Cold Temperature Stress Research Articles

Surprisingly wide climatic niche breadth of a relict mountain species raises hope for survival under climate change

AbstractAimsWe assessed the juvenile climatic niche breadth of a relict mountain species by comparing field observations and transplant experiments within and beyond the elevational limits of its distribution range.LocationLebanon – Near East – Mediterranean region.MethodsWe studied the survival and growth of the Cedar of Lebanon (Cedrus libani) to determine the lower and upper elevational range limits of its juvenile stage through an experimental setup with and without water supplementation and with potentially competing species as a control. The experiment included eight common gardens at elevations ranging from 110 to 2330 m, within and far beyond the warm and cold limits of Cedar distribution observed under natural conditions.ResultsWe observed unexpectedly high survival and growth rates of Cedar at elevations well below the range of its natural distribution in Lebanon. Below the observed warm limit, water stress at very low elevations and competition at low and medium elevations limited juvenile survival. In contrast, cold temperature and water stress limited survival at elevations slightly above the observed upper natural limit. The experimental setup demonstrated that the elevation range suitable for Cedar growth and survival was twice as wide as the range within which Cedar is observed under natural conditions.Main ConclusionsHigh survival rates experimentally observed beyond the warm limit of the natural distribution range of the Cedar of Lebanon raise hope for its resilience to ongoing climate warming. If this pattern were frequent among montane species, it would challenge predictions of massive extinction with climate change and pave the way for promoting adaptive actions such as competition management to improve their survival.

Safety Assessment of Camelid-Derived Single-Domain Antibody as Feed Additive for Juvenile Whiteleg Shrimp (Litopenaeus vannamei) Against White Spot Syndrome Virus.

A six-week feeding trial was conducted to assess the safety of single-domain antibodies (sdAbs) derived from camelids against the white spot syndrome virus (WSSV) (WSSVvp28 was used as the antigen), focusing on the whole-organism responses and molecular-level changes in juvenile whiteleg shrimp (Litopenaeus vannamei). Five experimental diets with varying levels of sdAbs were formulated: CON (no sdAb supplementation); SDA8.2 (8.20% of sdAbs); SDA16.4 (16.40% of sdAbs); SDA24.6 (24.60% of sdAbs); and SDA32.8 (32.80% of sdAbs). In the CON diet, 450 mL of water per kg of diet (45%) was used to form a feed dough, while sdAbs were used to replace the water in the treatment diets. A total of 450 shrimp, with an initial body weight of 3.27 ± 0.02 g (mean ± SEM), were randomly distributed in 15 tanks (30 shrimp per tank; three tanks per treatment). Each tank was filled with 30 L of seawater (77 L capacity) in an indoor semi-recirculating system with a constant water flow rate of 1.2 L min-1. The photoperiod was maintained at 12 h of light and 12 h of dark. The water temperature, pH, salinity, and dissolved oxygen were 27.3 ± 0.1 °C, 7.61 ± 0.01, 34 ± 1 ppt, and 5.94 ± 0.04 mg L-1, respectively. During the feeding trial, the shrimp were fed the experimental diet (40% protein and 11% lipid) three times a day for six weeks. Following the feeding trial, an acute cold-water-temperature stress test was conducted by abruptly exposing the shrimp from each treatment to 15 °C for 4 h, down from 27 °C. The results showed no significant differences in the growth performance (weight gain, feed utilization efficiency, survival, etc.), plasma metabolites (aspartate aminotransferase activity, alanine aminotransferase activity, total protein, and glucose), or antioxidant enzymes (superoxide dismutase and glutathione peroxidase) among all the experimental diets (p > 0.05). In the acute cold-temperature stress test, there was no significant interaction between sdAb supplementation and temperature stress, nor any main effect from either factor, except for the main effect of temperature stress on the glucose levels, which was significantly higher in shrimp exposed to cold-temperature stress (p < 0.05). The next-generation sequencing of differentially expressed genes (DEGs) in the hepatopancreases of shrimp fed the CON, SDA16.4, and SDA32.8 diets, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, indicated that DEGs were significantly enriched in signaling pathways associated with growth, cold stress, and antioxidant systems. Overall, the results from conventional measurements suggest that the use of sdAbs against the WSSV may be safe for juvenile whiteleg shrimp. However, findings from the sophisticated analysis indicate that further research is needed to understand the molecular mechanisms underlying the observed changes, and to evaluate the long-term effects of sdAb supplementation in shrimp diets.

Formation Rate and Energy Efficiency of Ice Plug in Pipelines Driven by the Cascade Utilization of Cold Energy

Ice plug technology is an effective method for isolating the pipeline system, which are promising methods utilized in the nuclear, chemical, and power industries. To reduce the cold energy consumption and temperature stress, the multi-stage (1–10) of time-dependent thermal boundary conditions was proposed for the formation of ice plug, while the gradient cooling wall temperature of multi-stage was applied. A numerical model considering the liquid–solid phase change, heat transfer, and time-dependent thermal boundary condition has been established. The effects of the ratio of length and diameter of the cooling wall lc/d (1–9) on the formation rate and heat flux of ice plug in the pipe has been investigated. The fastest formation rate of ice plug with 800 mm in the axial direction (7.47 cm3/s) was observed in the pipe with the lc/d of 5. The formation rate of ice plug and the ice formation volume under unit energy consumption VE under various stages (1–10) of cooling wall temperature have been compared. The VE of eight temperature stages (1.45 cm3/kJ) was 1.16 times than the VE of one temperature stage, which satisfied the freezing rate at the same time. This investigation provides insight for proposing an energy-saving system for the formation of ice plug.

Temperature stress (cold and heat) strongly affect the phytotoxicity of polycyclic aromatic hydrocarbon (phenanthrene) to wheat

AbstractAnthropogenic activity could create different threats leading to irreversible changes in the global environment and, as a consequence, posing varied stressful conditions acting together (combined stress) on organisms. Our research concerned the combined stress of two of the main threats to soil health and plant health: temperature stress and pollution. The aim of this research was the quantitative assessment of the impact of temperature stress on the phytotoxicity of PAHs (polycyclic aromatic hydrocarbons; specifically, phenanthrene, which is a widespread, harmful organic contamination of soil) on the growth of wheat seedlings in relation to the level of soil contamination by phenanthrene (0–1000 mg kg−1 dry mass of soil) and the type of temperature stress: cold (10°C) and heat (35°C) stress, in three different soils. Earlier studies have investigated the effect of temperature stress on PAH toxicity mainly on soil invertebrates. However, the impact of temperature stress on PAH phytotoxicity towards crop plants, which are important for human food security but could be affected by chemical soil degradation, is still poorly understood. Our results indicated that the phenanthrene phytotoxicity was significantly enhanced by cold stress and heat stress. The effects of cold and heat temperature stress increased with increasing phenanthrene level. Our research is important for improving the risk assessment of PAH and food security forecasting.

Increasing the resistance of the hollyhock plant to cold stress: silicon or selenium

It is well-known that freezing affects crop growth worldwide and significantly reduces crop production in the affected regions. The study objective was to investigate the effect of sodium silicate and sodium selenite individually or in combination on Alcea rosea plants grown under cold temperature stress. In this work, hollyhock plants were grown with sodium selenite and sodium silicate to 1/2 Hoagland solution, including 1) control, 1 mM sodium sulfate, 2) 1 mM sodium silicate 3), 0.03 mM sodium selenite, 4) 1 mM sodium silicate + 0.03 mM sodium selenite and exposed to nonfreezing (20 °C) and freezing temperature (−4 °C). Nutritional elements, photosynthesis parameters, electrolyte leakage, malondialdehyde, water content, osmolytes, and antioxidant enzymes were determined. The application of Si + Se effectively enhanced the Si and Se content of leaves (54% and 164%) compared to control plants. The combined Si and Se addition increased phenols, water-soluble sugars, proline, chlorophyll, net photosynthesis (Pn), and stomatal size under cold stress. Moreover, Si and Se in combination in stressed plants inhibited electrolyte leakage and malondialdehyde (MDA) by increasing the activities of enzymes such as superoxidase dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT). The maximal to minimal values of essential oil content, relative water content (RWC), and stomatal density depended on the treatment: Si + Se > Si = Se. By increasing K content, phenol, proline, and water-soluble sugars, Si + Se > Si > Se application decreased the adverse effects of cold stress on the dry weight of the hollyhock.

Larval instar estimation and ultra‐structural analysis of Aphaenogaster cristata (Forel, 1902) and Aphaenogaster pachei (Forel, 1906) (Hymenoptera: Formicidae) from the Himalayas

AbstractThe ontogeny of an organism provides fundamental insights into its life history and evolutionary background. Among insects, especially ants, relatively few observations have been formalized about the morphology of immature stages. Using light and scanning electron microscopy, this study presents the first description of the different larval instars of Aphaenogaster cristata (Forel, 1902) and Aphaenogaster pachei (Forel, 1906), species endemic to the Himalayas that predominate in areas where cold temperature stress and disturbances limit the presence of other ants. The existence of four larval instars was estimated based on the frequency distribution of their measured maximum head widths. We observed discrete alterations in the body constitution and parts among the different instars, suggesting they must follow similar habits until pupation. The two species, however, present noticeable particularities in their mandibles and hair types, suggesting intrinsic life adaptations. Observed traits complementary with previous descriptions with larvae of the genus and related taxa are suggestive of considerable evolutionary distance from Messor, considered the sister clade, which merits further taxonomic investigation in future studies.

Cold temperature stress and damaged skin induced high mortality in barramundi (Lates calcarifer) challenged with Vibrioharveyi.

Most diseases in aquaculture are caused by opportunistic pathogens. One of them, Vibrio harveyi, is a widespread Gram-negative bacterium that has become an important pathogen of aquatic species in marine environments. Here, we propose the use of the causal pie model as a framework to conceptualize the causation of vibriosis in juvenile barramundi (Lates calcarifer) and to establish an effective challenge model. In the model, a sufficient cause, or the causal pie, is a constellation of component causes that lead to an outcome (e.g. vibriosis). In the pilot study, a high cumulative mortality (63.3% ± 10.0%, mean ± SE) was observed when V. harveyi was administered by intraperitoneal injection using a high challenge dose [107 colony-forming units (CFU) fish-1 ], but low or no mortality was observed in fish subject to cold stress or fish with intact skin when challenged by immersion. We, therefore, tested the use of a skin lesion (induced with a 4-mm biopsy punch) combined with cold temperature stress to induce vibriosis following the causal pie model. After challenge, fish were immediately subject to cold stress (22°C) or placed at an optimal temperature of 30°C. All groups were challenged with 108 CFU mL-1 for 60 min. A considerably higher mortality level (72.7% ± 13.9%) was observed in fish challenged with both a skin lesion and cold stress compared with mortality in fish only having a skin lesion (14.6% ± 2.8%). V. harveyi was re-isolated from all moribund fish and was detected by species-specific real-time PCR in gills, head kidney and liver, regardless of challenge treatment confirming vibriosis as the cause of disease. Parenchymal tissues had histopathological changes consistent with vibriosis. Whole-genome sequence (WGS) is provided for the Vibrio harveyi isolate examined in this study. Overall, the causal pie model was a useful framework to conceptualize the design of the experimental challenge model, in which both cold stress and skin damage were identified as component causes of vibriosis with high mortality. This conceptual framework can be applied to other opportunistic pathogens in aquaculture or to the study of co-infections in fish.

Heterologous overexpression of the cyanobacterial alcohol dehydrogenase sysr1 confers cold tolerance to the oleaginous alga Nannochloropsis salina.

Temperature is an important regulator of growth in algae and other photosynthetic organisms. Temperatures above or below the optimal growth temperature could cause oxidative stress to algae through accumulation of oxidizing compounds such as reactive oxygen species (ROS). Thus, algal temperature stress tolerance could be attained by enhancing oxidative stress resistance. In plants, alcohol dehydrogenase (ADH) has been implicated in cold stress tolerance, eliciting a signal for the synthesis of antioxidant enzymes that counteract oxidative damage associated with several abiotic stresses. Little is known whether temperature stress could be alleviated by ADH in algae. Here, we generated transgenic lines of the unicellular oleaginous alga Nannochloropsis salina that heterologously expressed sysr1, which encodes ADH in the cyanobacterium Synechocystis sp. PCC 6906. To drive sysr1 expression, the heat shock protein 70 (HSP70) promoter isolated from N. salina was used, as its transcript levels were significantly increased under either cold or heat stress growth conditions. When subjected to cold stress, transgenic N. salina cells were more cold-tolerant than wild-type cells, showing less ROS production but increased activity of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, and catalase. Thus, we suggest that reinforcement of alcohol metabolism could be a target for genetic manipulation to endow algae with cold temperature stress tolerance.

Growth, photosynthetic pigment proteins responses and transcriptome analysis provide insights into survival strategies against short-term cold stress in the blue-green algae, Arthrospira

Arthrospira species are widely cultivated due to their high nutritional value as a food supplement. The fluctuating temperature strongly influences the cultivation system for Arthrospira mass production. To reveal the underlying mechanisms of coping with temperature stress to adopt measures of harm reduction, we analyzed changes in growth, photosynthetic pigments and the transcriptome of Arthrospira sp. TJSD091 exposed to short-term cold stress. The photosynthetic pigments decreased significantly under cold temperature stress conditions, and so as the cells` dry weight. A total of 1294 genes were expressed differentially. Pathway analysis revealed 473 differentially expressed genes were identified in 32 KEGG pathways, of which 309 genes (65.33 %) are involved in the most affected metabolic pathway. The most sensitive metabolic pathways in response to cold stress involved energy metabolism, carbohydrate metabolism and photosynthesis proteins. The key hub regulatory genes were perceived as cyaA and genes related to two-component signal transduction systems. The genes regulated diverse metabolic functions to survive and grow. The increased respiration provided essential energy for basic motility maintenance under cold stress. The down-regulation of genes involved in photosynthesis, glycolysis, Calvin cycle and citrate cycle supported the low biomass production of the blue-green algae. The results provide a basis for revealing the survival mechanism of the blue-green algae to withstand cold stress at the gene transcription level.

Long non-coding RNA LncMPEG1 responds to multiple environmental stressors by affecting biomineralization in pearl oyster Pinctada fucata martensii

Marine environmental change directly affects bivalve growth and survival. Exoskeleton formation, the main energy dissipation in the physiological metabolism, typically reflects the body growth of the bivalve. However, how bivalves regulate the biomineralization of the exoskeleton under environmental stressors is not yet clear. Long non-coding RNA regulates various life processes through complex mechanisms in vertebrates and invertebrates. In this research, we cloned the complete sequence of a mantle-specific expressed long non-coding RNA (designated as LncMPEG1) from a pearl oyster, Pinctada fucata martensii. A quantitative real-time PCR analysis showed that LncMPEG1 expression was significantly high in early umbo larvae and juveniles, which would be the critical periods of shell development. LncMPEG1 was identified in the outer epithelium of the middle fold from the mantle edge, mantle pallial, and mantle center by using in situ hybridization. Additionally, the expression of LncMPEG1 was stimulated by shell damage, alien invasion, heat and cold temperature stress, and hypoxia stress. In the mantle, a decreased in LncMPEG1 expression was detected by RNA interference, which can cause the irregular growth of crystals on the inner surface of the prismatic layer and nacre in the shells. Therefore, we propose that LncMPEG1 could be a key regulator in biomineralization and responds to environmental stress in the mantle .

Differential Transcriptome Analysis Reveals Genes Related to Low- and High-Temperature Stress in the Fall Armyworm, Spodoptera frugiperda.

The fall armyworm (FAW), Spodoptera frugiperda, is regarded as one of the world’s most harmful plant pests. This research examines the molecular response processes of FAW to low temperature (4°C) and high temperature (40°C) when gene expression is compared to controls (25°C). A total of 211,967 unigenes were collected, at least 14,338 of which were annotated with gene descriptions, gene ontology terms, and metabolic pathways. There were 50 Gene Ontology (GO) functional sub-groups and 21 EggNOG words as a result. Differentially expresses genes (DEGs) with log2FC ≥ 2 were identified and compared at various temperatures. In comparison to the 25°C treated group, we discovered 199 and 1,248 individual DEGs co-regulated at 4 and 40°C, respectively. Comparing transcriptome profiles for differential gene expression revealed a number of DEGs, including cytochrome P450, odorant binding proteins (OBPs), and immune system genes previously implicated in cold and high temperature stresses. The enrichment pathways were identified using Kyoto Encyclopedia of Genes and Genomics (KEGG) analysis, and heatmaps of similar unigenes from both treatment groups (T4 and T40) were plotted. We used quantitative reverse transcription PCR (RT-qPCR) to confirm the RNA-seq data on 10 up- and down-regulated DEGs. These findings provide a foundation for future understanding of FAW adaptation mechanisms and the underlying basis underlying the response to low and high temperatures.

Improving subtropical cotton production by using late winter sowing to reduce climatic risk

• Late-winter sowing to avoid coinciding boll development and harvest with unfavourable climatic factors was explored. • Crop establishment was successful despite temperatures being well below accepted cold stress thresholds. • Earlier sowing coincided peak boll demand with improved conditions maximising growth and reproductive partitioning. • Lint yield increased over 40 % with late-winter sowing compared to traditional spring sowing. Climate variability is a challenge to the reliable production of high yielding cotton, Gossypium hirsutum L. in the subtropics. Shifting the growing season earlier by sowing during late winter (August) to reduce the risk of exposure to unfavourable radiation, temperature and rainfall during mid-summer offered the potential to improve stagnating and variable yields. This study aimed to determine the effect of late winter sowing on establishment, growth, development and lint yield of cotton. Accepted knowledge from temperate climates suggested cold temperature stress would impede crop establishment, so the application of clear oxodegradable film to the soil surface at sowing to mitigate cold temperature stress was also explored. Crop establishment, biomass accumulation and partitioning, light interception and lint yield were measured for cotton sown with and without film at intervals from early August to mid-September in four consecutive experiments (2013–2016). The application of film provided no benefits for establishment and only marginal improvement for crop growth and yield despite minimum temperatures being well below accepted chilling injury thresholds in temperate environments. Greater daily solar radiation levels both solarised the soil and shortened the duration of daily minimum temperatures, enabling successful crop establishment. Early sowing did not hinder crop production, and in 3 of the 4 experiments, lint yield was significantly higher ( P < 0.001) for August (2314−3305 kg ha −1 ) than September-sown crops (2053−2290 kg ha −1 ). The impact of sowing time was further explored through the measurement of biomass and yield of 29 high input commercial crops sown between August and December in 2016–2019. Final biomass and lint yield declined ( P < 0.001) by 2.89 g m -2 and 7.23 kg ha −1 for each day that sowing occurred after August 1. Combined analyses of the experiments and commercial crop data confirmed that late-winter sown crops had the highest daily growth rate between flowering and maturity, declining by 37 % for summer-sown crops. RUE g (glucose equivalent) of 2.27 g MJ −1 PAR was not changed by sowing time. Late winter sowing best matched flowering and boll development with the summer solstice and a lower incidence of cloud or heat stress. An earlier harvest also reduced the risk of pre-harvest weathering, collectively enabling over 40 % higher yields than traditional spring sowing without additional crop inputs. Spring and later sowings coincided unfavourable climate with the more susceptible growth phases of late boll filling or early flowering respectively and declining solar radiation and temperatures prevented yield recovery for the latest summer-sown crops. As the occurrence of excessive temperature-related weather events is expected to increase with climate change, particularly for the subtropics, this study demonstrates how a knowledge of crop response can be used to evolve sowing time strategies to better mitigate climatic risk.

The thiol-disulfide exchange activity of AtPDI1 is involved in the response to abiotic stresses

BackgroundArabidopsis protein disulfide isomerase 1 (AtPDI1) has been demonstrated to have disulfide isomerase activity and to be involved in the stress response. However, whether the anti-stress function is directly related to the activities of thiol-disulfide exchange remains to be elucidated.ResultsIn the present study, encoding sequences of AtPDI1 of wild-type (WT) and double-cysteine-mutants were transformed into an AtPDI1 knockdown Arabidopsis line (pdi), and homozygous transgenic plants named pdi-AtPDI1, pdi-AtPDI1m1 and pdi-AtPDI1m2 were obtained. Compared with the WT and pdi-AtPDI1, the respective germination ratios of pdi-AtPDI1m1 and pdi-AtPDI1m2 were significantly lower under abiotic stresses and exogenous ABA treatment, whereas the highest germination rate was obtained with AtPDI1 overexpression in the WT (WT- AtPDI1). The root length among different lines was consistent with the germination rate; a higher germination rate was observed with a longer root length. When seedlings were treated with salt, drought, cold and high temperature stresses, pdi-AtPDI1m1, pdi-AtPDI1m2 and pdi displayed lower survival rates than WT and AtPDI1 overexpression plants. The transcriptional levels of ABA-responsive genes and genes encoding ROS-quenching enzymes were lower in pdi-AtPDI1m1 and pdi-AtPDI1m2 than in pdi-AtPDI1.ConclusionTaken together, these results clearly suggest that the anti-stress function of AtPDI1 is directly related to the activity of disulfide isomerase.

In Situ Monitoring of Protein Unfolding/Structural States under Cold High-Pressure Stress.

Biopharmaceutical formulations may be compromised by freezing, which has been attributed to protein conformational changes at a low temperature, and adsorption to ice-liquid interfaces. However, direct measurements of unfolding/conformational changes in sub-0 °C environments are limited because at ambient pressure, freezing of water can occur, which limits the applicability of otherwise commonly used analytical techniques without specifically tailored instrumentation. In this report, small-angle neutron scattering (SANS) and intrinsic fluorescence (FL) were used to provide in situ analysis of protein tertiary structure/folding at temperatures as low as -15 °C utilizing a high-pressure (HP) environment (up to 3 kbar) that prevents water from freezing. The results show that the α-chymotrypsinogen A (aCgn) structure is reasonably maintained under acidic pH (and corresponding pD) for all conditions of pressure and temperature tested. On the other hand, reversible structural changes and formation of oligomeric species were detected near -10 °C via HP-SANS for ovalbumin under neutral pD conditions. This was found to be related to the proximity of the temperature of cold denaturation of ovalbumin (TCD ∼ -17 °C; calculated via isothermal chemical denaturation and Gibbs-Helmholtz extrapolation) rather than a pressure effect. Significant structural changes were also observed for a monoclonal antibody, anti-streptavidin IgG1 (AS-IgG1), under acidic conditions near -5 °C and a pressure of ∼2 kbar. The conformational perturbation detected for AS-IgG1 is proposed to be consistent with the formation of unfolding intermediates such as molten globule states. Overall, the in situ approaches described here offer a means to characterize the conformational stability of biopharmaceuticals and proteins more generally under cold-temperature stress by the assessment of structural alteration, self-association, and reversibility of each process. This offers an alternative to current ex situ methods that are based on higher temperatures and subsequent extrapolation of the data and interpretations to the cold-temperature regime.

Modelling the effects of cold temperature during the reproductive stage on the yield of chickpea (Cicer arietinum L.)

During the reproductive stage, chilling temperatures and frost reduce the yield of chickpea and limit its adaptation. The adverse effects of chilling temperature and frost in terms of the threshold temperatures, impact of cold duration, and genotype-by-environment-by-management interactions are not well quantified. Crop growth models that predict flowering time and yield under diverse climates can identify combinations of cultivars and sowing time to reduce frost risk in target environments. The Agricultural Production Systems Simulator (APSIM-chickpea) model uses daily temperatures to model basic crop growth but does not include penalties for either frost damage or cold temperatures during flowering and podding stages. Regression analysis overcame this limitation of the model for chickpea crops grown at 95 locations in Australia using 70 years of historic data incorporating three cultivars and three sowing times (early, mid, and late). We modified model parameters to include the effect of soil water on thermal time calculations, which significantly improved the prediction of flowering time. Simulated data, and data from field experiments grown in Australia (2013 to 2019), showed robust predictions for flowering time (n = 29; R2 = 0.97), and grain yield (n = 22; R2 = 0.63–0.70). In addition, we identified threshold cold temperatures that significantly affected predicted yield, and combinations of locations, variety, and sowing time where the overlap between peak cold temperatures and peak flowering was minimal. Our results showed that frost and/or cold temperature–induced yield losses are a major limitation in some unexpected Australian locations, e.g., inland, subtropical latitudes in Queensland. Intermediate sowing maximise yield, as it avoids cold temperature, late heat, and drought stresses potentially limiting yield in early and late sowing respectively.

Response of Sorghum to Cold Stress at Early Developmental Stage

Native and adapted to the semiarid tropical regions of Africa, sorghum (Sorghum bicolor) is generally sensitive to cold temperatures, especially during the early developmental stages. However, there is genetic variability within the existing germplasm in terms of tolerance to low temperatures. The highland regions of Africa possess important sources of germplasm with adaptation to cold stress, since they tend to be cooler than the low land regions. The goals of the study were to evaluate and identify sorghum lines with tolerance to cold temperature stress and make recommendations on varieties that may be planted in the East African highland regions or used in plant breeding programs for cold tolerance. Forty sorghum genotypes were evaluated for emergence, shoot, and root development at seedling stage under controlled environment in growth chambers and in the field. Significant genotypic differences were detected for all evaluated traits. Correlation between controlled environment experiments and field trial results was mostly significant, suggesting that the growth chambers can be used to predict and identify cold-tolerant genotypes. Results showed that emergence and vigor are the best surrogate traits for selecting cold-tolerant genotypes. Using rank summation index, we were able to identify the best cold-tolerant sorghum genotypes (IS 25557, IS 25558, IS 25546, BM6, BM 29, IESV 90042LT, and Cytanobe) that can be used in future breeding programs and enhance adaptation and expansion of sorghum production further into the highland regions of Africa.

Crossability Barriers in Interspecific Hybridization of Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi] with Other Vigna Species

Background: Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi] is a multipurpose grain legume of Mid-Himalayan region mainly cultivated for food, fodder, green manure and has emerged as a good alternative to other pulse crops such as blackgram and greengram which do not flourish in this region due to their susceptibility to cold temperature stress. It is well reported that the nutritional value of ricebean is higher as compared to many other legumes of the Vigna family and has some superior qualities greater than greengram, blackgram and cowpea. It is also resistance to drought, diseases and pests specially the storage pests during growth period and possesses high percentage of seed viability. Despite having all the favourable traits, it is not much popular among the farmers due to the late maturity and indeterminate growth habit. Instead, farmers prefer other crops which fit easily into their cropping pattern and are easy to harvest. A little genetic improvement with respect to maturity and growth habit can revive its cultivation and show great results in its production as a valuable crop. Thus, the present investigation was formulated to introgress desired traits from mash and adzukibean into otherwise high yielding ricebean genotypes using inter-specific hybridization. Methods: The present investigation involves the inter-specific hybridization among three Vigna species viz, ricebean (Vigna umbellata), blackgram (Vigna mungo) and adzukibean (Vigna angularis). In the year 2017, six genotypes of ricebean (RBHP-36, RBHP-38, RBHP-43, RBHP-61, RBHP-107 and RBHP-108) were crossed with two genotypes of blackgram (HimMash-1 and Palampur-93) and one genotype of adzukibean (HPU-51) in glasshouse conditions. Result: The study revealed that successful crosses were possible only between ricebean and blackgram. All the Inter-specific crosses showed very low pod set percentage ranging from 0 -4% and F1 germination percentage ranging from 20-42%. Pod set percentage and pods harvested varied with combinations of two parental cultivars of each species for most of the inter-specific hybrids. The successful pod set was observed in 16 out of 36 inter-specific crosses. Highest crossability was observed in blackgram and ricebean crosses. Crossing of adzukibean with ricebean showed poor or no pod set among the entire cross combinations which are attributed to early embryo abortion and degeneration during embryogenesis.

Transcriptional profiling of MED Bemisia tabaci exposed to thermal stress and verification of HSP70 expression

AbstractTemperature changes impact agricultural production and also influence the behavior and community structure of many insect species. Bemisia tabaci, is an invasive and destructive pest with at least 44 cryptic species and occurring in over 100 countries and regions. In this study, transcriptional profiling was used to evaluate the response of the Mediterranean (MED) cryptic species B. tabaci exposed to cold and hot temperature stress. In response to cold stress, 3,024 unigenes were differentially expressed and mapped to 39 Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathways. A total of 4,437 unigenes were differentially expressed during heat stress, and these represented 18 KEGG enrichment pathways. Quantitative RT‐PCR was used to determine the relative expression level of the 11 HSP70 fragments; these were significantly up‐regulated during high temperature stress relative to the control group that was maintained at 26°C. In conclusion, the transcriptome data indicated that B. tabaci responds to thermal stress via multiple genes and networks. Furthermore, HSP70 plays an important role in stress tolerance of the MED B. tabaci, especially during heat stress.

Insights into the similarities and differences of whiteleg shrimp pre-soaked with sodium tripolyphosphate and sodium trimetaphosphate during frozen storage

In this study, similarities and differences of sodium tripolyphosphate (STPP) and sodium trimetaphosphate (STMP) pre-soaking on the stability of muscle proteins in shrimp were investigated during 12 weeks of frozen storage (−30 °C). The physicochemical analysis indicated significant improvements in the WHC, springiness, chewiness, and thermal stability of STPP and STMP pre-soaked samples when compared to the control. Interestingly, STMP pre-soaking showed better cryoprotective effects than the STPP treatment when the storage period reached the end of the 12 weeks. Furthermore, the label-free based proteomics results indicated that 62 upregulated differentially abundant proteins (DAPs) were detected in STMP when compared to STPP. These identified DAPs specifically included 40S ribosomal proteins, actin-related proteins, heat shock proteins, myosin heavy chain, and tubulin beta chain. Additionally, the gene ontology (GO) and eukaryotic clusters of orthologous group (KOG) analyses verified that the incorporation of STMP molecules enhanced the resistance of cytoskeleton proteins to cold-temperature stress.

薄毛海绵杜鹃结实和萌发特性随环境的变化

PDF HTML阅读 XML下载 导出引用 引用提醒 薄毛海绵杜鹃结实和萌发特性随环境的变化 DOI: 10.5846/stxb201905231062 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31860123，31560153，31260147）；西藏农牧学院2016年生态学科建设项目 Variation of fruiting and germination characteristics of Rhododendron aganniphum var. schiaopeplum with environmental factors Author: Affiliation: Fund Project: The National Natural Science Foundation of China (31560123，31860153，31260147）、 2016 Ecological Discipline Construction Project of Tibet Agriculture and Husbandry University 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:选择青藏高原东南林线地区优势植物薄毛海绵杜鹃为对象，研究薄毛海绵杜鹃结实特性和萌发特性随海拔（4183-4673 m）、坡度、坡向等环境梯度的变化规律。对比了不同环境条件下薄毛海绵杜鹃果实的长、宽、重量、单果种子数、种子千粒重等结实特性；并测试了不同环境所产种子的萌发对温度和光照的响应。结果表明：（1）在高海拔低温胁迫环境下，薄毛海绵杜鹃的生殖投入加大，果实大且质量重，种子数量多但质量轻；（2）坡向是影响单果种子数量的主要环境因子，阴坡单果种子数显著大于阳坡，生活在阴坡的薄毛海绵杜鹃的繁衍能力更强；（3）较高和较低土壤湿度都会影响薄毛海绵杜鹃的种子质量，中等土壤湿度（28.3%-32.5%）薄毛海绵杜鹃种子萌发能力最强；（4）薄毛海绵杜鹃的种子是需光性种子，在黑暗条件下几乎不萌发；（5）在光照条件下，温度对种子萌发率和萌发速率有显著影响，高温（25/5℃）有助于提高萌发率并促使萌发进程显著提前。研究揭示了不同海拔薄毛海绵杜鹃结实和萌发特性与环境之间的关系，为薄毛海绵杜鹃的种质资源保护和气候变化背景下藏东南林线动态预测提供了基础资料。 Abstract:Fruiting and germination characteristics of the dominant plant species Rhododendron aganniphum var. schiaopeplum and their variation along the environmental gradients such as altitude (4183-4673 m), slope and aspect were studied at the alpine treeline ecotone on the southeastern Tibetan Plateau. The fruiting characteristics including fruit length, width, weight, seed number per capsule and 1000-seed weight of R. aganniphum var. schiaopeplum from different habitats were measured and compared, and the responses of seed germination to temperature and light were tested. The results showed that: (1) as cold-temperature stress increasing at higher altitude, the reproductive input of R. aganniphum var. schiaopeplum increased, with larger and heavier fruits, more seed number per capsule but smaller seeds than that from other environments; (2) slop aspect was the main factor affecting seed number per capsule with significantly larger seed number per fruit on the shady slope than that on the sunny slope, indicating a better reproductive ability on the shady slope; (3) seeds of the population in moderate soil moisture conditions (28.3%-32.5%) showed highest germination ability; (4) seeds of R. aganniphum var. schiaopeplum are photosensitive and cannot germinate in darkness; (5) in light conditions, germination percentage and rate are significantly affected by temperature, and the highest germination percentage and the most speedy germination showed at 25/5 ℃. This study investigated the relationship between fruiting and germination characteristics of R. aganniphum var. schiaopeplum and their habitat conditions, which provides basic data for the germplasm conservation and the dynamic prediction of the tree-line on the southeastern Tibetan Plateau in the context of climate change. 参考文献 相似文献 引证文献