Статьи журнала - Журнал стресс-физиологии и биохимии
Все статьи: 984
Статья научная
In this study we compare a few physiological parameters of a salt sensitive (Jaya) and salt resistant (Korgut) rice varieties to understand mechanism of salt tolerance. Jaya, high yielding salt-sensitive rice (Oryza sativa) variety, and Korgut, a 100% salt-tolerant rice variety, were grown for 15 days in vermiculite irrigated with NaCl solutions of 0 – 200 mmolL-1 prepared in Hoagland’s solution (pH 6.5). It was observed that initial fluorescence (F0) value increased, and the maximal fluorescence ratio (Fm) decreased in Jaya; however, the Korgut variety maintains the F0 and Fm value without much significant variation as NaCl increased. On the other hand, Actual efficiency (ΦPSII) significantly decreased in Jaya showed slightly decreased at 200 mmolL-1 NaCl treatment. The polypeptide composition of the thylakoid membrane decreases after NaCl treatment in the Jaya variety, but it's maintained in the Korgut variety. Photo-inactivation of PSII in Jaya includes the loss of the D1 and D2, (32-34 kDa) protein, probably from greater photosynthetic damage caused by salinity stress; Korgut is not showing alternation of the same protein, and it's maintained the greater photosynthetic. In Jaya, most prominently, the dramatic decline of the 47-kDa chlorophyll protein (CP), 17-kDa (F0), and (10kDa) OEC protein vice versa in Korgut. The decreased in 47-kDa, and 23kDa proteins in Jaya lead to the decreased energy transfer from the light-harvesting antenna to PSII due to the marked alterations in the composition of thylakoid membrane proteins. The most important of changes in Korgut indicate maintained chlorophyll fluoresces without altering the thylakoid membrane protein towards adaptation to salinity. These findings can be translated into efforts to develop more salt-tolerant cultivars and exhaust the possibilities of using saline soils.
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Effect of NaCl priming duration and concentration on germination behavior of Tunisian safflower
Статья научная
Priming is an effective technique that improves germination of several crop species. That's why; this study was carried in order to evaluate the effect of NaCl seed priming techniques on germination and early growth of safflower (Carthamus tinctorius L.). Safflower seeds were primed with four concentrations of NaCl as priming media (5, 10, 15 and 20 g/l) for 12, 24 and 36 hours. Results indicated that different priming concentrations and duration have significant on total germination percentage, mean germination time, germination index and coefficient of velocity of safflower seeds. It was also observed that 12 h priming duration had the most effect on studied traits as 5 g/l priming concentration treatment. In general, primed seeds showed better performance than control (non primed seeds) in all studied parameters.
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Статья научная
Salinity is one major problem of increasing production in crop growing areas throughout the world. The objective of this research was to evaluate the effect of NaCl priming on seed germination of Tunisian fenugreek ( Trigonella foenum-graecum L.) under salinity conditions. Seeds of fenugreek were primed with NaCl (4g/l) for 36 h in continuous 25°C. Experimental factors were included 2 priming treatments (NaCl and non-priming as control) and five salinity solution (4,6,8,10 and 12 gl -1). Results showed that seed priming increased final germination percentage, germination speed and radicle length over the non-primed treatment. At the lowest levels of salinity, there were no notable differences between primed and non-primed seeds, but with increasing salinity levels, primed seeds showed the better performance than non-primed seeds. These results indicated that NaCl priming significantly improved seed performance under salinity conditions.
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Effect of PEG-6000 imposed water deficit on chlorophyll metabolism in maize leaves
Статья научная
Drought stress is one of the major abiotic constraint limiting plant growth and productivity world wide. The current study was undertaken with the aim to investigate the effect of water deficit imposed by PEG-6000, on chlorophyll metabolism in maize leaves to work out the mechanistic details. Leaf segments prepared from primary leaves of etiolated maize seedlings were treated with varying concentrations of polyethylene glycol-6000 (PEG-6000; w/v- 5%, 10%, 20%, 30%) in continuous light of intensity 40 Wm -2 at 26±2 °C for 24 h in light chamber. The results demonstrate a concentration dependent decline in chlorophyll content with increasing concentration of polyethylene glycol-6000 (PEG-6000). Reduction in chlorophyll ‘a’ level was to a greater extent than the chlorophyll ‘b’. The RNA content decreased in a concentration dependent manner with PEG, however, proline content increased significantly. Relative water content decreased significantly with the supply of 30% PEG only. A substantial decrease in chlorophyll synthesis due to significant reduction in ALA content and ALAD activity, with no change in chlorophyllase activity with the supply of PEG suggests that water deficit affects chlorophyll formation rather than its degradation.
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Статья научная
Background: Epilepsy is a Neurological disease. It interferes with the brain's normal electrochemical functions. Similar to a seizure, Epilepsy is an indication of irregular brain activity.
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Effect of Stress on Structural Behavior of Periplasmic Membrane In Pathogenic Organism
Статья научная
Microorganisms have an assortment of evolutionary adaptations and physiological advancement mechanism which permit them to survive and stay dynamic in face of environmental stress. The examination propose that all the more proficiently coordinating microbial ecology into biological system nature will require more complete integration of microbial physiological ecology, population biology and process ecology. Microorganisms also have genomic and metabolic plasticity to adapt the numerous stressful conditions they come across during their life. They give a remarkable illustration of adaptation to the most diverse environments. There is still plenty to learn on how pathogens react to host imposed stresses, how environmental microorganisms become acclimated to so viably to the continually changing environments, how metabolic changes at last shape their genome and how all the above can be exploited to our advantage, for example preventing food to spoil, improving food safety, performing industrial synthesis with nominal or no contamination. The revealing insight into fundamental parts of microbial reactions to stress can have commonsense consequences in irrelevant fields, for instance in the fix of human sicknesses. The aim is additionally to provide a strong interdisciplinary climate which will give a gathering to the flow of new various thoughts for better understanding microbial physiology under stress. There are a few stress to organisms include osmotic stress, oxidative stress, pH stress, thermal stress, periplasmic stress, and nutrient and starvation stresses. Environmental stresses are commonly active during the cycle of microbial fermentation and have critical impact on microbial physiology. Microorganisms have built up a progression of systems to oppose ecological anxieties. They keep up the honesty and smoothness of cell films by tweaking their configuration and composition, the penetrability and activities of carriers are changed in accordance with control nutrient transport and ion exchange.
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Статья научная
Rheum emodi is a rare medicinal herb in the Himalayan region due to its medicinal cum aromatic properties it is highly over-exploited from nature. Complete Randomized Design was executed and study aimed to understand the effect of different concentration of Lead and Cadmium in growth and biochemical parameters of Rheum emodi (Wall. Ex Meissn) as comparison to control. In plants, heavy metals Quantity were analyzed to show their effects on the animal and human beings who consume them as such or their derived products. In this study, encouraging results were obtained which favoured maximum (53.33%; p<0.05) mean germination in control and minimum in 1.5g concentration in both case of Lead and Cadmium treatment.
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Effect of abiotic stresses on Histidine Kinases gene expression in Zea mays L. cv. Sc. 704
Статья научная
UV-B radiation and osmotic stress (like drought and salinity) have a significant effect on physiology, morphology, biochemistry and molecular biology. To cope with such stimuli, plants must be able to effectively sense, respond to and adapt to changes in their biological activities. Hence, signal transduction pathways play important role in response to environmental stimuli. In this study, the expression of three Histidine Kinases including ZmHK1, ZmHK2 and ZmHK3a was studied in maize plants exposed to 8 days drought, salinity and UV-B stresses applying transcript approach. The semi-quantitative RT-PCR analyses of ZmHKs showed up-regulation of ZmHK1 and ZmHK3a genes after 8 days exposure to applied stresses except salinity in leaves, although, their regulation was more prominent during drought stress. Astonishingly, exposure to these stresses showed down-regulation of all genes in maize roots. However, the ZmHK1 behavior was quite different from two other homologues and showed up-regulation in combined stresses. We suggest that ZmHK1 and ZmHK3a, as cytokinin transmembrane receptors, sense osmolarity changes in cells caused by dehydration. Our data supports the involvement of ZmHK homologues under these stresses in maize and provides a gene expression dynamics during the stress which will be valuable for further studies of the molecular mechanisms of stress tolerance in maize.
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Effect of acute hypoxia on the functional state of erythrocytes and hemoglobin in black scorpionfish
Статья научная
In the present work the influence of hypoxia on black scorpionfish ( Scorpaena porcus ) nucleated red blood cells has been studied at in vivo (whole blood) and in vitro (cell suspension) experiments. Experiments were conducted in the range of oxygen concentration 0,3-8,5 mg О2 l-1, water temperature 14-16 оС, and the duration of exposure period was 4 h. Deep hypoxia (less than 2 mgО2 l-1) caused hemoglobin transition to a ferry-form (MtHb), and the most substantial increase of MtHb concentration was observed at severe hypoxic conditions (less than 1 mg О2 l-1). The highest MtHb level observed was 19-32 %. The results of in vivo and in vitro experimental series were similar, indicating that mechanisms involved in MtHb formation occur within cells and are not associated with organismic responses to oxygen deficiency. Moderate hypoxia (oxygen concentration more than 2 mg О2 l-1) did not cause hemoglobin transformation. MtHb formation did not influence the level of reactive oxygen species (DCF-DA fluorescence) and the integrity of cellular membrane (double staining with SYBR Green I and Propidium iodide) in red blood cells. The level of dead cells in control and experimental groups did not differ, indicating that responses observed were in the range of physiological norm.
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Статья научная
Agrobacterium tumefaciens infection and antibiotic wash are the critical steps of Agrobacterium mediated plant transformation procedure, most time responsible for lower transformation efficiency due to necrosis and phytotoxicity caused by biotic stress of Agrobacterium and abiotic stress by antibiotics respectively. Ammi majus Egyptian origin medicinal plant and Pearl millet cereal grain crop were studied for their stress responses to Agrobacterium mediated transformation (AMT). Agrobacterium strains LBA4404 (O.D.=0.6-0.8) and EHA105 (O.D.=0.2-0.4) were used for transformation experiments to infect calli of Ammi majus and embryogenic calli of Pearl millet respectively. Incase of antibiotic wash, Cefotaxime 500 mg L -1 was used for LBA4404 infected Ammi majus calli and Timentin 300 mg L -1 was used for EHA105 infected embryogenic calli of Pearl millet. Effects of Agrobacterium infection, antibiotic and NaOCl washes on Agrobacterium removal and both explants physiological changes during transformation experimental procedures were studied. At the end of the experiments explants survival efficiency of Ammi majus and pearl millet were 8% and 5% respectively. Biotic and abiotic stress factors responsible for lower efficiency were investigated with various other factors and strategies were discussed which are need to be considered for higher transformation events and target tissue survival.
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Статья научная
In order to investigate the ability of constant temperature and thermoregulation in Apodemus chevrieri, body temperature and rest metabolic rate (RMR) were measured during postnatal development (1～42 day) when the A. chevrieri exposed different ambient temperature. The result showed that: body temperature and RMR of pups in A. chevrieri increased according to the increase of ambient temperature during 1 day to 7 day, showed character of poikilotherms; body temperature of pups were lower in low temperature(5 oC and 10 oC), relatively and RMR significant increased when day age is 14 day, it indicated that the pups showed a certain degree of thermoregulation in this phase. Its thermoregulation ability developed quickly during 7 day to 14 day. RMR of pups was extreme significantly higher in low temperature than that in other temperature when day age was 21 day, it showed that the pups had some thermoregulation to low temperature stimulation. The RMR of pups was showed increasing trend in high temperature(35 oC) when 28 day; when day age was 35 day and 42 day, the thermal neutral zone were 22.5 to 30 oC and approaching its adult level. All of these results indicated that pups of A. chevrieri in the different growing period had different thermogenesis and energy allocation to maintain stable to body temperature, thermogenesis was weaker in the early phase of postnatal development, most of energy is used to its growth. After pups were weaned, the ability of constant temperature and thermoregulation developed quickly to adjust variations of environment during postnatal development.
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Статья научная
In the natural environment, the life activity of organisms takes place under conditions of stable daily, lunar and annual light cycles. However, human activities aimed at creating comfortable conditions for people have resulted in light becoming one of the factors of anthropogenic environmental pollution. Artificial lighting at night can cause physiological and behavioural changes and disturbances in aquatic organisms, affecting their vital functions. Fish are one of the groups of aquatic organisms that are most susceptible to the influence of light at night, largely due to the anatomical structure of their eyes. The aim of this work was to test whether keeping Phoxinus phoxinus (Linnaeus, 1758) under constant light exposure promotes the growth of inflammatory processes in them, and also to study whether lighting at night affects oxygen consumption. Experiments showed that the oxygen consumption of P. phoxinus increased statistically significantly (p = 0.04303) at night with light compared to night without light. In an experiment in which blood cell counts were performed, the results showed a statistically significant increase in leukocytes (p = 0.01506) in the third experimental group of four kept under constant artificial light for 17 days. Based on the results of our study, it has been confirmed that keeping fish under abnormal light conditions, i.e. using different sources of artificial light at night near water bodies, can lead to physiological changes that can have a negative impact on the life of organisms. In fish, the level of oxygen consumption increases, indicating an increase in the level of metabolism, which in turn affects the growth and formation of organisms, causing a decrease in the intensity of various physiological processes such as feeding and reproduction. There is also an increase in the level of leukocytes, which indicates an increase in inflammatory processes in the organisms, which can lead to a decrease in immune function and, as a result, the susceptibility of fish to various diseases.
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Effect of artificial photoperiod on the blood cell indices of the catfish, Clarias batrachus
Статья научная
The present study is aimed to assess the influence of artificial photoperiod on the blood cell indices of an Indian catfish, Clarias batrachus(Linn.). Blood samples taken from adult fishes exposed to artificial photoperiod of 24L:0D and 0L:24D for a short period of 24 hrs, were analyzed for total RBC, total WBC, differential leukocyte count (DLC) and some physiological variables - glucose and chloride. The total RBC and WBC counts were unaffected by both the artificial photoperiod regimes. However, lymphopenia (p
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Effect of biotic stress on vitamins and nutrients of Ficus palmata
Статья научная
Biotic stress mediated effects on amount of tocopherol, ascorbic acid and nutrients like sodium and potassium ion of Ficus palmata were investigated in the current study. Present study revealed that the amount of tocopherol in healthy leaf was greater than diseased leaf. However, the amount of ascorbic acid in disease leaf (0.406±0.0108) was more as compare to healthy leaf (0.447±0.0386) of F. palmata . The amount of tocopherol in healthy leaf was 2.0915±0.4188 and in diseased leaf it was 1.786±0.1383. On the other hand, the amount of sodium in both healthy and diseased leaf was similar (1.333±0.333).The amount of potassium in healthy leaf was more (42.00±2.081) as compared to the diseased leaf (33.33±10.929). Greater the amount of ascorbic acid and tocopherol in plants more will be radicle scavenging activity and also helpful in pharmacological industry, drug production and health care.
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Статья научная
The objectives of the study are to analyze the physiological changes, biochemical alterations and attenuation of nickel toxicity effects in wheat seedlings under combined applications of Ni ions, metal chelators (EDTA/Citric Acid) and metal ions (Zn2+ /Mg2+). Wheat (Triticum aestivum L cv UP262) seedlings were grown hydroponically using different concentrations of Ni up to 7 days along with chelators and metal ions for study. The seedling growth was maximum with NiCl2-Zn2+ (100µM) and minimum with NiCl2-EDTA (100µM) treatments. Total chlorophyll content was maximum in the seedlings treated with NiCl2-Zn2+ (100µM) and minimum in NiCl2-EDTA (100µM) treatments. NiCl2-EDTA (100µM) showed less Fo and Fm values and therefore, a trend in the decrease in OJIP transient indicates the maximum alteration of photochemical activity of PS-II in presence of NiCl2-EDTA (100µM) treatment. Similar observation was found by NiCl2 -EDTA (200µM) treatment where Fo and Fm values were noted to decline. High nickel content in roots of the seedlings was noted as compared to shoots.
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Статья научная
In this work, we studied the influence of cold acclimation (first stage - 8 °С/2 °С for 10 days and second stage - subsequence action of -2 °С for 10 days) and deacclimation (10 °С for 2 days) on the content of soluble carbohydrates and the synthesis of dehydrins in leaves of two variety of winter wheat ( Triticum aestivum L.) that are differed in frost resistance. It is detected that the winter wheat of Irkutskaya variety and Pamyat variety are differed in the dynamics of accumulation and content of dehydrins in leaves. The most frost resistant Irkutskaya is characterized by a higher content of dehydrins in the leaves during acclimation and deacclimation, compared with the less frost resistant Pamyat.
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Статья научная
The aim of the present study was to examine the energy strategy in response to the cold temperature and food shortage. The survival rate, body mass, body fat content, serum leptin levels, basal metabolic rate (BMR) and nonshivering thermogenesis (NST) as well as masses and the morphology of visceral organs and the digestive tract were measured in Eothenomys miletus that was subjected to the cold temperature (5°C) and food restriction (80% of ad libitum food intake). The results showed that body mass, body fat content, serum leptin levels, brown adipose tissue (BAT) mass and dry mass of digestive tract in cold and food restriction group were lower than those in control group. In contrasts, BMR and NST in cold and food restriction group was significantly higher relative to control group. The rate of survival was 18.18% in E. miletus during cold and food restriction after 4 weeks acclimation. In addition, serum leptin levels were positively correlated with body mass and body fat content, and negatively correlated with BMR and NST. These results suggested that E. miletus apply physiological adjustments to adapt cold and food lacking external environment by reducing body mass, body fat content, and increasing energy metabolism. However, energy intake is insufficient to compensate for the increase in energy requirement due to cold, led to body mass decreased and mortality rate increased. Moreover, serum leptin may acts as a fat signals, and may be involved in the regulation of energy balance and body mass in E. miletus under the cold temperature and food restriction.
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Статья научная
Effect of controlled irrigation in physiological and biometric characteristics in teak seedlings is monitored at Forestry College in Kerala, India. Six month old seedlings of Teak (Tectona grandis L. f.) were raised in polybags. Irrigation was done once in a week. Daily evapotranspiration was calculated and treatments IW/ET=1, IW/ET=0.6, IW/ET=0.3 were irrigated with 100, 60 and 30 per cent of cumulative evapotranspiration. A control without irrigation (IW/ET=0) was also maintained. Physiological as well as biometric observations were carried out at regular intervals. Canopy air temperature difference (CATD) was measured using a hand held infrared thermometer and it was observed that seedlings from well watered treatments (IW/ET=1 and 0.6) showed negative CATD whereas treatments IW/ET=0.3 and IW/ET=0 showed positive CATD throughout the growing period. Seedlings in the treatment IW/ET= 0 and 0.3 showed a significant reduction in relative chlorophyll content, seedling height, collar diameter, number of leaves, total dry weight and relative growth rate whereas in IW/ET=1 and 0.6 these parameters were higher and there was no significant difference observed between these two well watered treatment. In the case of root shoot length ratio and root shoot biomass ratio IW/ET=0 was superior over other three treatments.
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Статья научная
The present study was aimed to examine the influence of BRs on seed germination and seedling growth in Gossypium hirsutumL. Var Svpr 2 Vigna mungo (L.) Hepper Var T9. application of BRs on seed germination of Gossypium hirsutum the rate of germination considerably with varied percentage from 60.4 to 99. Vigna mungoseed also showed the varied percentage of germination from 56.8 to 80.1. Both the plants exhibited high percentage of vegetative growth such as shoot length, fresh weight, dry weight and leaf area on 3% of BR supplementation. The amount of chlorophyll a, b and total chlorophyll increased under BR treatments. Among the concentration, 3% BRs caused maximum effect than the other tested concentrations. High percentage of starch 53% and 31 % was observed in Gossypiumand Vignamungorespectively. The results of the present study shows that 3% BRs promotes the growth rate of Gossypium hirsutumL. Var Svpr 2 and Vigna mungo (L.) Hepper Var. T9. The results of the present study supplemented to the previous observations and practical utilization of the new steroidal group of phytohormones for large scale production of the economically important crops Gossypium hirsutumL. Var Svpr 2 and Vigna mungo (L.) Hepper Var. T9.
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