Suboptimal Temperatures Research Articles

The Application of 1-MCP in Combination with GABA Reduces Chilling Injury and Extends the Shelf Life in Tomato (Cv. Conquista)

Tomatoes have a short shelf life, and refrigeration is commonly used to extend tomato quality. However, suboptimal temperatures can lead to chilling injury (CI), reducing their marketability. In this study, the combined application of 10 mM γ-aminobutyric acid (GABA) and 0.5 µL L−1 of 1-methylcyclopropene (1-MCP) were used as strategies to reduce postharvest CI and prolong storability during tomato commercialization. Both treatments have individually demonstrated their effectiveness in lowering physiological disorders in tomatoes. When applied, the combined treatment resulted in the lowest CI and rot incidence levels compared with the control and individual treatments. Additionally, the combined application effectively delayed weight loss, fruit softening, respiration rate, ethylene production, and increased chlorophyll and flavonoid content. The synergistic application of these substances improved the postharvest quality during storage, reducing quality losses. For this reason, the combination of GABA and 1-MCP could be an effective tool to minimize tomato waste during commercialization by increasing resilience to cold storage and extending the overall fruit shelf life during refrigerated storage.

Abstract 4118671: Extreme ambient temperatures increase the risk of congenital heart disease mortality: insights from the national mortality surveillance system of China

Background: Climate change is intricately linked to human health, and the cardiovascular system is particularly susceptible to suboptimal temperatures, causing premature mortality. Extensive research has confirmed a robust link between non-optimal temperatures and most cardiovascular diseases; however, limited focus has been given to investigating the association between non-optimal temperatures and mortality related to congenital heart disease (CHD), one of the most prevalent cardiovascular diseases among children. Research question: Do extreme temperatures increase the risk of CHD mortality? Aims: We aimed to investigate the association between CHD mortality and ambient temperatures. Methods: Based on the national mortality surveillance system of China, we applied a two stage, individual level, time-stratified case-crossover design to investigate the association between CHD mortality and ambient temperatures from 2013 to 2021, with different thresholds of events. After estimation within each province of China, we pooled all the estimations using meta-analytic method. Sensitivity analyses and subgroup analyses were used to explore the stability and vulnerable population. Results: From 2013 to 2021, a total of 32168 CHD deaths were recorded. Neonates and adults constituted the primary age groups among all CHD-related deaths, with a majority of patients being male (55.2%). Cold temperatures exhibited a significant association with the risk of CHD mortality, while no significant association was observed with heat temperatures (Figure 1). Cold extremes made a significant contribution to CHD mortality in most defined events, with the highest contribution observed in P5_5d (indicating temperatures below the 5th percentile lasting for 5 days; odd ratio [OR]: 1.15, 95% CI: 1.03 to 1.29) (Figure 2). In comparison to male patients, female patients appeared to be more vulnerable to cold extremes, with ORs ranging from 1.08 (95% CI: 1.01 to 1.16) for P10_1d to 1.20 (95% CI: 1.01 to 1.43) for P5_5d. Conclusion: Extreme cold temperatures significantly increase the risk of CHD mortality. This is the first study performed to explore the relationship between ambient temperatures and CHD mortality, and it may suggest policy-adjustment in healthcare of CHD population.

Impact of low temperature on bacterial community dynamics and process efficiency in anaerobic ammonia removal: A network analysis of metagenomic data

The implementation of anaerobic ammonia removal has potential for reducing the operating costs in wastewater treatment plants. However, the application of this process in mainstream treatment presents various challenges, particularly due to the sensitivity of anammox bacteria to low temperatures. To address these challenges, changes in the bacterial community were investigated under decreasing temperatures (from 30 to 12 °C) within a deammonification process conducted in a 10-L sequencing batch reactor (SBR) over a period of 114 days. The aim of the study was to determine which groups of microorganisms are most strongly linked by ecological relationships with anammox bacteria and how these relationships change in response to decreasing temperature. Community dynamics were analyzed by combining metagenomics, network analysis, and specific process rates. The nitrification process was most efficient at 25 °C, as indicated by high values of the ammonia and nitrite utilization rate, and nitrate production rate, all of which declined as the temperature decreased. In contrast, the activity and abundance of anammox bacteria remained stable throughout all phases of the experiment. The decreasing temperature negatively impacted Nitrospira bacteria, the main competitors of anammox in the deammonification system. Despite the reduced process efficiency, the SBR maintained stable functionality even at temperatures as low as 12 °C. Network analysis identified which bacterial groups most frequently co-occurred and interacted, as well as those most sensitive to temperature fluctuations. Among the bacterial nodes, Nitrospira, Phycisphaerae, and Prosthecobacter exhibited the highest degree of connectivity, suggesting that they participate in multiple interactions, such as metabolite exchange, cooperation, or competition. Nevertheless, the temperature node had a greater number of connections than any bacterial node, indicating that this environmental factor had a more important effect on microbial community formation than direct ecological relationships. These results contribute to a comprehensive understanding of the role of anammox bacteria in deammonification systems, their ecological interactions within microbial networks, and their activity under suboptimal temperature conditions, which is crucial for future practical applications.

Kinetics of viral hemorrhagic septicemia virus (VHSV) and immune response in olive flounder (Paralichthys olivaceus) at altered temperature

Viral hemorrhagic septicemia virus (VHSV) is a pathogen that causes hemorrhagic septicemia in olive flounder at water temperatures below 15 °C, leading to symptoms such as abdominal swelling due to ascites and muscle hemorrhaging, and in severe cases, mortality. In this study, we investigated the proliferation of NCCs, the transcriptional analysis of CD4 and CD8, and the expression of pro-inflammatory cytokines (IL-1β, IL6, TNFα) and the cytokines (IL12, IL15, IFN-1β, IFNγ) involved in cytotoxic cell activation in the kidney of olive flounder during VHSV infection at suboptimal temperature (17 °C) and following a shift to optimal temperature (10 °C). Following viral infection, the population of NCCs and CD8 gene expression steadily increased. Meanwhile, IL12, IL15, and IFN-1β levels exhibited an early surge, reaching their peak within 1–2 days post-challenge at 17 °C. Notably, in olive flounder that were re-challenged with VHSV at 10 °C after an initial challenge at 17 °C, there was a rapid and robust expansion of NCCs and increased CD4 and CD8 gene expression, demonstrating the mounting of immune memory by NCCs and an efficient adaptive immune response from CD4+ and CD8+ T cells against VHSV infection.

Variability of plant transcriptomic responses under stress acclimation: a review from high throughput studies.

Plant transcriptomes are complex entities shaped spatially and temporally by a multitude of stressors. The aim of this review was to summarize the most relevant transcriptomic responses to selected abiotic (UV radiation, chemical compounds, drought, suboptimal temperature) and biotic (bacteria, fungi, viruses, viroids) stress conditions in a variety of plant species, including model species, crops, and medicinal plants. Selected basic and applicative studies employing RNA-seq from various sequencing platforms and single-cell RNA-seq were involved. The transcriptomic responsiveness of various plant species and the diversity of affected gene families were discussed. Under stress acclimation, plant transcriptomes respond particularly dynamically. Stress response involved both distinct, but also similar gene families, depending on the species, tissue, and the quality and dosage of the stressor. We also noted the over-representation of transcriptomic data for some plant organs. Studies on plant transcriptomes allow for a better understanding of response strategies to environmental conditions. Functional analyses reveal the multitude of stress-affected genes as well as acclimatory mechanisms and suggest metabolome diversity, particularly among medicinal species. Extensive characterization of transcriptomic responses to stress would result in the development of new cultivars that would cope with stress more efficiently. These actions would include modern methodological tools, including advanced genetic engineering, as well as gene editing, especially for the expression of selected stress proteins in planta and for metabolic modifications that allow more efficient synthesis of secondary metabolites.

The Germination Performance After Dormancy Breaking of Leucaena diversifolia (Schltdl.) Benth. Seeds in a Thermal Gradient and Its Distribution Under Climate Change Scenarios.

Climate change models predict temperature increases, which may affect germination, an important stage in the recruitment of individuals in agroecosystems. Therefore, it is crucial to conduct research on how temperature will impact the germination of multipurpose native species. Leucaena diversifolia (Schltdl.) Benth. is native to America and is commonly cultivated around the world due to having a high protein content in seeds, and their trees are used in agrosilvopastoral systems because they fix nitrogen and provide shade and cattle feed. However, climate change affects the critical phases of its life cycle and influences its growth, reproduction, phenology, and distribution. To assess the germination performance of Leucaena diversifolia under different temperatures throughout thermal times, we estimated germination variables and determined cardinal temperatures and thermal time; we also analysed germination and potential distribution under two climate change scenarios. We found significant variations in seed germination (78-98%) and differences in cardinal temperatures (Tb = 5.17 and 7.6 °C, To = 29.42 and 29.54 °C, and Tc = 39.45 and 39.76 °C). On the other hand, the sub-optimal and supra-optimal temperature values showed little differences: 51.34 and 55.57 °Cd. The models used showed variations in germination time for the analysed scenarios and the potential distribution. We confirm that the populations and distribution of L. diversifolia will be altered due to climate changes, but the species retains the ability to germinate under warmer conditions.

Role of total polyphenol content in seed germination characteristics of spring barley varieties amidst climate change

The amount of total polyphenol content (TPC) in the grain could provide insights into the conditions during maturation and might also serve as an indicator of the grain’s ability to germinate in the malting process or as seeds in the field. Varieties with higher natural TPC content might exhibit better germination parameters both in the field and in the malt house. This study investigates the relationship between TPC and seed germination characteristics i.e. seed vigour in four spring barley varieties over two years, considering diverse environmental conditions and exposure to drought conditions. The evaluation of seed germination characteristics in barley, with a focus on the root length and average diameter under drought conditions (−0.5 MPa) and suboptimal temperature (10 °C), was conducted. Drought conditions were induced using polyethylene glycol (PEG 6000). After durations of seven and fourteen days, the germinated seeds from the Petri dishes were scanned and subjected to analysis using WinRHIZO software following the metrics: Len 7, Len 14 (root length after seven and fourteen days in cm) and AvgD 7, AvgD 14 (root diameter after seven and fourteen days in mm). The findings support our initial hypothesis, indicating a variety-specific relationship between seed germination characteristics and increased TPC, where higher germination parameters might be associated with elevated TPC levels in some barley varieties.

Differential photosynthetic yield across a wide range of temperatures for Northern and invasive Watermilfoils

Eurasian watermilfoil (Myriophyllum spicatum) is one of the most challenging invasive aquatic plant species in Minnesota. Eurasian watermilfoil has hybridized with the native Northern watermilfoil (Myriophyllum sibiricum), creating a more complex issue when it comes to invasions. The hybridization of watermilfoil has increased difficulty for management and an underlying biological mechanism explaining this difficulty has yet to be determined. We compared the photosynthetic temperature response of the parental Northern and Eurasian parental genotypes to five hybrid watermilfoils using pulse amplitude modulated (PAM) chlorophyll fluorometry to determine if there are intrinsic physiological differences in photosynthesis between genotypes. We examined both the ratio of variable to maximal fluorescence (Fv/Fm) and light-adapted quantum yield of photosystem II (PSII) electron transfer (ΦPSII) every 5 °C from 0 to 45 °C representing sub- to supraoptimal water temperatures. On average, hybrids had 6% and 8% higher Fv/Fm and ΦPSII values respectively, than parental genotypes across all temperatures. In both parental and hybrid genotypes Fv/Fm values were consistent from 0 to 35 °C and declined 36% as water temperature approached 45 °C. Optimal water temperature for ΦPSII was between 25-35 °C and hybrids had 17% higher values for suboptimal temperatures between 5-15 °C. Our findings indicate that although the many strains of watermilfoil are morphologically similar, they differ in their photosynthetic capacity and may indicate heterosis. Innate differences between parental strains and hybrids could impact overall primary productivity, life history characteristics, and overall invasiveness. These factors could also be contributing to the documented management failures seen in field populations.

Contrasted agronomical and physiological responses of five Coffea arabica genotypes under soil water deficit in field conditions.

Breeding programs have developed high-yielding Coffea arabica F1-hybrids as an adaptation against adverse conditions associated with climate change. However, theresponse to drought of coffee F1 hybrids has seldom been assessed. A trial was established with five C. arabica genotypes (2 pure lines: Catimor and Marsellesa and 3 F1 hybrids: Starmaya, Centroamericano and Mundo Maya) planted under the leguminous tree species Leuceana leucocephala. Coffee growth, yield and physiological responses were assessed under a rain-fed (control: CON) and a rainfall reduction treatment (RR) for 2 years. The RR treatment created a long-term rainfall deficit in a region with suboptimal temperature similar to those predicted by climate change scenarios. Moreover, the RR treatment reduced soil water content by 14% over 2 successive years of production and increased hydric stress of the three F1-hybrids (leaf water potentials averaged -0.8 MPa under RR compared with -0.4 MPa under CON). Under RR, coffee yields were reduced from 16 to 75% compared to CON. Mundo Maya F1 hybrid was the sole high-yielding genotype apable of sustaining its yield under RR conditions. Our results suggested that its significant increase in fine root density (CON = 300 and RR = 910 root.m-2) and its maintenance of photosynthetic rate (2.5 - 3.5 mmol CO2 m-2 s-1) at high evaporative demand might explain why this genotype maintained high yield under RR condition. This work highlights a possible drought tolerance mechanism in fruit bearing adult coffee trees where the plant fine root number increases to intake more water in order to preserve turgor and sustainphotosynthesis at high ETo and therefore conserves high yield in dry conditions.

Effects of mandarin peel powder on growth, biochemical, immune, and intestinal health in Oreochromis niloticus at suboptimal temperatures

This 60-day study aimed to examine the efficacy of a diet supplemented with mandarin peel powder (MP) in enhancing the health and survival of Oreochromis niloticus under suboptimal temperature conditions (21 ℃). One hundred and eighty Nile tilapia fish (22.51 ± 0.04 g) were randomly distributed into four experimental groups; each of 3 replicates (15 fish per replicate). The first group (CONT) received a basal diet without MP. The second (MP10%), third (MP15%), and fourth (MP20%) groups were fed diets containing 10, 15, and 20% MP powder, respectively. At the end of the feeding trail, growth performance, serum growth hormone, α-amylase enzyme, lysozyme activity, nitric oxide, protease activity, globulin, serum levels of IL-1ß, antioxidant status, and intestinal histology were measured. The results showed insignificant differences between CONT, MP15%, and MP20% groups in the final body weight and specific growth rate. The growth hormones in the MP15% and MP20% groups did not show a significant difference compared to fish fed a normal basal diet (CONT). However, the amylase enzymes were significantly greater in both groups. The MP20% and MP15% groups showed a significant increase in antioxidant, lysozyme, nitric oxide, and protease activities compared to CONT. The results also showed that fish that were fed a diet with MP had significantly less of the pro-inflammatory cytokine interleukin-1 beta, and their intestinal villi got wider, especially in the MP20% group. It could be concluded that feeding tilapia on a diet with 20% MP is an effective strategy to improve their health when the temperature is below 21 °C. This is because the fish exhibit higher levels of antioxidant activity, reduced pro-inflammatory responses, and improved intestinal health without difference in the growth performance in compared to control group.

An approach to the prevention of global warming impact on human health

Global climate warming leads to an increase in eye, somatic and mental diseases, but the trigger of these processes is unknown, so treatment is ineffective. The author's hypothesis is that the trigger of health deterioration in global warming may be excessively constricted pupils, which trigger pathological biochemical processes in the body through the optic-vegetative system. It is proposed to moderately dilate the pupils of people who are sensitive to suboptimal temperatures in the course of a weather forecast of heat or cold, which will mitigate the course of their diseases and reduce mortality.

Comparison of transcriptome and metabolome analysis revealed cold-resistant metabolic pathways in cucumber roots under low-temperature stress in root zone.

Low ground temperature is a major factor limiting overwintering in cucumber cultivation facilities in northern alpine regions. Lower temperatures in the root zone directly affect the physiological function of the root system, which in turn affects the normal physiological activity of plants. However, the importance of the ground temperature in facilities has not attracted sufficient attention. Therefore, this study tested the cucumber variety Jinyou 35 under three root zone temperatures (room temperature, 20-22°C; suboptimal temperature, 13- 15°C; and low temperature, 8-10°C) to investigated possible cold resistance mechanisms in the root of cucumber seedlings through hormone, metabolomics, and transcriptomics analyses. The results showed that cucumber roots were subjected to chilling stress at different temperatures. Hormone analysis indicated that auxin content was highest in the roots. Jasmonic acid and strigolactone participated in the low-temperature stress response. Auxin and jasmonate are key hormones that regulate the response of cucumber roots to low temperatures. Phenolic acid was the most abundant metabolite in cucumber roots under chilling stress. Additionally, triterpenes may play an important role in chilling resistance. Differentially expressed genes and metabolites were significantly enriched in benzoxazinoid biosynthesis in the room temperature vs. suboptimal temperature groups and the room temperature vs. low temperature groups. Most differentially expressed transcription factor genes in AP2/ERF were strongly induced in cucumber roots by both suboptimal and low-temperature stress conditions. These results provide guidance for the cultivation of cucumber in facilities.

Increased production of orthoflavivirus single-round infectious particles produced in mammalian cells at a suboptimal culture temperature of 28°C

In the employment of serodiagnostic methods for the detection of orthoflavivirus infections, neutralization tests are known to be more accurate than measurements of antibody binding properties employing enzyme-linked immunosorbent assays. However, neutralization tests require infectious virus and laboratories with an appropriate level of biosafety. Single-round infectious particles (SRIPs), which encode a reporter gene instead of the viral structural protein genes, are replication incompetent and represent a safe and reliable alternative to the diagnosis of pathogenic viruses in neutralization tests. The orthoflavivirus SRIPs are produced by co-transfection of plasmids expressing virus-like particles and replicons into mammalian cell lines preferably with high transfection efficacy, such as HEK293T cells. However, certain orthoflavivirus SRIPs have limitations in their efficient expression at 37°C, which is the optimal temperature for mammalian cell growth, resulting in insufficient yields for neutralization tests. Here, we demonstrate that the production of orthoflavivirus SRIPs increases at the lower temperature of 28°C compared to 37°C. Moreover, infections with 28°C-cultured SRIPs in microneutralization tests were specifically inhibited in the presence of serum from mice infected with homologous viruses, suggesting that these SRIPs preserved their neutralizing epitopes for antibodies. Our method to produce high titer SRIPs is anticipated to promote efficient and safe SRIPs neutralization tests as a general serodiagnostic method for detecting virus-specific neutralizing antibodies against orthoflaviviruses.

Design and Implementation of a Biogas Pilot Plant for Bioaugmentation Strategies in a rural municipality

The transition towards renewable energy sources is imperative for achieving sustainability and mitigating climate change impacts. Among various renewable energies, biogas stands out for its dual role in waste management and energy production. This study introduces the design and implementation of a biogas pilot plant aimed at exploring bioaugmentation strategies to enhance biogas yield and quality. The pilot plant, located at Aras de los Olmos, features two independent 3.4m3 digesters, allowing for parallel comparison between standard anaerobic digestion and digestion with microbial enhancements. The plant is equipped with monitoring and control systems for precise regulation of environmental conditions, such as temperature, and for real-time measurement of biogas composition. Some initial experiments using a mix of agricultural wastes demonstrated the plant's capability to adapt to varied feedstock. Despite suboptimal temperature conditions, preliminary results indicated a high methane content, suggesting significant potential for bioaugmentation to improve biogas production efficiency. The study highlights the importance of controlled environmental conditions and introduces a novel bioaugmented digestion approach using selected microbial consortia. This research contributes to the broader goal of enhancing biogas technology's efficiency and sustainability, offering insights into the practical application of bioaugmentation in biogas production.

Assessing lethal and sublethal effects of pesticides on honey bees in a multifactorial context

The registration of novel pesticides that are subsequently banned because of their unexpected negative effects on non-target species can have a huge environmental impact. Therefore, the pre-emptive evaluation of the potential effects of new compounds is essential. To this aim both lethal and sublethal effects should be assessed in a realistic scenario including the other stressors that can interact with pesticides. However, laboratory studies addressing such interactive effects are rare, while standardized laboratory-based protocols focus on lethal effects and not on sub-lethal effects.We propose to assess both lethal and sublethal effects in a multifactorial context including the other stressors affecting the non-target species. We tested this approach by studying the impact on honey bees of the insecticide sulfoxaflor in combination with a common parasite, a sub-optimal temperature and food deprivation. We studied the survival and the transcriptome of honey bees, to assess both the lethal and the potential sublethal effects of the insecticide, respectively. With this method we show that a field realistic concentration of sulfoxaflor in food does not affect the survival of honey bees; however, the significant impact on some key genes indicates that sublethal effects are possible in a realistically complex scenario.Moreover, our results demonstrate the feasibility and reliability of a novel approach to hazard assessment considering the interactive effects of pesticides. We anticipate our approach to be a starting point for a paradigm shift in toxicology: from an unifactorial, mortality-centered assessment to a multifactorial, comprehensive approach. This is something of the utmost importance to preserve pollination, thus contributing to the sustainability of our food production system.

The effect of transport temperature and duration on survival and growth of house cricket nymphs and eggs

Abstract The transport of live insects is becoming increasingly common within the food and feed industry. However, very little information is available as to its effects on the insects themselves. The aim of this study was to monitor how variation in transport conditions, such as duration of transport and external temperature and humidity, directly and indirectly affect the survival and growth of nymphs of the house cricket, Acheta domesticus. In addition, we investigated the effect of external temperature on the viability of eggs upon completion of a transport event. We investigated how four different temperatures (5 °C, 15 °C, 25 °C, 35 °C) and four possible transport durations (1, 2, 3, 6 days) affected survival and growth of the cricket nymphs. To gain insight into the potential transport of eggs, its effect on egg hatch-rate was studied by storing eggs at three different temperatures (6 °C, 18 °C and 30 °C) before moving the eggs to optimal hatching conditions. We found that humidity remained constant inside the transport boxes and was different from the exterior humidity. Temperature had a significant effect on nymph survival and growth. The extreme temperatures negatively affected nymph survival, and increased temperature was correlated with increased growth. The development of eggs was also sensitive to temperature, and transport of eggs at suboptimal temperatures prolonged incubation time considerably. Finally, based on the results of this study, we discuss temperature optimisation as the most critical factor to consider during transport of live house cricket nymphs and eggs.

Evidence for seasonal shift in the reproduction of Aldabra giant tortoises (Aldabrachelys gigantea) in managed care in the Northern hemisphere compared to the natural habitat in the Southern hemisphere.

Ex situ breeding constitutes an important tool for species conservation; however, many reptile species are not managed sustainably under human care due to poor fecundity in ex situ settings. In this study, we tested whether the translocation of a seasonally reproducing species to a different environment results in decoupling of extrinsic signals and intrinsic conditions. The endocrinological patterns of plasma steroid sex hormones, follicular development, and mating behaviour of two female and two male sexually mature Aldabra tortoises (Aldabrachelys gigantea) in a zoological institution in the Northern hemisphere was aligned with enclosure climate data (mean monthly daylight duration, temperature, and precipitation) and compared with respective hormone patterns of wild individuals and climate conditions in the native habitat on the Aldabra Atoll in the Southern hemisphere. Whereas occurrence of mating behaviour was not considered a limiting factor, lack of ovulation and subsequent follicular atresia was the main reason for the lack of reproductive output. While it was impossible to elucidate the triggering factors of ovulation and the multifactorial complexity of reproduction was not fully addressed, this study indicates suboptimal temperature conditions and relative temporal shifts of interacting external triggers (temperature and photoperiod) in the zoo setting.

P-141 Elevating human oocyte vitrification and warming to a new level: fast, efficient, and effective

Abstract Study question Due to the rising trend for oocyte cryopreservation and increasing demand, there is an urgency to make oocyte vitrification and warming protocols more efficient. Summary answer Oocyte vitrification and warming can be done successfully in 4 minutes, reducing the time of commonly used current protocols by up to 25 minutes. What is known already Vitrification and warming of oocytes is widely used in many IVF clinics worldwide and routinely utilized as a dominant technique for fertility preservation and freezing of donor as well as autologous oocytes in many clinical settings. Outcome data using cryopreserved oocytes is comparable to fresh oocytes. However, vitrification and warming of human oocytes can be time consuming. Usually, vitrification of oocytes is done in about 11-16 minutes, and warming requires another 11 minutes. Also, it is a common practice to load not more than 2 oocytes per carrier at time of vitrification. Study design, size, duration From November 2022 to November 2023, 504 germinal vesicles (GV) and 207 metaphase I (MI) oocytes, which did not convert into mature oocytes at day of oocyte retrieval, were vitrified in Vit Kit Freeze (FujiFilm Irvine Scientific, USA), and RapidVit Oocyte (Vitrolife, Sweden). Their survival rates were compared, and as an additional viability indicator, post-warming developmental capabilities were evaluated after 24 and 48hrs of culture in Global High Protein (LifeGlobal, USA). Participants/materials, setting, methods A group of 4 GV or MI oocytes was vitrified at room temperature for 1 minute in Equilibration solution (ES) and 1 minute in Vitrification solution (VS), loaded on a S-Cryolock (Biotech, USA) and then plunged into liquid nitrogen. Warming was done at 37ºC in 0.5M sucrose for 1 minute and Wash solution (WS) for another minute. Post warming, GV and MI oocytes were cultured for developmental evaluation. Statistical significance was defined as P < 0.05. Main results and the role of chance There was no statistically significant difference in the survival rate of GV oocytes between Irvine (209/219; 95.4%), and Vitrolife media (270/285; 94.7%; P = 0.72). The survival of MI oocytes was also comparable and not significantly different between both media; Irvine: 103/106; 97.2%, vs Vitrolife: 96/101; 95.0%; P = 0.43). Because of the similar survival rates of oocytes in both groups, for the developmental potential and conversion rates, oocytes of both groups were combined. Of the 504 GV, 479 survived (95.0%) and after 24hrs of culture, 441 converted to MI (92.1%). After a culture of 48hrs, 56.5% (249/441) converted to metaphase II (MII) oocytes. Combining the vitrified and warmed MI oocytes from both groups, 96.1% (199/207) survived the warming, and after 24hrs of culture, 168 (84.4%) converted to MII oocytes. Vitrification and warming of oocytes at different developmental stages can be done with a short exposure time to hypertonic (ES/VS) and hypotonic (0.5M sucrose) solutions in a total of 4 minutes. Limitations, reasons for caution Immature oocytes were used as study material to evaluate a new protocol with significantly reduced vitrification and warming times. At this moment we cannot provide data on fertilization, embryo development, and blastocyst formation. Wider implications of the findings Oocytes are exposed to less suboptimal temperatures during dehydration and rehydration and help to maintain their developmental potential. Loading 4 oocytes per carrier combined with the decrease in time resulted in increased efficiency. Warming in 0.5M instead of 1M sucrose contributes positively to survival and allows earlier resumption of functionality. Trial registration number not applicable

Germination responses of Lens Culiunaris L. seeds to osmotic potentials at cardinal temperatures using hydrothermal time model

BackgroundLentil is a significant legume that are consumed as a staple food and have a significant economic impact around the world. The purpose of the present research on lentil was to assess the hydrothermal time model’s capacity to explain the dynamics of Lens culinaris L. var. Markaz-09 seed germination, as well as to ascertain the germination responses at various sub-optimal temperatures (T) and water potentials (Ψ). In order to study lentil seed germination (SG) behavior at variable water potentials (Ψs) and temperatures (Ts). A lab experiment employing the hydrothermal time model was created. Seeds were germinated at six distinct temperatures: 15 0С, 20 0С, 25 0С, 30 0С, 35 0С, and 40 0С, with five Ψs of 0, -0.3, -0.6, -0.9, and − 1.2 MPa in a PEG-6000 (Polyethylene glycol 6000) solution.ResultsThe results indicated that the agronomic parameters like Germination index (GI), Germination energy (GE), Timson germination index (TGI), were maximum in 25 0C at (-0.9 MPa) and lowest at 40 0C in 0 MPa. On other hand, mean germination time (MGT) value was highest at 15 0C in -1.2 MPa and minimum at 40 0C in (-0.6 MPa) while Mean germination rate (MGR) was maximum at 40 0C in (0 MPa) and minimum at 15 0C in (-0.6 MPa).ConclusionsThe HTT model eventually defined the germination response of Lens culinaris L. var. Markaz-09 (Lentil) for all Ts and Ψs, allowing it to be employed as a predictive tool in Lens culinaris L. var. Markaz-09 (Lentil) seed germination simulation models.

Citrullus colocynthis regulates photosynthetic and biochemical processes to develop stress resilience and sustain growth under sub-optimal temperatures

Sub-optimal temperatures posed significant challenges to leaf photosynthesis and plant growth. This study examined the eco-physiological adaptations of a desert vine (Citrullus colocynthis) to unfavorable temperatures (15/25 °C, 25/35 °C, and 35/45 °C) over 35 days. Plants grown in moderate temperatures increased shoot number and leaf canopy (55 %), chlorophyll a (2.5 folds), and carotenoid accumulation compared to other treatments. Conversely, high-temperature stress resulted in longer shoot development with fewer primary branches, while low temperatures constrained both shoot and leaf growth. Plants treated with high heat exposure produced more oxidative stress markers (MDA and H2O2, by two folds), causing greater cellular damage while attaining lesser growth. During the high-temperature episode, plants increased their antioxidant enzyme activities and proline (2.5-fold) levels to protect the tissues from oxidative damage. Plants treated with either moderate or higher heat stress increased the potential quantum yield of photosystem II (Fv/Fm) and maximum quantum yield ФPSII in the young leaves, which indicated the constitutive plant adaptation to unfavorable temperatures. Additionally, photosynthetic efficiency differed with leaf age and temperature; mature leaves performed better physiologically at low temperatures, whereas young leaves adapted better at high temperatures stress. The results suggested that C. colocynthis plants were highly adaptable to unfavorable temperatures by regulating the plants’ thermal homeostatic ability through their photosynthetic and biochemical processes. This study provided deeper insights into species-specific eco-physiological responses to sub-optimal temperatures and contributed to our broader understanding of plant resilience and ecological adaptability in the era of global climate change.