Suboptimal Temperatures Research Articles

Implications of Bacterial Adaptation to Phenol Degradation under Suboptimal Culture Conditions Involving Stenotrophomonas maltophilia KB2 and Pseudomonas moorei KB4

Despite the well-described abundance of phenol-degrading bacteria, knowledge concerning their degradation abilities under suboptimal conditions is still very limited and needs to be expanded. Therefore, this work aimed to study the growth and degradation potential of Stenotrophomonas maltophilia KB2 and Pseudomonas moorei KB4 strains toward phenol under suboptimal temperatures, pH, and salinity in connection with the activity of catechol dioxygenases, fatty acid profiling, and membrane permeability. The methodology used included: batch culture of bacteria in minimal medium supplemented with phenol (300 mg/L), isolating and measuring the activity of catechol 1,2- and 2,3-dioxygenases, calculating kinetic parameters, chromatographic analysis of fatty acid methyl esters (FAMEs) and determining the membrane permeability. It was established that the time of phenol utilisation by both strains under high temperatures (39 and 40 °C) proceeded 10 h; however, at the lowest temperature (10 °C), it was extended to 72 h. P. moorei KB4 was more sensitive to pH (6.5 and 8.5) than S. maltophilia KB2 and degraded phenol 5–6 h longer. Salinity also influenced the time of phenol removal. S. maltophilia KB2 degraded phenol in the presence of 2.5% NaCl within 28 h, while P. moorei KB4 during 72 h. The ability of bacteria to degrade phenol in suboptimal conditions was coupled with a relatively high activity of catechol 1,2- and/or 2,3-dioxygenases. FAME profiling and membrane permeability measurements indicated crucial alterations in bacterial membrane properties during phenol degradation leading predominantly to an increase in fatty acid saturation and membrane permeability. The obtained results offer hope for the potential use of both strains in environmental microbiology and biotechnology applications.

A Synergistic Effect Based on the Combination of Melatonin with 1-Methylcyclopropene as a New Strategy to Increase Chilling Tolerance and General Quality in Zucchini Fruit.

Zucchini fruit are highly sensitive to low temperatures leading to significant peel depressions, increasing weight loss and making them impossible to be commercialized. In this study the effect on the reduction of chilling injury (CI) assaying different postharvest treatments to cv. Cronos was evaluated. We have compared the application of substances such as 1-methylcyclopropene (1-MCP) with the application of a natural origin compound as melatonin (MT), both with demonstrated activity against CI in different vegetal products. The effects of MT (1 mM) by dipping treatment of 1 h and 1-MCP (2400 ppb) have been evaluated on zucchini fruit during 15 days of storage at 4 °C plus 2 days at 20 °C. Treatments applied independently improved some fruit quality parameters in comparison with control fruit but were not able to manage CI even though they mitigated the impact on several parameters. However, when these two separated strategies were combined, zucchini cold tolerance increased with a synergic trend. This synergic effect affected in general all parameters but specially CI, being also the only lot in which zucchini fruit were most effectively preserved. This is the first evidence in which a clear positive effect on zucchini chilling tolerance has been obtained combining these two different strategies. In this sense, the combined effect of 1-MCP and MT could be a suitable tool to reach high quality standards and increasing shelf life under suboptimal temperatures.

Temperature during Seed Maturation Influences Timing of Bud Burst in Seedlings and Saplings of Prunus padus

Climate change increases global average temperatures worldwide. We tested whether temperature during seed maturation in a broadleaved woody perennial may influence the phenological performance of the seedlings. We performed two controlled crosses of Prunus padus L. in two subsequent years (2015 and 2016). Clonal mother shrubs were subjected to a cold and a warm condition during seed maturation. In the first year after germination, the seedlings from the warm seed maturation condition burst their buds earlier compared with the cold condition seedlings. In contrast, in the second and third years, these seedlings burst their buds later. A temporary maternal effect may have advanced bud burst for the warm condition seedlings in the first year, whereas a delay of bud burst in the following years may be caused by a transgenerational epigenetic memory, putatively expressing a stress reaction upon the suboptimal elevated temperature during seed maturation. A warm spring treatment in 2020 enlarged the difference in timing of bud burst between the cold and warm seed maturation conditions in offspring of both crosses, suggesting that the epigenetic memory is more strongly expressed in a warmer spring environment. The timing of the autumnal leaf senescence in the seedlings was not influenced by the temperature during seed maturation in all observation years, suggesting that autumnal senescence is less (epi)genetically determined compared with bud burst and more sensitive to ambient temperatures.

Duration of skin-to-skin care and rectal temperatures in late preterm and term infants

BackgroundHypothermia during the newborn period is widely regarded as a major contributory cause of significant morbidity and mortality of newborn infants. Thermoprotective behaviours such as skin-to-skin care (SSC) or the use of appropriate devices have been recommended as simple tools for the avoidance of neonatal hypothermia. We examined the relation between the duration of skin-to-skin care and infant temperature change after birth in suboptimal delivery room temperatures.MethodsWe reviewed the medical charts of all vaginally born infants of gestational age ≥ 35 weeks born January-July 2018 and admitted to the well-baby nursery. After SSC was discontinued, the infant’s rectal temperature was measured to determine the frequency and severity of hypothermia.ResultsThe charts of 688 vaginally born infants were examined. Our mean delivery room temperature was 21.7 (SD 2.2) °C, well below the WHO recommendation of 25 °C. After SSC 347 (50.4%) infants were normothermic (temperature 36.5–37.5 °C), 262 (38.0%) were mildly hypothermic (36.0-36.4 °C), and 79 (11.4%) were moderately hypothermic (32.0-35.9 °C). The mean skin-to-skin time in infants was 63.9 (SD 20.9) minutes. SSC duration was associated with increase in rectal temperature for patients of gestational ages ≥ 38 weeks and with decrease in rectal temperature in patients of gestational age < 38 weeks.ConclusionSSC is effective, even at suboptimal delivery room temperatures, for promoting normothermia in infants of ≥ 38 weeks’ gestation but may not provide adequate warmth for infants of < 38 weeks.

The thermal performance curve for aerobic metabolism of a flying endotherm.

Performance benefits of stable, warm muscles are believed to be important for the evolution of endothermy in mammals, birds and flying insects. However, thermal performance curves have never been measured for a free-flying endotherm, as it is challenging to vary body temperatures of these animals, and maximal flight performance is difficult to elicit. We varied air temperatures and gas densities to manipulate thoracic temperatures of flying honeybees from 29°C to 44°C, with low air densities used to increase flight metabolic rates to maximal values. Honeybees showed a clear thermal performance curve with an optimal temperature of 39°C. Maximal flight metabolic rates increased by approximately 2% per 1°C increase in thoracic temperature at suboptimal thoracic temperatures, but decreased approximately 5% per 1°C increase as the bees continued to heat up. This study provides the first quantification of the maximal metabolic performance benefit of thermoregulation in an endotherm. These data directly support aerobic capacity models for benefits of thermoregulation in honeybees, and suggest that improved aerobic capacity probably contributes to the multiple origins of endothermic heterothermy in bees and other insects.

Inflorescence temperature influences fruit set, phenology, and sink strength of Cabernet Sauvignon grape berries.

The temperature during the bloom period leading up to fruit set is a key determinant of reproductive success in plants and of harvest yield in crop plants. However, it is often unclear whether differences in yield components result from temperature effects on the whole plant or specifically on the flower or fruit sinks. We used a forced-convection, free-air cooling and heating system to manipulate the inflorescence temperature of field-grown Cabernet Sauvignon grapevines during the bloom period. Temperature regimes included cooling (ambient −7.5°C), heating (ambient +7.5°C), an ambient control, and a convective control. Cooling significantly retarded the time to fruit set and subsequent berry development, and heating shortened the time to fruit set and accelerated berry development relative to the two controls. Fruit set was decreased in cooled inflorescences, but although the cooling regime resulted in the lowest berry number per cluster, it also decreased seed and berry weight at harvest while not affecting seed number. Cooling inflorescences slightly decreased fruit soluble solids and pH, and increased titratable acidity, but did not affect color density. The inflorescence temperature did not impact leaf gas exchange and shoot growth, and shoot periderm formation occurred independently of the timing of fruit ripening. These results suggest that the temperature experienced by grape flowers during bloom time impacts fruit set and subsequent seed and berry development. Suboptimal temperatures not only reduce the proportion of flowers that set fruit but also limit the sink strength of the berries that do develop after fruit set. Shoot vigor and maturation, and leaf physiology, on the other hand, may be rather insensitive to temperature-induced changes in reproductive development.

Impact of the donor hepatectomy time on short-term outcomes in liver transplantation using donation after circulatory death: A review of the US national registry.

During the donor hepatectomy time (dHT), defined as the time from the start of cold perfusion to the end of the hepatectomy, liver grafts have a suboptimal temperature. The aim of this study was to analyze the impact of prolonged dHT on outcomes in donation after circulatory death (DCD) liver transplantation (LT). Using the US national registry data between 2012 and 2020, DCD LT patients were separated into two groups based on their dHT: standard dHT (<42min) and prolonged dHT (≥42min). There were 3810 DCD LTs during the study period. Median dHT was 32min (interquartile range 25-41min). Kaplan-Meier graft survival curves demonstrated inferior outcomes in the prolonged dHT group at 1-year after DCD LT compared to those in the standard dHT group (85.3%vs 89.9%; P<.01). Multivariate Cox proportional hazards models for 1-year graft survival identified that prolonged dHT [hazard ratio (HR) 1.46, 95% confidence interval (CI) 1.19 - 1.79], recipient age ≥ 64 years (HR 1.40, 95% CI 1.14 - 1.72), and MELD score ≥ 24 (HR 1.43, 95% CI 1.16 - 1.76) were significant predictors of 1-year graft loss. Spline analysis shows that the dHT effects on the risk for 1-year graft loss with an increase in the slope after median dHT of 32min. Prolonged dHTs significantly reduced graft and patient survival after DCD LT. Because dHT is a modifiable factor, donor surgeons should take on cases with caution by setting the dHT target of<32min.

Response of F. arundinacea seed germination to temperatures, water potentials, and priming treatments using hydro- and thermal-time models.

The germination process and seedling development are the determining steps in the plant lifecycle that are the most sensitive to adverse environmental conditions. Therefore, this study wasconducted to explore the effects of temperature and osmotic potential on germination responses using threshold models and to establish an optimal priming protocol for improving tolerance responses against osmotic stress in early growth stages. The results demonstrated that osmotic stress of - 0.8MPa significantly influenced the extent, timing, and speed of seed germination. In addition, priming treatments led to an enhanced performance of early growth stages in response to osmotic stress. Based on thermal-time and hydro-time models, the predicted physiological parameters of the median thermal-time at sub-optimal temperature ( h), the median ceiling temperature for 50% germination (Tc(50) = 39.29°C), the common base temperature (Tb = 7.88°C), the constant thermal-time at supra-optimal temperature ( = 805.96°Ch), the threshold water potential (Ψb(50) = - 1.13MPa), and the hydro-time constant ( = 56.09MPah) quantitatively describe the tolerance threshold of the germination process under different osmotic and temperature conditions. The results also showed that the efficiency of seed treatments depended on the priming conditions, including temperature, duration, and also concentration of the priming agent. However, the treatments of gibberellic acid (5days, 10°C, 100ppm), salicylic acid (5days, 10°C, 50ppm), calcium chloride (3days, 10°C, 10mM), potassium nitrate (3days, 10°C, 100mM), and hydro-priming (3days, 10°C) were optimal protocols of each priming method, resulting in an increased seed vigor under osmotic stress. Hence, the predicted biological parameters could easily be applied to determine the physiological changes of germination under environmental factors over time. Also, results suggest that recommended osmo-, hydro-, and hormonal-priming treatments could be efficient methods for ameliorating the osmotic tolerance in the post-priming stages of this plant, especially in arid lands. The online version contains supplementary material available at 10.1007/s12298-022-01229-w.

O efeito da temperatura do ar na mortalidade por doenças cerebrovasculares no Brasil entre 1996-2017

Abstract Cerebrovascular diseases (CVD) are one of the leading causes of mortality globally. Air temperature is one of the risk factors for CVD; however, few studies have investigated the relationship between air temperature and mortality from these diseases in Brazil. This time series study investigated the relationship between air temperature and CVD mortality in 10 microregions located across Brazil’s five regions during the period 1996 to 2017 using mortality data from the national health information system, DATASUS and daily mean temperature data. The association between mean air temperature and mortality from CVD was measured using generalized additive models with Poisson distribution and relative and attributable risks were estimated together with 95% confidence intervals using distributed lag non-linear models and a 14-day lag. There were 531,733 deaths from CVD during the study period, 21,220 of which (11,138-30,546) were attributable to air temperature. Minimum mortality temperatures ranged from 20.1ºC in Curitiba to 29.6ºC in Belém. Associations between suboptimal air temperatures and increased risk of death from CVD were observed in all of Brazil’s five regions. Relative risk from the cold was highest in Manaus (RR 1.53; 1.22-1.91) and Campo Grande (RR 1.52; 1.18-1.94), while relative risk from heat was highest in Manaus (RR 1.75; 1.35-2.26) and Brasília (RR 1.36; 1.15-1.60).

The effect of air temperature on mortality from cerebrovascular diseases in Brazil between 1996 and 2017.

Cerebrovascular diseases (CVD) are one of the leading causes of mortality globally. Air temperature is one of the risk factors for CVD; however, few studies have investigated the relationship between air temperature and mortality from these diseases in Brazil. This time series study investigated the relationship between air temperature and CVD mortality in 10 microregions located across Brazil's five regions during the period 1996 to 2017 using mortality data from the national health information system, DATASUS and daily mean temperature data. The association between mean air temperature and mortality from CVD was measured using generalized additive models with Poisson distribution and relative and attributable risks were estimated together with 95% confidence intervals using distributed lag non-linear models and a 14-day lag. There were 531,733 deaths from CVD during the study period, 21,220 of which (11,138-30,546) were attributable to air temperature. Minimum mortality temperatures ranged from 20.1ºC in Curitiba to 29.6ºC in Belém. Associations between suboptimal air temperatures and increased risk of death from CVD were observed in all of Brazil's five regions. Relative risk from the cold was highest in Manaus (RR 1.53; 1.22-1.91) and Campo Grande (RR 1.52; 1.18-1.94), while relative risk from heat was highest in Manaus (RR 1.75; 1.35-2.26) and Brasília (RR 1.36; 1.15-1.60).

Post-Hatch Performance of Broilers Following Hypoxic Exposure During Incubation Under Suboptimal Environmental Temperature.

The modern broiler is selected to exploit its full genetic potential, to sustain a rapid growth rate, and to lower the feed conversion rate (FCR). Recently reported reductions in FCR have been associated with augmented tissue formation at the expense of physiological functions such as thermoregulation. In turn, modern broilers exhibit a relatively low capability to balance energy expenditure under suboptimal ambient temperature. Hypoxic conditions at late incubation stages play a role in reforming metabolic plasticity. This work examined the effect of exposure to 12-h hypoxia (12H; 17% O2) for three consecutive days (from E16 through E18), or continuous hypoxia exposure for 48 h (48H), from E16 through E17, as compared to standard incubation (21% O2) on post-hatch performance of broilers maintained under suboptimal ambient temperatures (cold, hot, and diurnal cyclic ambient temperature). 12H chicks kept under hot ambient temperature had significantly lower body temperature (Tb) as compared to the control chicks. On day 42, both 12H and 48H chicks grown in the cyclic temperature room had significantly lower Tbs than controls. In parallel, from week 4, onward, 12H chicks had a significantly lower FCR than controls, and the 48H chicks demonstrated a lower FCR from week 5 and on. 12H and 48H broilers maintained under diurnal cyclic ambient temperature, exhibited significantly greater relative breast muscle weight, and a similar pattern was found in hypoxic broilers raised under standard and hot ambient temperatures. Hypoxic manipulation affects and create an adaptive bias in allocating metabolic energy between maintenance and growth, thus resulting in improved broiler performance, thermoregulation, and rearing under suboptimal environmental temperature.

Temperature variability interacts with mean temperature to influence the predictability of microbial phenotypes.

Despite their relatively high thermal optima (T opt), tropical taxa may be particularly vulnerable to a rising baseline and increased temperature variation because they live in relatively stable temperatures closer to their T opt. We examined how microbial eukaryotes with differing thermal histories responded to temperature fluctuations of different amplitudes (0 control, ±2, ±4°C) around mean temperatures below or above their T opt. Cosmopolitan dinoflagellates were selected based on their distinct thermal traits and included two species of the same genus (tropical and temperate Coolia spp.), and two strains of the same species maintained at different temperatures for >500 generations (tropical Amphidinium massartii control temperature and high temperature, CT and HT, respectively). There was a universal decline in population growth rate under temperature fluctuations, but strains with narrower thermal niche breadth (temperate Coolia and HT) showed ~10% greater reduction in growth. At suboptimal mean temperatures, cells in the cool phase of the fluctuation stopped dividing, fixed less carbon (C) and had enlarged cell volumes that scaled positively with elemental C, N, and P and C:Chlorophyll‐a. However, at a supra‐optimal mean temperature, fixed C was directed away from cell division and novel trait combinations developed, leading to greater phenotypic diversity. At the molecular level, heat‐shock proteins, and chaperones, in addition to transcripts involving genome rearrangements, were upregulated in CT and HT during the warm phase of the supra‐optimal fluctuation (30 ± 4°C), a stress response indicating protection. In contrast, the tropical Coolia species upregulated major energy pathways in the warm phase of its supra‐optimal fluctuation (25 ± 4°C), indicating a broadscale shift in metabolism. Our results demonstrate divergent effects between taxa and that temporal variability in environmental conditions interacts with changes in the thermal mean to mediate microbial responses to global change, with implications for biogeochemical cycling.

The results of single well chemical tracer tests to assess the effectiveness of surfactant-polymer exposure at the Kholmogorskoye field

Methods of enhanced oil recovery in general and surfactant-polymer flooding in particular are considered as tertiary methods for the development of mature oil fields in Western Siberia, with the potential to increase oil recovery to 60-70% of the initial geological reserves.&#x0D; To select an effective mixture of surfactants and polymer for surfactantpolymer flooding, laboratory tests were carried out in which the thermal stability, phase behaviour, interfacial tension and rheology of the formulations were tested. Filtration experiments were also carried out to optimize the volumes of injected fringes and the concentrations of reagents in them. At the final stage, single well chemical tracer tests (SWCTT) were carried out to assess the effectiveness of surfactant-polymer flooding on two wells of the Kholmogorskoye field. In order to investigate different technical and economic models of surfactant-polymer exposure, SWCTT tests were conducted with the same surfactant, but with a different design. The results of the SWCTT tests showed that the residual oil saturation in the affected area after injection of the surfactant-polymer solution decreased by about 11% compared to water flooding, which is about a third of the residual oil after flooding. The tested surfactant showed acceptable efficiency under suboptimal temperature conditions, which is favorable for the use of the selected surfactant-polymer composition for neighboring deposits and formations with different reservoir temperatures, but similar water composition.&#x0D; In general, the results of the conducted field tests correlate with the results of the main laboratory experiments for the selected surfactant.

The effect of dietary protein level and amino acid supplementation on the Nile tilapia (Oreochromis niloticus) nursering performance under biofloc system conditions at a cold suboptimal water temperature

The effect of dietary protein level and amino acid supplementation on the Nile tilapia (Oreochromis niloticus) nursering performance under biofloc system conditions at a cold suboptimal water temperature

A combined technique of temperature preconditioning and modified atmosphere packaging to prolong the storage life of papaya

Papaya is a popular tropical fruit for human consumption over the world. However, it has a relatively short shelf life due to rapid ripening and anthracnose infection after harvest. Generally, papaya is stored at the optimum temperature of 12°C and can last only two weeks. After this period, the fruit will begin to ripen and spoil. Theoretically, fruit stored at lower temperatures will have a longer shelf life. However, papaya is prone to chilling injuries characterised by pitting and inability to ripen if stored at sub-optimum temperature, which may also cause secondary postharvest disease attacks if held for a longer period. The study aimed to evaluate the effectiveness of a combination of temperature preconditioning treatment and modified atmospheric packaging (MAP) in prolonging the storage life of papaya under sub-optimum temperature. In terms of visual appearance, no chilling injury symptoms were observed in samples stored at a suboptimum temperature of 7°C throughout the storage period. No significant differences were recorded in the parameters of total soluble solids (TSS), total titratable acidity (TTA) and TSS: TTA ratio. Relatively lower ascorbic acid content and higher firmness value were recorded in fruits subjected to the combined technique of temperature conditioning and MAP, which could be associated with delayed ripening. A combination of temperature preconditioning and MAP techniques maintains the papaya quality under storage at sub-optimum temperatures as low as 7°C without chilling injury problems, with a longer shelf life (4 weeks) than only 2 weeks for conventional handling techniques. The fruits can be ripened by being exposed to ethylene when they are ready to be marketed. The technology is helpful for the industry, farmers, wholesalers, and exporters, particularly for the delivery of more extended distribution and periods.

Global climate change and human health: Pathways and possible solutions

Global warming has been changing the planet’s climate pattern, leading to increasing frequency, intensity and duration of extreme weather events and natural disasters. These climate-changing events affect various health outcomes adversely through complicated pathways. This paper reviews the main signs of climate change so far, e.g., suboptimal ambient temperature, sea-level rise and other conditions, and depicts the interactive pathways between different climate-changing events such as suboptimal temperature, wildfires, and floods with a broad range of health outcomes. Meanwhile, the modifying effect of socioeconomic, demographic and environmental factors on the pathways is summarised, such that the youth, elderly, females, poor and those living in coastal regions are particularly susceptible to climate change. Although Earth as a whole is expected to suffer from climate change, this review article discusses some potential benefits for certain regions, e.g., a more liveable environment and sufficient food supply. Finally, we summarise certain mitigation and adaptation strategies against climate change and how these strategies may benefit human health in other ways. This review article provides a comprehensive and concise introduction of the pathways between climate change and human health and possible solutions, which may map directions for future research.

The Effects of Carbon Source and Growth Temperature on the Fatty Acid Profiles of Thermobifida fusca.

The aerobic, thermophilic Actinobacterium, Thermobifida fusca has been proposed as an organism to be used for the efficient conversion of plant biomass to fatty acid-derived precursors of biofuels or biorenewable chemicals. Despite the potential of T. fusca to catabolize plant biomass, there is remarkably little data available concerning the natural ability of this organism to produce fatty acids. Therefore, we determined the fatty acids that T. fusca produces when it is grown on different carbon sources (i.e., glucose, cellobiose, cellulose and avicel) and at two different growth temperatures, namely at the optimal growth temperature of 50°C and at a suboptimal temperature of 37°C. These analyses establish that T. fusca produces a combination of linear and branched chain fatty acids (BCFAs), including iso-, anteiso-, and 10-methyl BCFAs that range between 14- and 18-carbons in length. Although different carbon sources and growth temperatures both quantitatively and qualitatively affect the fatty acid profiles produced by T. fusca, growth temperature is the greater modifier of these traits. Additionally, genome scanning enabled the identification of many of the fatty acid biosynthetic genes encoded by T. fusca.

How do suboptimal temperatures affect polyploid sterlet Acipenser ruthenus during early development?

Sturgeons are ancient fish exhibiting unique genome plasticity and a high tendency to produce spontaneously autopolyploid genome states. The temperature profiles of the rivers in which sturgeon live and reproduce have been severely altered by human intervention, and the effect of global warming is expected to cause further temperature shifts, which may be detrimental for early developmental stages with narrow windows of thermal tolerance. The comparison of the performance of diploid and autopolyploid sturgeon kept at unfavourable temperatures contributes to scientific knowledge of the effects of polyploid genome states on organisms and can shed light on the ability of polyploids to cope with human-induced alterations to natural conditions. Using the sterlet Acipenser ruthenus as a model species, we carried out conventional artificial fertilization, as well as the induction of the second polar body retention (SPBR), of the first mitotic division suppression (FMDS) and of the second polar body retention followed by the first mitotic division suppression (SPBR+FMDS). Two experiments were conducted to evaluate the effect of polyploidy on two basic performance parameters, survival and growth. In Experiment 1, fish belonging to untreated, SPBR-, FMDS- and SPBR+FMDS-induced groups were kept at 10, 16 and 20°C from the neurula stage until the end of endogenous feeding. In Experiment 2, larvae from the untreated and SPBR-induced groups were reared at 10, 16 and 20°C after their endogenous feeding transition for 3 weeks. Based on our findings, we report that the embryos, prelarvae and larvae of triploid A.ruthenus do not differ from diploids in their ability to survive, grow and develop under suboptimal temperature conditions, while the survival of tetraploids was significantly reduced even at the optimal temperature and even more so at temperatures far from the optimum. This was also the case in the 2n/4n mosaics observed in FMDS-induced group. Thus, we assume that in tetraploid and 2n/4n individuals, the limits of thermal tolerance are closer to the optimum than in diploids. We also conclude that the hexaploid genome state is probably lethal in A.ruthenus since none of the hexaploids or 3n/6n mosaics arising from the SPBR+FMDS induction survived the prelarval period.

Prediction of mungbean yellow mosaic virus disease using multiple regression models

BackgroundThe main cause for low mungbean [Vigna radiata (L.) R. Wilczek] productivity is mungbean yellow mosaic virus (MYMV). Generally, the management of MYMV relies upon frequent insecticide sprays to control its vector (whitefly) and genetic resistance. However, disease forecast models can help to economize the pesticide sprays. Hence current study was designed to identifying environmental factor that promote disease development and developing a disease prediction model. MethodsOne hundred and twenty-seven mungbean accessions were planted for two years (2012 and 2013) and infection was dependent on natural inoculum. Weekly and daily data on disease incidence and environmental variables were collected and analyzed using correlation and stepwise regression analysis. ResultsWind velocity and high temperature had a negative relation with disease occurrence during both years, whereas low temperature, rainfall, and relative humidity, had positive relationship based on linear regression. The environmental conditions responsible for the highest disease incidence were, maximum temperature (32–34 °C), relative humidity (72–75 %), minimum temperature (27–29 °C), rainfall (1.8–2.1 mm) and wind velocity (3–4.5 km/hr) during both growing seasons Overall, five environmental variable multiple regression model encompassing relative humidity, wind speed, rainfall, suboptimum temperature, and optimum temperatures accommodate the data rightly explaining 83 % variation in disease outgrowth. ConclusionThe observed MYMV disease occurrence values for most of the mungbean genotypes, and those predicted by the model were very close. This multi-environmental variable model can be utilized to provide early warning forecasts for the management of MYMV in Pakistan.

Genome-wide effect of non-optimal temperatures under anaerobic conditions on gene expression in Saccharomyces cerevisiae

Understanding of thermal adaptation mechanisms in yeast is crucial to develop better-adapted strains to industrial processes, providing more economical and sustainable products. We have analyzed the transcriptomic responses of three Saccharomyces cerevisiae strains, a commercial wine strain, ADY5, a laboratory strain, CEN.PK113-7D and a commercial bioethanol strain, Ethanol Red, grown at non-optimal temperatures under anaerobic chemostat conditions. Transcriptomic analysis of the three strains revealed a huge complexity of cellular mechanisms and responses. Overall, cold exerted a stronger transcriptional response in the three strains comparing with heat conditions, with a higher number of down-regulating genes than of up-regulating genes regardless the strain analyzed. The comparison of the transcriptome at both sub- and supra-optimal temperatures showed the presence of common genes up- or down-regulated in both conditions, but also the presence of common genes up- or down-regulated in the three studied strains. More specifically, we have identified and validated three up-regulated genes at sub-optimal temperature in the three strains, OPI3, EFM6 and YOL014W. Finally, the comparison of the transcriptomic data with a previous proteomic study with the same strains revealed a good correlation between gene activity and protein abundance, mainly at low temperature. Our work provides a global insight into the specific mechanisms involved in temperature adaptation regarding both transcriptome and proteome, which can be a step forward in the comprehension and improvement of yeast thermotolerance.