight = 308.7 kg) were exposed to heat stress (HS) conditions of 35°C + 35% relative humidity (Temperature Humidity Index = 81) for 12h/d for 2 d (48 h). Longissimus dorsi samples were collected via biopsy and flash-frozen in liquid nitrogen immediately following the HS period at 48 h and from the contralateral longissimus dorsi 5 d later. DNA was isolated and underwent RRBS using 150 bp paired-end reads at an achieved average depth of 15.3 million reads/ sample. Reads were trimmed and mapped to a bisulfiteconverted bovine genome (ARSUCD1.2). Methylation calls were extracted and used to identify differentially methylated regions (DMRs) with methylkit in R comparing samples collected 5 d post-HS to those taken immediately post-48 h of HS. Differentially methylated regions (1,000 bp) had q < 0.05 and at least a 15% difference in methylation. There were 1,015 DMRs in genes. Hypomethylated DMRs 5 d post-HS included IGF1R, IGF2, IGF2BP1, IGFBP4, IGF2R, IKBKB, and IL34. Hypermethylated DMRs 5 d post-HS included FGF5, FGFR1, and FGFR3. There were 81 DMRs in putative promoter regions (2000 bp 5’ of a gene). MYLK2, SIGIRR, and 25 other genes had hypomethylated promoter regions. Genes that contained DMRs were used as input for DAVID to explore KEGG pathways. Enriched pathways (P < 0.1) included multiple hormone pathways, MAPK, PI3K-Akt, HIF-1, and VEGF. Hypomethylation of IGF-related genes and hypermethylation of FGF-related genes suggests impaired growth capacity post-HS, as does the enrichment of MAPK and PI3K-Akt pathways. Hypomethylation of SIGIRR’s promoter region, IL34 and IKBKB, indicates enhanced anti-inflammatory activity given their known regulation of inflammatory cytokine production. This, coupled with enrichment of the HIF-1 and VEGF pathways, suggests regulatory dampening of HS-induced oxidative stress. These findings reveal key regulatory changes in muscle growth, inflammatory response, and oxidative stress activity for cattle recovering from acute HS. Previous cattle skeletal muscle RNA studies predicted that HS altered metabolism, inflammation, and oxidative stress pathways, similar to the methylation results of this study. Overall, evidence suggests growth dysregulation, which may help explain observed HS-induced poor growth due to HS, as well as subsequent anti-inflammatory activity during recovery from HS. [ABSTRACT FROM AUTHOR]

Abiotic stresses (drought, heat) are one of the major impediments to enhancing the maize productivity of marginal farmers in the facet of climate change. The present study attempts to investigate the impact of heat-tolerant maize hybrid on yield and income in the Terai region of Nepal. This study uses cross-sectional farm household-level data collected in August 2021 from a randomly selected sample of 404 rural households. We used a doubly robust inverse probability weighted regression adjustment method to obtain reliable impact estimates. Adoption of heat-tolerant hybrid increases yields by 16% and income by 44% in the spring season (a stress condition). Overall, yield increases by 12%, net income by 31%, saving of 40% in seed costs, and per capita food expenditure increases by 8.50%. Hence a conducive environment must be created for scaling up heat-tolerant maize varieties to increase productivity, minimize risk, and transform of the maize sector.

The purpose of this study was to assess the reliability of blood biomarkers that can signify exercise-induced heat stress in hot conditions. Fourteen males completed two heat stress tests separated by 5–7 days. Venous blood was drawn pre- and post- heat stress for the concentration of normetanephrine, metanephrine, serum osmolality, copeptin, kidney-injury molecule 1, and neutrophil gelatinase-associated lipocalin. No biomarker, except copeptin, displayed systematic trial order bias (p ≥0.05). Normetanephrine, copeptin and neutrophil gelatinase-associated lipocalin presented acceptable reliability (CV range: 0.9–14.3%), while greater variability was present in metanephrine, osmolality and kidney-injury molecule 1 (CV range: 28.6–43.2%). Normetanephrine exhibited the largest increase (p<0.001) in response to heat stress (trial 1=1048±461 pmol. L-1 ; trial 2=1067±408 pmol. L-1), whilst kidney-injury molecule 1 presented trivial changes (trial 1=–4±20 ng. L-1 ; trial 2=2 ± 16 ng. L-1 , p >0.05). Normetanephrine, copeptin, and neutrophil gelatinase-associated lipocalin demonstrated good reliability and sensitivity to an acute bout of heat stress. These biomarkers may be suitable for application in laboratory and field research to understand the efficacy of interventions that can attenuate the risk of thermal injury whilst exercising in the heat. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are non-coding small RNAs that play crucial roles in plant development and stress responses and can regulate plant interactions with beneficial soil microorganisms such as arbuscular mycorrhizal fungi (AMF). To determine if root inoculation with distinct AMF species affected miRNA expression in grapevines subjected to high temperatures, RNA-seq was conducted in leaves of grapevines inoculated with either Rhizoglomus irregulare or Funneliformis mosseae and exposed to a high-temperature treatment (HTT) of 40 °C for 4 h per day for one week. Our results showed that mycorrhizal inoculation resulted in a better plant physiological response to HTT. Amongst the 195 identified miRNAs, 83 were considered isomiRs, suggesting that isomiRs can be biologically functional in plants. The number of differentially expressed miRNAs between temperatures was higher in mycorrhizal (28) than in non-inoculated plants (17). Several miR396 family members, which target homeobox-leucine zipper proteins, were only upregulated by HTT in mycorrhizal plants. Predicted targets of HTT-induced miRNAs in mycorrhizal plants queried to STRING DB formed networks for Cox complex, and growth and stress-related transcription factors such as SQUAMOSA promoter-binding-like-proteins, homeobox-leucine zipper proteins and auxin receptors. A further cluster related to DNA polymerase was found in R. irregulare inoculated plants. The results presented herein provide new insights into miRNA regulation in mycorrhizal grapevines under heat stress and can be the basis for functional studies of plant-AMF-stress interactions. [ABSTRACT FROM AUTHOR]

Codonopsis tangshen Oliv (C. tangshen) is a valuable traditional Chinese medicinal herb with tremendous health benefits. However, the growth and development of C. tangshen are seriously affected by high temperatures. Therefore, understanding the molecular responses of C. tangshen to high-temperature stress is imperative to improve its thermotolerance. Here, RNA-Seq analysis was performed to investigate the genome-wide transcriptional changes in C. tangshen in response to short-term heat stress. Heat stress significantly damages membrane stability and chlorophyll biosynthesis in C. tangshen, as evidenced by pronounced malonaldehyde (MDA), electrolyte leakage (EL), and reduced chlorophyll content. Transcriptome analysis showed that 2691 differentially expressed genes (DEGs) were identified, including 1809 upregulated and 882 downregulated. Functional annotations revealed that the DEGs were mainly related to heat shock proteins (HSPs), ROS-scavenging enzymes, calcium-dependent protein kinases (CDPK), HSP-HSP network, hormone signaling transduction pathway, and transcription factors such as bHLHs, bZIPs, MYBs, WRKYs, and NACs. These heat-responsive candidate genes and TFs could significantly regulate heat stress tolerance in C. tangshen. Overall, this study could provide new insights for understanding the underlying molecular mechanisms of thermotolerance in C. tangshen. [ABSTRACT FROM AUTHOR]

Chromoplasts are specialized plastids in plants involved in carotenoid synthesis, accumulation, and stress resistance. In tomatoes (Solanum lycopersicum), the Chromoplast-associated carotenoid binding protein (CHRC) regulates chromoplast development and carotenoid accumulation, although its precise mechanisms are not yet fully understood. To investigate the role of SlCHRC in carotenoid biosynthesis, we generated transgenic tomatoes using overexpression (oe- SlCHRC) and CRISPR/Cas9-mediated gene editing (cr- SlCHRC) techniques. The results demonstrated inhibited fruit ripening and delayed onset of color break in both transgenic lines. The oe- SlCHRC lines exhibited increased carotenoid accumulation, particularly (E/Z)-phytoene, lycopene, and γ-carotene, with abundant plastoglobules and carotenoid crystals observed via TEM. In contrast, cr- SlCHRC mutants showed a greener phenotype, reduced carotenoid content, and fewer plastoglobules at the BK + 10 stage. Transcriptome analysis indicated that SlCHRC influences key genes in carotenoid biosynthesis, such as SlNCED2 , as well as genes related to chloroplast development, photosynthesis, and plastoglobule formation. Additionally, SlCHRC enhances heat stress tolerance in tomato fruits by upregulating heat shock proteins (HSPs), antioxidants, and proline accumulation. These findings indicate that SlCHRC plays a crucial role in improving tomato fruit quality under heat stress conditions. [Display omitted] • Overexpression of SlCHRC enhances carotenoid content, especially(E/Z)-phytoene, lycopene and γ-carotene. • CRISPR/Cas9-mediated knockout of SlCHRC results in delayed fruit ripening, reduced carotenoid content, and a greener fruit phenotype. • SlCHRC influences plastid ultrastructure and development, particularly plastoglobules. • SlCHRC modulates expression of genes involved in abscisic acid biosynthesis, chloroplast development, photosynthesis, and plastoglobule formation. • SlCHRC upregulates heat shock proteins (HSPs), antioxidants, and proline accumulation, enhancing heat stress tolerance in tomato fruits. [ABSTRACT FROM AUTHOR]

Rising temperatures and intensified agricultural practices have heightened heat stress (HS)-related challenges in poultry farming, notably heat-induced sudden death in chickens. Wenchang chickens, recognized for their heat resistance, have emerged as the potential candidates for improving the economic efficiency of poultry farming. The adrenal gland plays a crucial role in preventing HS-induced heart failure sudden death by secreting hormones. However, little is known about the damage to and resilience of Wenchang chicken adrenal glands during HS. In this study, 34 healthy Wenchang chickens with similar weights were selected for formal experimentation, with 10 as the control group (Con). Following a single exposure to acute HS of 42 ± 1°C and 65% relative humidity for 5 h, 15 deceased individuals formed the HS death (HSD) group, and 9 survived comprised the HS survival (HSS) group. ELISA revealed significant higher (P < 0.05) levels of COR and NE in the HSS and the lowest levels of CORT and EPI in the HSD. Histopathological analysis indicated major degeneration in HSS cortical and chromaffin cells and extensive cell necrosis (nuclear pyknosis) in HSD. Proteomic analysis identified 572 DEPs in HSD vs. Con and 191 DEPs in HSS vs. Con. Bioinformatics highlighted ER protein processing, especially ERAD as a key pathway for heat stress resistance (HSR) in the adrenal gland, with HSPH1, DNAJA1, HSP90AA1, HSPA8 and HERPUD1 identified as regulating key molecules. Western blotting validated significantly higher (P < 0.01) protein levels in both HSS and HSD compared to the Con. Immunohistochemical staining showed increased cytoplasmic HSPH1-positive signal intensity under HS and enhanced HSP90AA1 nuclear signals, strongest in HSS. In summary, HS induces pathological damage in Wenchang chicken adrenal glands, affecting hormone secretion, and various heat shock proteins play crucial roles in cellular resistance. These results elucidate the biological basis of HSR in Wenchang chickens from the perspective of the adrenal gland and provide necessary research foundations for enhancing economic performance of various broilers in high-heat environments and screening drugs for HS treatment. [ABSTRACT FROM AUTHOR]

Heat stress has been shown to have a detrimental impact on testicular activity and spermatogenesis. Ellagic acid is a plant-derived organic compound that has a variety of biological functions. Thus, it is believed that ellagic acid may improve heat-stressed testicular dysfunction. There has been no research on the impact of ellagic acid on heat-stressed testicular dysfunction. The mice were divided into 4 groups. The first group was the normal control group (CN), and the second received heat stress (HS) by submerging the lower body for 15 min in a water bath with a thermostatically controlled temperature kept at 43°C (HS), and the third and fourth groups were subjected to heat-stress similar to group two and given two different dosages of ellagic acid (5 mg/kg (EH5) and 50 mg/kg (EH50) for 14 days. Ellagic acid at a dose of 50 mg/kg improved the level of circulating testosterone (increased 3βHSD) and decreases the oxidative stress. The testicular and epididymal architecture along with sperm parameters also showed improvement. Ellagic acid treatment significantly increases the germ cell proliferation (GCNA, BrdU staining) and Bcl2 expression and decreases active caspase 3 expression. Heat stress downregulated the expression of AR, ER-α and ER-β, and treatment with ellagic acid increased the expression of ER-α and ER-β markers in the 50 mg/kg treatment group. Thus, our finding suggests that ellagic acid ameliorates heat-induced testicular impairment through modulating testosterone synthesis, germ cell proliferation, and oxidative stress. These effects could be manifested by regulating androgen and estrogen receptors. However, the two doses showed differential effects of some parameters, which require further investigation. • Ellagic acids improved testicular structures and sperm concentration in heat-stressed mice. • Testicular germ cell proliferation also increased by the ellagic acids. • Ellagic acids treatment suppresses heat-stressed induced apoptosis in the testis. • Ellagic acids mediated mitigation of testicular activity may be via regulating androgen and estrogen receptors. [ABSTRACT FROM AUTHOR]

Evaluation of the effects of feeding NutraGen supplement (NutraGen, NTG; Phibro Animal Health, Teaneck, NJ, USA) on growth performance, energetic efficiency, carcass characteristcs, and characteristics of digestion in calf-fed Holstein steers fed a conventional growing-finishing diet. Trial 1 evaluated growth performance, dietary energetics and carcass characteristics. Two hundred Holstein steer calves (134 ± 5 kg) were blocked by initial body weight (BW) and randomly assigned to 40 pens (5 steers/pen). Dietary treatments consisted of a steam-flaked corn-based growing-finishing diet supplemented with 0, 0.2, 0.4, or 0.6% NTG (DM basis). In trial 2, four Holstein steers (170 ±6 kg) with cannulas in the rumen and proximal duodenum were used in a 4 × 4 Latin square experiment to evaluate digestibility and ruminal characteristics using the treatments from trial 1. Compared to non-supplemented cattle, NTG increased BW (2.0%, P = 0.02) and tended to increase ADG (3.6%, P = 0.07) during the initial 56 d period. However, there were no treatment effects on overall growth performance and efficiency of dietary energy utilization after the first 56 days (P > 0.10). Supplementation of NTG increased (linear effect; P ≤ 0.03) longissimus muscle area and kidney, pelvic, and heart fat. There was no effect (P ≥ 0.05) of NTG supplementation on other carcass characteristics, liver abscess incidence, or liver abscess scars. Supplementation decreased the molar proportion of ruminal propionate (P = 0.05) and tended to increase acetate:propionate molar ratio (P = 0.09). However, there was no effect of NTG supplementation on ruminal and total tract diet digestion. NTG increased performance of Holstein steers during the first 56 d on feed in the feedlot. In addition, the steers had an increase in KPH fat and LM area, indicating that the additive induced change in metabolism of the steers.

Climate change adaptation decisions often require the consideration of risk rather than the environmental hazard alone. One approach for quantifying risk is to use a risk assessment framework which combines information about hazard, exposure and vulnerability to estimate risk in a spatially consistent way. In recent years, publicly available, open-source risk assessment frameworks have been made available, including the CLIMADA platform. Such tools are increasingly being used in combination with ensembles of climate model projections to quantify risk on climate time-scales, presenting the ensemble spread as a measure of climate model uncertainty. As climate models are computationally expensive to run, this quantification of uncertainty derived from the ensemble of projections is often limited by the number of members available. We present a novel framework involving the application and extension of the CLIMADA open-source climate risk assessment platform, demonstrating an approach for overcoming this limitation. We first show how the CLIMADA platform can be applied to an ensemble of UKCP18 regional climate projections to assess climate risk coherently across space in an idealised example for the UK. We then show how a Generalised Additive Model, involving an ‘ensemble member’ random effect term, can be used to statistically represent the climate model ensemble summary of risk and be used to simulate many more realisations of risk, representative of a larger collection of plausible ensemble members. Specifically, we apply the framework to an idealised example related to heat-stress and the associated risk of reduced outdoor physical working capacity in the UK, based on three global warming levels (recent past, 2 °C and 4 °C warmer than pre-industrial). We show how, in this idealised example, in a 2 °C warmer world (relative to pre-industrial), the UK could lose on average 15 million (or 2.5% of) days of outdoor physical work in a working year (225 days) as a result of heat-stress, which could equate to more than £1.5 billion of economic loss (roughly 0.07% of UK annual GDP). The uncertainty quantification provided by the framework allows for an upper range estimate which better quantifies climate model uncertainty. In a 4 °C warmer world this indicates the plausibility of38 million (or 6.2% of) working days lost in a year, possibly equating to more than £3.8 billion of economic loss (roughly 0.17% of UK annual GDP). Finally, we discuss limitations of the approach and recommend a number of extensions and areas of future work.

Insulin plays important role in testicular functions such as germ cell proliferation and steroidogenesis, despite its conventional role as a hypoglycaemic agent. It is also well known that testicular activity is severely get affected by heat stress and heat stress induces testicular pathogenesis. The effect of insulin on heat‐induced testicular impairment has not been investigated. Thus, it is hypothesized that insulin might modulate testicular activity in a heat‐stressed model. Experimental mice were separated into 4 groups; the first group was the normal control (CN), and the second group was subjected to heat stress (HS) by submerging the lower body part in a thermostatically controlled water bath maintained at 43°C for 15 min. The third and fourth groups were treated with a single dose of intra‐testicular insulin (0.6 IU/mice) before and after heat stress. Animal tissue samples were collected after 14 days of heat treatment. Insulin treatment did not improve the sperm parameters; however, both insulin pre and post‐treatment improved the markers of spermatogenesis such as Johnsen score, germinal epithelium height and the number of stages VII/VIII. The histoarchitecture of testis also showed amelioration from heat‐induced pathogenesis in the insulin‐treated groups. Insulin treatment has also increased the proliferation of germ cells (increased PCNA and GCN), survival (Bcl2), and decreased apoptosis (active caspase‐3). Furthermore, insulin treatment decreased MDA levels, without pronounced effects on the activities of antioxidant enzymes. Heat stress also decreased the circulating testosterone and oestrogen levels, and insulin treatment significantly increased oestrogen levels only. Although testosterone showed an increasing trend, it was insignificant. The expression of aromatase, AR, ER‐α, and ER‐β was down regulated by heat‐stress and insulin treatment up regulated these markers. In conclusion, our results showed the amelioration of heat‐induced testicular impairment by pre and post‐intra‐testicular insulin treatments. Insulin‐associated improvements in the pre‐and post‐treatment groups suggested a preventive mechanism of insulin against heat stress in the testis. [ABSTRACT FROM AUTHOR]

The article focuses on the Centers for Disease Control and Prevention Environmental Public Health Tracking Program which is the Environmental Public Health Tracking Network examines as a web-based system with components at the local, state, and national levels. Topics include examines the Tracking Network brings together standardized data on environmental hazards, exposures to these hazards, potentially related health effects, and other data such as socioeconomic.

Toxin-antitoxin (TA) systems are important for stress adaptation in prokaryotes, including persistence, antibiotic resistance, pathogenicity, and biofilm formation. Toxins can cause cell death, reversible growth stasis, and direct inhibition of crucial cellular processes through various mechanisms, while antitoxins neutralize the effects of toxins. In bacteria, these systems have been studied in detail, whereas their function in archaea remains elusive. During heat stress, the thermoacidophilic archaeon Sulfolobus acidocaldarius exhibited an increase in the expression of several bicistronic type II vapBC TA systems, with the highest expression observed in the vapBC4 system. In the current study, we performed a comprehensive biochemical characterization of the VapBC4 TA system, establishing it as a bonafide type II toxin-antitoxin system. The VapC4 toxin is shown to have high-temperature catalyzed RNase activity specific for mRNA and rRNA, while the VapB4 antitoxin inhibits the toxic activity of VapC4 by interacting with it. VapC4 toxin expression led to heat-induced persister-like cell formation, allowing the cell to cope with the stress. Furthermore, this study explored the impact of vapBC4 deletion on biofilm formation, whereby deletion of vapC4 led to increased biofilm formation, suggesting its role in regulating biofilm formation. Thus, during heat stress, the liberated VapC4 toxin in cells could potentially signal a preference for persister cell formation over biofilm growth. Thus, our findings shed light on the diverse roles of the VapC4 toxin in inhibiting translation, inducing persister cell formation, and regulating biofilm formation in S. acidocaldarius , enhancing our understanding of TA systems in archaea., Importance: This research enhances our knowledge of toxin-antitoxin (TA) systems in archaea, specifically in the thermoacidophilic archaeon Sulfolobus acidocaldarius . TA systems are widespread in both bacterial and archaeal genomes, indicating their evolutionary importance. However, their exact functions in archaeal cellular physiology are still not well understood. This study sheds light on the complex roles of TA systems and their critical involvement in archaeal stress adaptation, including persistence and biofilm formation. By focusing on S. acidocaldarius , which lives in habitats with fluctuating temperatures that can reach up to 90°C, the study reveals the unique challenges and survival mechanisms of this organism. The detailed biochemical analysis of the VapBC4 TA system, and its crucial role during heat stress, provides insights into how extremophiles can survive in harsh conditions. The findings of this study show the various functions of the VapC4 toxin, including inhibiting translation, inducing persister-like cell formation, and regulating biofilm formation. This knowledge improves our understanding of TA systems in thermoacidophiles and has broader implications for understanding how microorganisms adapt to extreme environments.

Egg quality is of economic consideration especially in thermally challenged confinements during table egg production and transportation. The effect of vitamin-C and folate on heat-stressed chickens' egg quality and performance is aimed at overcoming the negative impact of exposure to increased environmental heat load at peak heat periods of the year using vitamin-C as ameliorative agent, and efficient utilization of consumed feed, using folate. This is in other to lay quality eggs and perform optimally. A total of 72 Isa Brown laying hens at 31 weeks of age were randomly divided into 4 treatment groups of 36 birds subdivided into 3 replicates and indicated as T1, T2, T3 and T4 while T1 served as the control treatment. The birds were housed in a deep litter pen and exposed to 3-hours additional heat generated with gas-powered burners, for four consecutive days of each week for a period of 12 weeks. The diets for T2, T3 and T4 were supplemented with 250 mg of vitamin-C, 250 mg of vitamin-C + 1 mg of folate and 300 mg of vitamin-C + 1 mg of folate per kg of feed respectively. The results showed that T4 had the highest egg weights (60.04 g), shell thickness (0.53 mm) and shell weights (7.80 g). The albumin weight (37.20 g), albumin height (6.80 mm) and yolk weight (14.70 g) were highest (P<0.05) in T4 while daily eggs production/treatment/day was highest in T4 (8.04). The daily feed intake was (P<0.05) highest in T3 and T4 (0.42 kg/bird) and (P<0.05) lowest in T3 and T4 (1.51). It is concluded that combined supplementation of layers' diet with vitamin-C and folate at the ratio of 350 mg: 1 mg/kg of feed) help to reduce negative impact of heat stress and enhance efficient utilization of feed consumed. It is recommended as a nutritional management strategy in minimizing the negative impact of increased heat load coupled with very high relative humidity. [ABSTRACT FROM AUTHOR]

As the Earth’s temperature continues to increase, the livestock industry faces a growing challenge related to heat stress. Heat stress significantly impacts the global dairy and beef industries, affecting milk and meat production, reproductive health, and the general welfare of animals. This presentation will showcase how early-life exposure to heat stress in cattle, specifically during the prenatal (in utero) and postnatal (pre-weaning) phases of the life of a calf, can program them for a lifetime. Our studies have aimed to understand the physiological and behavioral changes that early-life heat stress induces and the molecular mechanisms underlying long-term programming effects on growth, survival, and lifetime performance. Using a multifaceted approach, we have investigated the transcriptomic, epigenetic, and metabolic responses of calves exposed to heat stress or provided with heat abatement during critical developmental periods. Our studies shed light on how early-life exposure to heat stress alters the developmental trajectory of cattle, potentially influencing their resilience to future environmental challenges and overall productivity. Strategies for mitigating heat stress in beef cow-calf pairs and pregnant dairy cows (e.g., pasture artificial shade and evaporative cooling, respectively) will be discussed. These research insights will aid in developing targeted management strategies and breeding programs to reduce the adverse programming effects of heat stress in cattle, ensuring the sustainability and resilience of livestock production systems in the face of climate change. [ABSTRACT FROM AUTHOR]

Exposure to high ambient temperature is a stressor that influences both biological and behavioral functions and has been previously shown to have an extensive impact on brain structure and function. Physiological, cellular and behavioral responses to heat-stress (HS) (40–41 °C, 2 h) were evaluated in adult male Sprague-Dawley rats. The effect of HS exposure before predator-scent stress (PSS) exposure (i.e., HS preconditioning) was examined. Finally, a possible mechanism of HS-preconditioning to PSS was investigated. Immunohistochemical analyses of chosen cellular markers were performed in the hippocampus and in the hypothalamic paraventricular nucleus (PVN). Plasma corticosterone levels were evaluated, and the behavioral assessment included the elevated plus-maze (EPM) and the acoustic startle response (ASR) paradigms. Endogenous levels of heat shock protein (HSP)-70 were manipulated using an amino acid (L-glutamine) and a pharmacological agent (Doxazosin). A single exposure to an acute HS resulted in decreased body mass (BM), increased body temperature and increased corticosterone levels. Additionally, extensive cellular, but not behavioral changes were noted. HS-preconditioning provided behavioral resiliency to anxiety-like behavior associated with PSS, possibly through the induction of HSP-70. Targeting of HSP-70 is an attractive strategy for stress-related psychopathology treatment. [ABSTRACT FROM AUTHOR]

Heat stress represents a real menace of the poultry industry all around the world. The World Meteorological Organization (WMO) predicts an increasing temperature by 1.5°C as early as 2024. The normal body temperature of a chicken is about 41°C, and its thermoneutral comfort zone ranges between 18-25°C. To avoid the overheating and to dissipate the excess heat the poultry's body conducts a demanding struggle, therefore it affects production and immune parameters, and also eggs' quality. Reduced appetite and feed intake due to an impaired digestion and metabolism caused by intestinal morphology damage requires different strategies against the negative impacts of heat stress. Dietary herbal supplementation with natural and inexpensive ingredients can be considered an efficient strategy. There are globally available, with scientific demonstrated thermoregulatory effects, and also with antioxidant properties that enhances the production parameters and the health status of poultry. Herbal utilization offers medium and long-term economic and natural potential to minimize the negative effects of heat stress in local and global poultry industry. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are non-coding small RNAs that play crucial roles in plant development and stress responses and can regulate plant interactions with beneficial soil microorganisms such as arbuscular mycorrhizal fungi (AMF). To determine if root inoculation with distinct AMF species affected miRNA expression in grapevines subjected to high temperatures, RNA-seq was conducted in leaves of grapevines inoculated with either Rhizoglomus irregulare or Funneliformis mosseae and exposed to a high-temperature treatment (HTT) of 40 °C for 4 h per day for one week. Our results showed that mycorrhizal inoculation resulted in a better plant physiological response to HTT. Amongst the 195 identified miRNAs, 83 were considered isomiRs, suggesting that isomiRs can be biologically functional in plants. The number of differentially expressed miRNAs between temperatures was higher in mycorrhizal (28) than in non-inoculated plants (17). Several miR396 family members, which target homeobox-leucine zipper proteins, were only upregulated by HTT in mycorrhizal plants. Predicted targets of HTT-induced miRNAs in mycorrhizal plants queried to STRING DB formed networks for Cox complex, and growth and stress-related transcription factors such as SQUAMOSA promoter-binding-like-proteins, homeobox-leucine zipper proteins and auxin receptors. A further cluster related to DNA polymerase was found in R. irregulare inoculated plants. The results presented herein provide new insights into miRNA regulation in mycorrhizal grapevines under heat stress and can be the basis for functional studies of plant-AMF-stress interactions.

Codonopsis tangshen Oliv (C. tangshen) is a valuable traditional Chinese medicinal herb with tremendous health benefits. However, the growth and development of C. tangshen are seriously affected by high temperatures. Therefore, understanding the molecular responses of C. tangshen to high-temperature stress is imperative to improve its thermotolerance. Here, RNA-Seq analysis was performed to investigate the genome-wide transcriptional changes in C. tangshen in response to short-term heat stress. Heat stress significantly damages membrane stability and chlorophyll biosynthesis in C. tangshen, as evidenced by pronounced malonaldehyde (MDA), electrolyte leakage (EL), and reduced chlorophyll content. Transcriptome analysis showed that 2691 differentially expressed genes (DEGs) were identified, including 1809 upregulated and 882 downregulated. Functional annotations revealed that the DEGs were mainly related to heat shock proteins (HSPs), ROS-scavenging enzymes, calcium-dependent protein kinases (CDPK), HSP-HSP network, hormone signaling transduction pathway, and transcription factors such as bHLHs, bZIPs, MYBs, WRKYs, and NACs. These heat-responsive candidate genes and TFs could significantly regulate heat stress tolerance in C. tangshen. Overall, this study could provide new insights for understanding the underlying molecular mechanisms of thermotolerance in C. tangshen.

Sound is an essential source of information in many taxa and can notably be used by embryos to programme their phenotypes for postnatal environments. While underlying mechanisms are mostly unknown, there is growing evidence for the involvement of mitochondria--main source of cellular energy (i.e. ATP)--in developmental programming processes. Here, we tested whether prenatal sound programmes mitochondrial metabolism. In the arid-adapted zebra finch, prenatal exposure to 'heat-calls'--produced by parents incubating at high temperatures--adaptively alters nestling growth in the heat. We measured red blood cell mitochondrial function, in nestlings exposed prenatally to heat- or control-calls, and reared in contrasting thermal environments. Exposure to high temperatures always reduced mitochondrial ATP production efficiency. However, as expected to reduce heat production, prenatal exposure to heat-calls improved mitochondrial efficiency under mild heat conditions. In addition, when exposed to an acute heat-challenge, LEAK respiration was higher in heat-call nestlings, and mitochondrial efficiency low across temperatures. Consistent with its role in reducing oxidative damage, LEAK under extreme heat was also higher in fast growing nestlings. Our study therefore provides the first demonstration of mitochondrial acoustic sensitivity, and brings us closer to understanding the underpinning of acoustic developmental programming and avian strategies for heat adaptation. [ABSTRACT FROM AUTHOR]

Purpose: Millions of workers exposed to the outdoor environment are extremely susceptible to extreme heat. Although several articles analyzed heat-related illnesses, injuries, fatalities at the country level, few investigated regional and state statistics especially for OSHA Region 4 and the state of Alabama, U.S, which we explored in this study. Methods: We studied the number of heat-days over 90 °F (32.2 °C) heat-index within our study area, analyzed heat-related injury and illnesses to calculate their incidence rate during 2015 to 2019, observed the nature of such incidents, their monthly occurrence, and incidence trend over average air temperature. We conducted a comparative analysis of heat-related fatalities between construction and all industries. The existing heat regulations by OSHA and some state agencies have also been summarized. Results: We observed the highest mean, maximum heat-days and injury-illness rate in the south and southeast part of Region 4; increase in incidence rate from 0.03 in 2017 to 0.28 per 10,000 employees in 2018 for the contiguous U.S; highest injury-illness rate (HIR) in OSHA Region 1, 4 and 6; highest HIR in Lee, Montgomery, Mobile and Madison counties of Alabama; 34.7% (construction) and 31.3% (all industries) of all cases experiencing nonclassifiable heat-light effects; high fatalities in construction industry with a trend of 1 death/5 years; increased mortality in all occupations with 1 death/2.4 years. We also proposed a Heat-Stress Index (HSI) as a routine heat-stress measure on jobsite. Conclusion: The findings from this research and the proposed index can help in understanding heat-related risk at a regional level and implementing workplace interventions. [ABSTRACT FROM AUTHOR]

Heat stress disturbs the mutualistic relationship between the hard corals and the symbiotic algae, which cause coral bleaching. A wide array of biochemical parameters is used to demonstrate the phenomenon. This study exposed a shallow-water hard coral, Acropora digitifera, to a series of elevated temperatures over time while the interaction between Symbiodiniaceae (SD) density, antioxidants activities, fatty acid (FA) composition, and putative FA health indicators was evaluated. Heat stress caused a substantial loss in SD densities, consequently regulated the antioxidant activities and caused significant changes in FA composition. There was a lack of evidence showing A. digitifera experienced oxidative stress; nonetheless, a significant decrease of monounsaturated fatty acid as (MUFA) and polyunsaturated fatty acid (PUFA) during the thermally induced experiment demonstrated that corals utilize their unsaturated FA as a final barrier or as a repair system against oxidative damage once the antioxidant enzyme cannot cope with stress condition. The lower ratio of putative FA health indicators [i.e., n-3 LC:n-6 LC, eicosapentaenoic acid (EPA):arachidonic acid (ARA), and docosahexaenoic acid (DHA):ARA] characterized an unhealthy coral. The loss of SD density was significantly correlated with certain PUFA markers [i.e., linolenic acid (18:3n6), 20:5n3, and 22:6n3] and putative FA health indicator (i.e., n-3 LC:n-6 LC, EPA:ARA, and DHA:ARA). These notably imply that the FA linked with the symbiont can be a potential health indicator for assessing the effect of the environmental stressor on coral. This study also revealed the regulation of FAs during stress conditions, especially when heterotrophic feeding is limited. Future studies on FA profiles toward antagonistic or synergistic effects will offer a better understanding of the nature of this relationship under a harsh climate.

A primary selection target for wheat (Triticum aestivum) improvement is grain yield. However, the selection for yield is limited by the extent of field trials, fluctuating environments, and the time needed to obtain multiyear assessments. Secondary traits such as spectral reflectance and canopy temperature (CT), which can be rapidly measured many times throughout the growing season, are frequently correlated with grain yield and could be used for indirect selection in large populations particularly in earlier generations in the breeding cycle prior to replicated yield testing. While proximal sensing data collection is increasingly implemented with high-throughput platforms that provide powerful and affordable information, efficient and effective use of these data is challenging. The objective of this study was to monitor wheat growth and predict grain yield in wheat breeding trials using high-density proximal sensing measurements under extreme terminal heat stress that is common in Bangladesh. Over five growing seasons, we analyzed normalized difference vegetation index (NDVI) and CT measurements collected in elite breeding lines from the International Maize and Wheat Improvement Center at the Regional Agricultural Research Station, Jamalpur, Bangladesh. We explored several variable reduction and regularization techniques followed by using the combined secondary traits to predict grain yield. Across years, grain yield heritability ranged from 0.30 to 0.72, with variable secondary trait heritability (0.0–0.6), while the correlation between grain yield and secondary traits ranged from −0.5 to 0.5. The prediction accuracy was calculated by a cross-fold validation approach as the correlation between observed and predicted grain yield using univariate and multivariate models. We found that the multivariate models resulted in higher prediction accuracies for grain yield than the univariate models. Stepwise regression performed equal to, or better than, other models in predicting grain yield. When incorporating all secondary traits into the models, we obtained high prediction accuracies (0.58–0.68) across the five growing seasons. Our results show that the optimized phenotypic prediction models can leverage secondary traits to deliver accurate predictions of wheat grain yield, allowing breeding programs to make more robust and rapid selections.

A primary selection target for wheat (Triticum aestivum) improvement is grain yield. However, the selection for yield is limited by the extent of field trials, fluctuating environments, and the time needed to obtain multiyear assessments. Secondary traits such as spectral reflectance and canopy temperature (CT), which can be rapidly measured many times throughout the growing season, are frequently correlated with grain yield and could be used for indirect selection in large populations particularly in earlier generations in the breeding cycle prior to replicated yield testing. While proximal sensing data collection is increasingly implemented with high-throughput platforms that provide powerful and affordable information, efficient and effective use of these data is challenging. The objective of this study was to monitor wheat growth and predict grain yield in wheat breeding trials using high-density proximal sensing measurements under extreme terminal heat stress that is common in Bangladesh. Over five growing seasons, we analyzed normalized difference vegetation index (NDVI) and CT measurements collected in elite breeding lines from the International Maize and Wheat Improvement Center at the Regional Agricultural Research Station, Jamalpur, Bangladesh. We explored several variable reduction and regularization techniques followed by using the combined secondary traits to predict grain yield. Across years, grain yield heritability ranged from 0.30 to 0.72, with variable secondary trait heritability (0.0–0.6), while the correlation between grain yield and secondary traits ranged from −0.5 to 0.5. The prediction accuracy was calculated by a cross-fold validation approach as the correlation between observed and predicted grain yield using univariate and multivariate models. We found that the multivariate models resulted in higher prediction accuracies for grain yield than the univariate models. Stepwise regression performed equal to, or better than, other models in predicting grain yield. When incorporating all secondary traits into the models, we obtained high prediction accuracies (0.58–0.68) across the five growing seasons. Our results show that the optimized phenotypic prediction models can leverage secondary traits to deliver accurate predictions of wheat grain yield, allowing breeding programs to make more robust and rapid selections. [ABSTRACT FROM AUTHOR]

The adipokines, visfatin, chemerin, and its receptor are expressed in the testis. It has also been shown that heat-stress alters the secretion and expression of other adipokines. Testicular heat-stress is now well known to cause the impairment in the testis. It has also been documented that heat-stress changes the expression of genes and proteins in the testis. To the best of our knowledge, the expression and localization of visfatin chemerin and its receptor have not been investigated in the heat-stressed testis. Therefore, the present study has investigated the expression and localization of these proteins in the heat-stressed testis. The expression of visfatin and chemerin and receptor exhibits a differential repossess against the heat stress. Visfatin expression was up-regulated while chemerin and chemerin receptor was down-regulated in the heat-stressed testis as shown by western blot analysis. The immunolocalization of visfatin and chemerin showed increased abundance in the seminiferous tubules of heat-stressed mice testis. Furthermore, abundance of visfatin, chemerin, and its receptor showed a decrease in abundance in the Leydig cells of heat-stressed testis. The decreased abundance of these proteins in the Leydig cells coincides with decreased 3β-HSD immunostaining along with decreased testosterone levels. These results suggest that heat-stress might decrease testosterone secretion by modulating visfatin and chemerin in the Leydig cells. The increased abundance of visfatin and chemerin in the primary spermatocytes, round spermatid, and multinucleated germ cells also coincides with increased immunostaining of active caspase-3. Moreover, expression of Bcl-2 was down-regulated, and expression of active caspase-3 and HSP70 were up-regulated along with increased oxidative stress in the heat-stressed testis, suggesting stimulated apoptosis. In conclusion, our results showed that visfatin, chemerin, and its receptor are differentially expressed in the testis under heat-stress and within the testis also it might differentially regulate testosterone biosynthesis in the Leydig cells and apoptosis in the seminiferous tubules. • Heat-stress up-regulates visfatin and down-regulates chemerin and its receptor (CMKLR1) in the testis. • However, abundance of visfatin, chemerin and CMKLR1 decreases in the Leydig cells of heat-stressed testis. • The decreased abundance of visfatin and chemerin in Leydig cells coincides with decreased testosterone. • Elevated immunostaining of visfatin and chemerin in the seminiferous tubules coincides with increased apoptosis. • Heat-stressed differentially regulates the expression of visfatin and chemerin system. [ABSTRACT FROM AUTHOR]

Micro-plastics are emerging pollutants with a cosmopolitan distribution, and they are also well-known for their negative impacts on the terrestrial system. However, the effects of climate change factors such as - temperature and salinity stress on micro-plastics accumulation by plant roots and their toxicological behaviour in plants are unknown. In the present study, we deciphered how microplastics accumulation in onion roots changes under heat and salinity stress, affecting microtubules stability, organization, and water uptake by aquaporins. The fluorescence signal of nile-red stained micro-plastics in roots was detected with a marked reduction in the presence of aquaporins inhibitor – NaN3, showing the possible role of aquaporins in micro-plastics accumulation. It was further confirmed by changes in aquaporins genes expression. The acetylation of tubulin is an important post-translational modification that contributes to the stability of microtubule filaments. Micro-polystyrene effects on microtubules stability and organization were further aggravated by heat, but not salinity stress in accordance with ROS-level and antioxidant activity, indicating alarming risks of micro-plastics to the agro-ecosystem with global temperature rise. [Display omitted] • Aquaporins regulate micro-plastics accumulation in roots. • Micro-plastics affect microtubules stability and organization. • Heat stress accelerates micro-plastics internalization by increasing aquaporin expression. • Micro-plastics effect is more severe under heat stress than salinity stress. • Reduction in acetylated-α-tubulins depicts combined effects of micro-plastics and heat stress. [ABSTRACT FROM AUTHOR]

BackgroundHeat-induced browning (Hbs) of seed coats is caused by high temperatures which discolors the seed coats of many legumes, affecting the visual appearance and quality of seeds. The genetic determinants underlying Hbs in cowpea are unknown.ResultsWe identified three QTL associated with the heat-induced browning of seed coats trait, Hbs-1, Hbs-2 and Hbs-3, using cowpea RIL populations IT93K-503-1 (Hbs positive) x CB46 (hbs negative) and IT84S-2246 (Hbs positive) x TVu14676 (hbs negative). Hbs-1 was identified in both populations, accounting for 28.3% -77.3% of the phenotypic variation. SNP markers 1_0032 and 1_1128 co-segregated with the trait. Within the syntenic regions of Hbs-1 in soybean, Medicago and common bean, several ethylene forming enzymes, ethylene responsive element binding factors and an ACC oxidase 2 were observed. Hbs-1 was identified in a BAC clone in contig 217 of the cowpea physical map, where ethylene forming enzymes were present. Hbs-2 was identified in the IT93K-503-1 x CB46 population and accounted for of 9.5 to 12.3% of the phenotypic variance. Hbs-3 was identified in the IT84S-2246 x TVu14676 population and accounted for 6.2 to 6.8% of the phenotypic variance. SNP marker 1_0640 co-segregated with the heat-induced browning phenotype. Hbs-3 was positioned on BAC clones in contig512 of the cowpea physical map, where several ACC synthase 1 genes were present.ConclusionThe identification of loci determining heat-induced browning of seed coats and co-segregating molecular markers will enable transfer of hbs alleles into cowpea varieties, contributing to higher quality seeds.