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Журнал стресс-физиологии и биохимии / Journal of Stress Physiology & Biochemistry
2012. — Выпуск 4
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The study was focused on characteristics of gluten, protein and aminoacids content in wheat grain under the impact of microbe preparations including bacteria of Azotobacter and Bacillus geni, which inhabit plant rhizosphere. The increase of aminoacids leveland particularly the level of essential aminoacids in wheat grain under bacterization was demonstrated, this fact accounting for the quality of grain as an important protein source. Increase of aminoacids content with the use of biopreparations on low-fertile soil ensures acquisition of biologically valuable grain with the decrease of mineral fertilizers dosage and emphasizes the role of biopreparations in the production of ecologically pure high quality products. The latter is due to introduction of environmentally safe agricultural methods.
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Background, the context and purpose of the study: Pendimethalin [N-(1-ethyl propyl)-2, 6-dinitro-3, 4 xylidine] is one of the most commonly used herbicides. It induces harmful effect on non-target plants besides controlling the weed emergence. Salicylic acid (SA) plays an important role in abiotic stress tolerance. Present study was to assess the comparative efficacy of SA in combination with different concentrations of pendimethalin on black gram (Vigna mungo). The seeds of test plant were treated with field relevant concentrations (2, 5 and 10 ppm) of pendimethalin (P) and in combination with SA (0.5 mM) to observe effect of SA against herbicide toxicity. Experiment was performed in petri dish as well as in pot culture. The toxic effect of pendimethalin and SA on seed germination (SG), radicle length (RL) and mitotic index (MI) was evaluated in petri dish culture. Seedling height, pigments, protein, sugar contents and lipid peroxidation (LP) of 15 days old seedling were measured in pot culture. Total antioxidants (TA) were monitored as plant defence against oxidative stress. Results, the main findings: Results showed that SG and seedling growth of Vigna mungo decreased under P1, P2 and P3 treatments. RL and MI were also reduced significantly (p<0.05) in treatments with herbicide and reduction was more pronounced in P3 treatment. A slight increase of SG and seedling growth was observed in P2 treatment compared to P1. Herbicide treatment remarkably declined pigment, protein and sugar contents of the seedlings when compared with control. TA and malondialdehyde (MDA) content increase significantly under pendimethalin treated seedlings. Combined treatment (P+SA) elevated growth of the seedlings. As a consequence of herbicidal stress, SA enhanced SG, RL, MI, pigment, protein and sugar content significantly. Under combined treatments, LP and TA were decreased when compared with pendimethalin treatment. Conclusions, brief summary and potential implications: SA enhanced growth of Vigna mungo not only in combination with pendimethalin but also in treatment with SA alone as compared to control. Thus the results reveal, the role of SA in protection of Vigna mungo against herbicidal stress is apparent. The results are discussed in light of recent information.
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Eothenomys miletus and Apodemus chevrieri are typical species of small mammals inhabiting in Hengduan mountains region. The characteristics of thermoregulation and thermogenesis of two mammals were measured to search their physiological and ecological characteristics of adaptations to this region in different seasons. All results indicated: the body weight of E. miletus and A. chevrieri in summer was separately 47.29±0.73g, 32.74±0.54g, and their body weight in winter was separately 39.28±0.61g, 31.70±0.76g; the thermal neutral zones(TNZ) of E. miletus and A. chevrieri in summer were separately 25～32.5 oC and 25～30 oC, and their TNZ in winter were all of 22.5～27.5oC; their basal metabolic rates(BMR) in summer were respectively 3.76± 0.07ml O2/g.h, 4.58±0.09mlO2/g.h, and their BMR in winter were respectively 4.46±0.04mlO2/g.h, 5.23±0.01mlO2/g.h; their maximum nonoshivering thermogenesis(NST) in summer was respectively 5.70±0.18mlO2/g.h, 7.12±0.31mlO2/g.h, and their NST in winter was respectively 6.67±0.05mlO2/g.h, 7.42±0.04mlO2/g.h; their NST scope(NST/BMR) in summer was separately 1.52±0.05, 1.46±0.04, and their NST scope in winter was separately 1.49±0.01, 1.42±0.01. Their thermogenic characteristics and thermoregulatory styles possibly reflected features of small rodents in Hengduan mountains region which have lower body temperatures and NST scope, higher BMR, Cm and NST and could keep their body temperatures stable in narrower ambient temperatures comparing with other rodents. Body temperature, Cm BMR and NST of A. chevrieri were higher than these of E. miletus. A. chevrieri could keep body temperature stable in a wider range of ambient temperatures than E. miletus. NST scope of E. miletus was higher than it of A. chevrieri. Their TNZ and the ambient temperature range in which they could keep C stable in winter were narrower than these indexes in summer. The body temperature and body weight in winter were lower comparing with the summer. The BMR, F-value and NSTmax in winter were significantly higher than the summer. The TNZ in winter was shifted to the lower ambient temperature comparing with the summer.
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Photoperiod effect on Growth parameters and cannibalism of Clarias gariepinus have been well documented in resent past, but little is known about the response of other biological parameters such as, Condition factor, Shooters composition, Body colouration and Blood glucose of this important tropical fish species to different photoperiods, therefore the present study was designed to evaluate these responses of the African catfish to 24 hours of light (00D:24L), 24 hours of darkness (24D: 00L) and 12 hour light / 12 hours darkness (12D: 12L). The six weeks experiment observed significant differences (P<0.05) in weight gain of the fish reared at the different photoperiods with the highest value of 92.20g+1.10 obtained in fishes reared under a photoperiod of twenty-four hours of darkness (24D: 00L) compared to those reared under a photoperiod of twelve hours of light and twelve hours of darkness (12D: 12L) which had 69.80g+2.50 and the least weight gain of 59.50g+8.2 was obtained under a twenty four hours of light (00D: 24L) photoperiod. Despite the stress induced by light which affected the weight gain of the fish, condition factor of the fishes in the different photoperiods did not vary significantly (P>0.05) at the end of the experiment and were Significantly lower than value obtained at the start of the experiment, Shooters composition was highest in 00D:24L (41.5% i.e. 27 of 65) leading to high mortality (13.33%) due to cannibalism compared to 12D: 12L (Shooters =15.27% i.e. 11 of 72, Mortality= 4%) and 24D: 00L (Shooters=5.33% i.e. 4 of 75, Mortality= 0%) photoperiod. More so, 93.33% (70 of 75) of fish in the dark phase (24D: 00L) exhibited Deep shiny black body colouration, while 6.67% (5 of 75) was observed of Normal fish colouration. However the fishes in the 00D: 24L photoperiod were observed to be predominantly Lighter skin colouration, (80% i.e. 52 of 65= lighter colouration, 18.46% i.e. 12 of 65= Normal skin coloration and 1.53 i.e. 1 of 65= Deep black body colouration) while 12D: 12L were of Normal skin colouration (100% Normal skin colouration), also blood glucose was observed to increase as the light hours increased (P<0.05) with 24D: 00L photoperiod having the highest blood glucose level of 5.7+0.5, while those in 12D: 12L had 4.4+0.3 and 24D: 00L had the least value of 3.9+0.1. This study therefore establishes the fact that photoperiod may have no effect on the condition factor of African catfish, while higher shooters composition is highlighted as one of the causes of increased mortality and could be reduced to a large extent with reduced light phase therefore enhancing higher survival, also the use of blood glucose as an indicator of stress in fish was justified in the present study.
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Soil contamination with heavy metals has become a worldwide problem, leading to losses in agricultural yield and hazardous health effects as they enter the food chain. Nickel as an essential trace element, affect a number of biochemical and physiological processes in plants in toxic levels. The most common symptoms are chlorosis, and inhibited photosynthesis and respiration. Zea mays seeds were germinated and cultured on nutrient solution with nickel concentrations of 50-200 μmol for a period of two weeks. Studied physiological makers included photosynthetic pigments content, the rate of Hill reaction, K+ efflux and carbohydrate leakage from the roots to the external solution and cell death as a Ni-induced membrane damage. By increasing Ni concentration up to 100 μmol, the content of chlorophyll a increased, but decreased at 200 μmol Ni. No significant changes in chlorophyll b and carotinoids content observed. The rate of Hill reaction as an ability of chlorophyll a in the reaction center of PSII680 to split water, decreased by increasing Ni concentration. Different concentrations of nickel increased the K+ efflux and sugar leakage from roots to the culture and the cell death of root tips. The present results suggested that the disruption of photosynthesis by Ni cannot be attributed to any single factor and appears to result from its combined effects on chloroplast structure, chlorophyll content and photosynthetic protein complexes and treatment with different levels of nickel may induce structural damage and alterations in membrane properties by generation of reactive oxygen species.
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The study was focused on morphological and physiological peculiarities of pea plants with various nodulation ability under the infection by Rhizobium leguminosarum. Microscopic studies identified distinct features in formation of root nodules in different pea mutants. We revealed differences in the content of indole-acetic acid (IAA) in mutants in the root zones differing by sensibility to R. leguminosarum. It was concluded that hormonal system of plants plays an important role in control of nodulation process, and emergence of mutations inducing disturbance of nodule-forming ability apparently depends on root hormonal status, in particular, IAA concentration ensuring both formation of nodule meristem and further organogenesis of the nodule.
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The aim of the investigation was to evaluate oxidative stress in sheep affected with peste des petits ruminants (PPR). Oxidative stress in the affected sheep was evaluated by determining various serum biomarkers viz. vitamin A, vitamin C, vitamin E, glutathione, catalase, superoxide dismutase, glutathione reductase and xanthine oxidase, the mean values of which were 1.70±0.07 µmol L-1, 13.00± 0.10 µmol L-1, 2.25 ±0.07 µmol L-1, 3.10 ±0.06 µmol L-1, 140.00 ±8.00 kU L-1 , 294.22 ±9.91 kU L-1 , 6.99± 0.05 kU L-1 and 100.10 ±3.00 m U L-1, respectively. The levels of vitamins A, C, E and glutathione decreased significantly (p≤0.05) and the serum catalase, superoxide dismutase, glutathione reductase and xanthine oxidase activities increased significantly (p≤0.05) in affected sheep as compared to that in healthy ones. On the basis of the altered levels of serum biomarkers of oxidative stress it was concluded that the animals affected with PPR developed oxidative stress. The findings suggested the relevance of periodic assessment of oxidative status in ruminants for healthier management through supplementation of proper antioxidants as supportive treatment in PPR and in healthy in-contact animals.
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The ameliorative effect of salicylic acid (SA) on cadmium (Cd) toxicity in sunflower plants was studied by investigating plant growth and fatty acid composition. Sunflower plants in two leaves stage were exposed to CdCl2 treatment (0, 50,100,150 and 200 µM) and then were treated with salicylic acid (0, 250 and 500 µM) as foliage spraying. One week after the last salicylic acid treatment,plants were harvested and growth parameters were measured . Oil of leaf was extracted in a Soxhlet system and fatty acid composition were measured by gas chromatography(GC). Statistical analyses showed excess Cd reduced growth parameters (fresh weight and length of stems and roots, fresh weight and number of leaves)and SA increased them compared with the control. Maximum reduction in these parameters was at 200 µmol Cd and 0µmol of SA. Cd caused a shift in fatty acids composition, resulting in a lower degree of their unsaturation and an increase in saturated fatty acids in sunflower leaves,whereas SA improved them. SA, particularly increased the percentage of linolenic acid and lowered that of palmitic acid by the same proportion. These results suggest membrane integrity due to lipids est that SA could be used as a potential growth regulator and a stabilizer of protection of cadmium-induced oxidative stress to improve plant resistance to Cd stress.
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The thermogenic mechanisms were measured in the two small rodents, Eothenomys milletus and Apodemus chevrieri in Hengduan mountain region during cold exposure. The main results were as follows: 1. RMR and NST incredsed 68.34%, 36.34% during the cold exposure in E.miletus, RMR and NST incredsed 32.84%, 56.17% during the cold exposure in A. chevrieri, respectively. 2. During cold exposure, total protein content in liver, the total protein content(TP) and mitochodrnal protein content(MP) in brown adipose tissue (BAT), the content of uncoupling protein (UCP1) were increased in E.miletus, which increased 18.66%, 25.18%, 70.01%, 99.39%, respectively. Total protein content in liver, the total protein content(TP) and mitochodrnal protein content(MP) in brown adipose tissue (BAT), the content of uncoupling protein (UCP1) were increased in A. chevrieri, which increased 18.11%, 33.29%, 34.51%,235.95%, respectively. All of the results indicated that the mechanism of heat production for adaptative changes was similar in two rodents, but it showed different increased amplitude of heat production, it may considered that the difference of heat production was related to origin of species and inhabitats.
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This paper is the first in a series reporting a study on the effects of different concentrations of insecticide, Endosulfan (0-600ppm) was premeditated on 5th day after insecticide exposure with respect to growth rate, pigment composition and photosynthetic activity of Azolla microphylla under laboratory conditions which become non-target organism in the rice fields. Endosulfan inhibited the relative growth rate, pigment content and photosynthetic O2 evolution. Phycocyanin was main target followed by carotenoid and total chlorophyll. Significant increase in pigment, flavonoid and Anthocyanin was noticed after six days of treatment. In contrast to the photosynthetic activity, the rate of respiration in Azolla microphylla was increased significantly. Our results show that Endosulfan at normally recommended field rates and intervals are seldom deleterious to the beneficial and Eco friendly Azolla microphylla and their activities and thus in turn suppress plant growth and development. Phytotoxity of Azolla microphylla can be minimized by restrictions on application, timing, method and rate of application.
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In the present investigation, experiments were conducted to investigate the growth, morphological, anatomical and biochemical responses of to UV and drought stresses in Spilanthes acmella (toothache plant). Results were shown that both UV and drought treatments retarded plant growth. Although there was no significant difference in the internal structure of leaf and stem. Morphometric changes such as curling of leaves and shiny surface due to waxy coatings were noticed in plants grown under UV radiation however these changes were absent in water stressed plants but yellowing was observed in the entire leaves. Chlorophyll content and relative water content in leaves were significantly affected by UV and drought. Relative water content markedly increased in UV treated plants and reduced in drought. In UV treated plants chlorophyll a, chlorophyll b and total chlorophyll contents were considerably decreased than the drought treated plants. The carotenoid, flavonoids and anthocyanins concentration increased in both treatments. Changes in contents of antioxidative metabolites under the stresses were observed. Free proline and MDA accumulations also showed significant increase in drought treatment than in UV treatment. During drought condition the catalase activity decreased as compared with the control plant whereas UV treated plants showed increase in the catalase activity.
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Houttuynia cordata Thunb. is a plant enrichment in potassium in plant was reported. Salinity and low potassium availability are important environmental factors restricting plant growth and productivity throughout the world. The interactive effects of salinity and potassium on growth, water content, chlorophyll content, lipid peroxidation content, ion accumulations and K+/Na+ ratio, and organic accumulations as well as oxidative enzymes were investigated in Houttuynia cordata Thunb.. Plants of three-leaf-stage were selected for uniformity, then treated with four levels of Na+ (50, 100, 200 mmol/L) and K+ (0, 0.6, 1.2, 2.4 mmol/L) for 20 days. Plant biomass production, ratio of root and shoot, root numbers, water content and MDA content significantly declined in the combined effect of salinity and K+ deprivation, and increased with salinity. However, salinity in conjunction with K+ deprivation led to an increase on leaf chlorophyll content, which even increased with increasing salinity levels. As expected, K+ content in plant was positive correlated with supplementary K+ concentrations, while Na+ was well correlated with salinity, especially enhanced by the interactive effects of salinity and K+ deprivation. Soluble sugar and proline contents remarkable increased by the highest salinity. SOD activity also substantial increased by the highest salinity, and increased with supplementary K+ concentrations. However, elevated CAT and POD activities were not accompanied with an increase in SOD activity.
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Salinity is one the major limiting environmental factors which has negative side effects on crop production. The purpose of this study was to investigate the differences between the gradual and sudden salt stress effects on biomass accumulation associated with whole plant development in three different tissues of two wheat species (Triticum aestivum and Triticum durum) under hydroponic conditions in the long term. Considering the effects of sudden and gradual stress for biomass accumulation, while importance of salinity x genotype interaction for fresh weights was 5%, association for salinity x tissue type was found as 1% important. Interestingly, root branching and development of lateral roots were much more negatively affected by gradual stress rather than sudden salt application. Our results demonstrated that root and leaf were both critical tissues to test the salt tolerance by physiologically but sheath tissue might be used as an alternative source of variation for solving the interactions between root and leaves in wheat.
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Salinity is a serious environmental constraint to crop production in many parts of the world and the development of crops with improved salt tolerance is proposed as part of solution to this problem. This research was performed out in order to study the effects of different salinity levels on germination, growth, dry weight, proline, water soluble carbohydrate and chlorophyll content of three barley (Hordeum vulgare L.) cultivars named Jonoob (INC-54), Reyhan (INC-45) & Nosrat (INC -47).The experiment was carried out using factorial based on completely randomized design with three replications. Seven old seedlings after germination were transferred to Hoagland nutrient solution under the effect of salinity levels (0, 50, 150 and 250 mM NaCl)in during seven days. Data variance analysis showed that seed germination of three barley cultivars was significantly (P<0.01) affected by salinity levels. Minimum germination percentage was obtained in highest salinity (250mM NaCl).The sequence of reduction in germination was Jonoob>Reyhan>Nosrat. The results showed that, increasing in salinity decreased all growth parameters. Salinity stress decreased shoot and root length, root dry weight and chlorophyll contents in every three cultivars. But decreasing of chlorophyll was less in Nosrat compared to two other items. Proline content and soluble carbohydrate were increased in all of the three cultivars with enhance of NaCl concentration. By increasing of salinity stress accumulation of proline and soluble sugar content in leaves of Nosrat cultivar was more than other cultivars. As saltiness increases resistance natural responses in this plant gets better considering less decrease in chlorophyll amount and strategy of more production about praline and sugar solution compared to two other items.
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Present report deals with the effect of increasing levels (0-300 mM) of MgCl2 salt on sorghum cultivars, Phule Vasudha and Phule Revati. Although MgCl2 stress did not show considerable adverse effects on germination, however, at higher (>200 mM) concentrations, the seedlings turned brown and did not showed any further growth, with comparably higher magnitude of negative effects on Phule Revati than Phule Vasudha. Overall, increasing MgCl2 stress reduced plant growth and biomass production significantly in both the cultivars, though with lesser extent in Phule Vsudha as compared to Phule Rvati. Contrasting behavior was evidenced in both the cultivars in terms of protein content under varying levels of MgCl2 concentration at vegetative growth level, where salinity induced reduction in protein content was higher in Phule Revati than Phule Vasudha. The genotype Phule Vasudha showed higher proline content under non-saline condition. MgCl2 stress-induced proline accumulation was observed in both the sorghum cultivars, however, interestingly, Phule Revati (439% of control plants) showed comparably higher proline content than Phule Vasudha (324% of control plants) at the highest (300 mM) level of stress. Even though, malondialdehyde (MDA: lipid peroxidation indicator) content was on higher side under non-saline conditions in cultivar Phule Vasudha as compared to cultivar Phule Revati, however the rate of increase in MDA with increasing salt stress was much higher in the latter cultivar, indicating the comparably higher level of lipid peroxidation under the influence of MgCl2 stress. The salt tolerance nature of Phule Vasudha was positively correlated with its better performance in terms of physiological and biochemical parameters.
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The combined effect of cadmium stress (0,5 mM Cd(NO3)2) and salt stress (100 mM NaCl) on growth, lipid peroxidation and activities of some antioxidant enzymes were studied in soybean (Glycine max L. Merr.) leaves. Shoot lenghts were not changed under all groups. But fresh and dry weight were decreased under salt treatment alone and Cd treatment alone. The decrease was more in the group of combined of Cd and salt treatment. Although APX activity increased under salt treatment alone and combined of Cd and salt treatment, GR activity increased under Cd treatment alone and combined of Cd and salt treatment. Nevertheless DHAR activity increased only in combined of Cd and salt stress. MDA content increased under all groups but it was more in the combined of Cd and salt stress which indicates that salinity is more harmful with cadmium stress in soybean plants. Thus, it was concluded that some of antioxidant enzymes (APX, GR, DHAR) increased their activity under combined of Cd and salt treatment but they were not efficient to protect oxidative damage from soybean plants by alleviating the lipid peroxidation.
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The objective of the present study investigated on the effects Satureia hortensis L seeds exposure to magnetic fields on seed germination, early growth and enzyme activity, under laboratory conditions Satureia hortensis seeds (dry and wet) were studied after treating with different intensities of magnetic field (0, 25, 50 and 75 mT) and exposure time (0, 30 and 60 min). There were significant effects among treatments for germination percentage, root length, shoot length, seedling dry mass and seedling vigor index in Satureia hortensis seeds under different magnetic intensity. In the germinating seeds enzyme activities of α-amylase, dehydrogenase and protease were significantly higher in treated seeds in contrast to control.
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Soil salinity is one of the most severe factors limiting growth and physiological response in cowpea plants. In this study, the low concentrations of NaCl (25mM) increased plant growth, photosynthetic pigments content, total soluble protein content, nucleic acids contents (DNA and RNA), lipid peroxidation, non enzymatic antioxidants (anthocyanin, ascorbic acids and α-tocopherol), number of legumes per plant, number of seeds per legume, number of seeds per plants, legume length, fresh and dry weight of legumes and weight of 1000 seeds and total soluble proteins and carbohydrate contents in harvested seeds as compared to control. On the other hand, the high concentrations of NaCl (50, 100 and 200 mM) caused reduction in plant growth, photosynthetic pigments content, total soluble protein content, nucleic acids contents (DNA and RNA), all yield attributes and harvested seeds components but increased lipid peroxidation and non enzymatic antioxidants (anthocyanin, ascorbic acids and α-tocopherol). Electrophoretic studies of proteins showed three types of modifications are observed in the protein patterns of cowpea seeds, some protein bands were disappeared, other proteins were selectively increased and synthesis of new set of protein was induced. Some of these responses were observed under gamma rays and salinity treatments, while others were induced by either gamma rays or salinity. Seeds irradiation with gamma rays alleviates the adverse effect of salt stress compared to non irradiated seeds.
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Pranayama aims by carrying the involuntary functions of the respiratory mechanism within human control. The term pranayama has comprised by two words: Prana + Ayama. Prana is the vital force and energy which permeates the whole universe. Prana is novel subtle than air and can be defined as the energy essence that is within everything in the universe. In present time emphasis is on the beneficial effects of Pranayam in various diseases i.e. diabetes mellitus, hypertension, obesity and depression by application of specific exercise like walking in a planned way. This was also explained and proved by American college of sport medicine. In Ayurveda various breathing exercise and yogic practices have been mentioned. The respiratory System, central nervous system and cardiovascular system are the important systems which are mostly affected by Pranayam and other physical activities. Breathing exercise is highly effective in endorsement of respiratory system and management of diseases related to respiratory system.
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Many small mammals inhabiting cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (NST) and thermoregulatory maximum metabolic rate (MMR). However, it is not known how this plasticity remains in a mammal that rarely experiences extreme cold fluctuations. In order to answer this question, we determined body mass (Mb), basal metabolic rate (BMR), NST, and MMR on a tree shrews (Tupaia belangeri), acclimated to cold (5 ºC) conditions. NST was measured as the maximum response of metabolic rate (NSTmax) after injection of norepinephrine (NE) in thermoneutrality minus BMR. Maximum metabolic rate was assessed in animals exposed to enhanced heat-loss atmosphere (He-O2) connected with an open-flow respirometer. Body mass and metabolic variables increased significantly after cold acclimation with respect to control group but to a high extent (BMR, 87.97%; NST, 69.77%; and MMR, 32.35%). However, aerobic scope (MMR/BMR), and calculated shivering thermogenesis (ST) did not significantly change with control group. Our data suggest: 1). The body mass and the capacity of heat production in the cold acclimated group were higher; 2). The increase of BMR and MMR during cold acclimation was the main pattern of heat production in the tree shrews.
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Salinity is considered as the most important abiotic stress limiting crop production and plants are known to be able continuing survive under this stress by involving many mechanisms. In this content, the present study was carried out to evaluate the impact of NaCl on some physiological and biochemical parameters in five Tunisian chili pepper (Capsicum frutescens L.) cultivars: Tebourba (Tb), Somaa (Sm), Korba (Kb), Awald Haffouzz (AW) and Souk jedid (Sj). Thus, an experiment of five months was carried out under greenhouse at Higher Institute of Agronomy, Chott Meriem, Tunisia and stress is induced by NaCl at 7 concentrations (0, 2, 4, 6, 8, 10 and 12g/l). Results showed that increasing salinity stress, for all cultivars, had a negative impact on roots (length, fresh and dry weights) and leaves (number and area). Also, chlorophyll (a and b) amount in addition to quantium yield (Fv/Fm) decreased significantly. However, biosynthesis of proline in leaves is activated. Awlad Haffouzz and Korba cultivars succefully tolerated highest salinity level by accumulating more proline in leaves and maintaining usually higher values in all parameters in opposition to Souk jedid cultivar. Taken together, our data partly explain the mechanism used to ovoid salt stress by pepper plants when excessive in the culture medium.
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Impacts of various concentrations of polyetylenglycol 6000 (PEG 6000) (0, -9, -11, -13 and -15 bar) and hydro priming on Mountain Rye (secale montanum) germination characteristic and enzyme activity were evaluated under drought stress in the seed laboratory of Natural Resources Faculty, University of Tehran, Karaj, Iran. Analyze of variance for hydro priming showed that temperature × time of priming interaction was significantly for germination percentage (GP), normal seedling percentage (NSP), coefficient of velocity of germination (CVG), seedling vigor index (SVI), coefficient of allometry (AC) and seedling length (SL) under drought stress and for osmo priming showed that Concentration of PEG × Temperature × Time of priming interaction was significantly for all traits under drought stress. Results of interaction effects for hydro priming showed that the highest GP (53%) and NSP (23.5%) were attained from hydro priming for 16h at 15◦C and the highest CVG (0.21) and AC (0.49) were attained from hydro priming for 8h at 10◦C, also hydro priming for 8h at 15◦C increased SL (3.15) as compared to the unprimed. Osmo priming with concentration of -15 bar PEG for 24h at 15◦C increased GP (80.5 %), GI (17.9), NSP (45 %), SVI (257.85) and SL (5.73 cm) and decreased MTG as compared to the unprimed and other treatments of osmo priming. The highest CVG was attained from concentration of -9 bar PEG for 24h at 10◦C. the highest AC was attained from concentration of -9 bar PEG for 12h at 15◦C. Also osmo and hydro priming increased catalase (CAT) and ascorbate peroxidase (APX) as compared to the unprimed.
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Seedlings of bean plants (Phaseolus vulgaris L.Sel 9) were grown for 2 weeks with half strength Hoagland solution containing 0 ppm (deficient), 5 ppm (sufficient) and 50 ppm (excess) ZnSO4.7H2O. Changes in photosynthetic pigments, soluble proteins, soluble starch, photosystem (PSII) activities and thylakoid membrane proteins were investigated. The degree of photoinhibition was determined by the ratio of variable to maximum chlorophyll (Chl) fluorescence (Fv/Fm). Photosynthetic pigments, soluble proteins and soluble starch decreased significantly in Zn-deficient and Zn-excess leaves. Though the maximum quantum yield of primary photochemistry (Fv/Fm), maximum variable fluorescence (Fv) were significantly decreased to a greater extent in Zn-excess leaves the restoration was excellent. The exogenous electron donors, diphenylcarbazide (DPC) and NH2OH restored the loss of PSII activity in Zn-deficient and Zn-excess leaves. A slight degradation 33, 28-25, 23 and 17 kDa polypeptides were observed in the Zn-deficient and Zn-excess leaves. Upon recovery from HI stress, the Zn-excess leaves restored the 47, 33, and 28-25 kDa polypeptides.
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The data on the influence of different concentration of sodium nitroprusside (SNP), potassium nitrate (KNO3), sodium nitrite (NaNO2) and L-arginine on 3 days-old etiolated pea seedlings growth and nitric oxide (NO) content in roots of these seedlings are obtained. It is found that 24 h exposition of seedlings to SNP showed negative influence on growth at a 4 mM dose; SNP at 0.05 mM doze stimulates their growth and 0.1 mM doze did not influence on seedlings growth. Using KNO3 negative influence on growth at the same exposition was showed only at superhigh concentration - 20 mM. Using NaNO2 negative influence on growth was shown at a doze of 2 mM but concentration of 0.1 and 0.5 mM did not influence on it. The exposition of seedlings to L-arginine caused growth inhibition already at concentration of 0.5 mM and reached maximum at 4 mM doze. Determination of NO level in roots using fluorescent probe DAF-2DA in variants with the greatest growth inhibition has showed, that the maximal inhibition of growth in roots and highest level of NO in roots in variants with SNP (4 mM) and NaNO2 (2 mM) was observed. In variants with KNO3 (20 mM) and L-arginine (4 mM) maximal growth inhibition did not coincide with NO accumulation and was observed after 30 min after the beginning of plants exposition and further it was reduced in 24 h. Results are discussed in connection with possible influence NO and participation of the investigated connections in generation nitric oxide in roots of pea seedlings.
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In present study the determination of cellular metabolic markers under exposure of Lake Baikal endemic amphipod Eulimnogammarus verrucosus (Amphipoda, Crustacea) in a wide range of ambient temperatures was carried out. The metabolic data was compared with species termopreferendum data obtained in our previous studies. It was found that exposure of amphipods under increased temperatures resulted in increase of HSP70 content and lactate, activating of antioxidant enzymes (catalase and peroxidase), as well as reduction of lactate dehydrogenase and glutathione S-transferase activities. Exposure of E. verrucosus at low temperatures resulted in decrease of HSP70 content, increase of lactate level, peroxidase and lactate dehydrogenase activation, and reduction of glutathione S-transferase activity. It was noted that the most expressed changes of metabolism markers in the species observed when temperature threshold was exceeded 11°C or then temperature dropped below 4°C. The temperature range 4-11°C represented the area of stability of cellular metabolic markers in E. verrucosus and correlated with a preferred temperature limits, previously obtained in behavioral experiments. Thus, for a first time with Lake Baikal amphipods we showed that the zone of stability of cellular metabolism in E. verrucosus closely related to their behavioral thermal preference zones and is likely to reflect thermal optima limits of the species.
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Gas exchange parameters and chlorophyll fluorescence of four pot grown Galician grapevines (Vitis vinifera L. cv. Albariño, Brancellao, Godello and Treixadura) were examined under different levels of water stress in greenhouse. After extreme stress, gas exchange recovery responses were evaluated. Average ΨPD for control and stressed plants were -0.4MPa and -1.45MPa respectively. All varieties showed gradual declining of all gas exchange parameters (gs, E and A) with increasing of stress periods. Under stressed conditions, Albariño and Godello showed higher CO2 assimilation rate. At the end of stress period leaf defoliation was found in Albariño and Brancellao. Gas exchange recovery was higher for both Godello and Treixadura. A better response of auxiliary bud recovery was present in Albariño than in Brancellao. Close correlations between water stress and gas exchange parameters were found and it varies on genotype. Albariño, Godello and Treixadura followed same diurnal patterns of gas exchange rate for control and stressed plant respectively. Diurnal pattern of CO2 assimilation rate of all tested varieties followed gs and E. Only Brancellao showed treatment effect on mid-day Fv/Fm. Among four varieties photoinhibition was only found in Brancellao. At stressed condition physiological responses of grapevines were genotype depended.
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The aim of present study was the evaluation of the antioxidant enzyme's activity and activity of anaerobic glycolysis enzymes under gradual temperature increase in Baikal amphipods species Eulimnogammarus marituji (Baz., 1945), E. maackii (Gerstf, 1858) and Gmelinoides fasciatus (Stebb., 1899). In all species under gradual temperature increase exposition elevation of peroxidase' activity was observed. Activities of catalase', glutathione S - transferase' and lactate dehydrogenase' activity in E. marituji and E. maacki were differed from G. fasciatus. It was proposed that changes in the antioxidant enzyme's activity and activity of anaerobic glycolysis enzymes in Baikal amphipods may contribute to increasing of glycolytic processes functional efficiency and keeping of energetic homeostasis in endemic organisms.
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