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Salinity Conditions (salinity + condition)

Distribution by Scientific Domains

Earth and Environmental Science	46%
Life Sciences	40%

Selected Abstracts

Purification and Kinetic Characterization of Peroxidase from Tomato Cultivated under Different Salinity Conditions

JOURNAL OF FOOD SCIENCE, Issue 1 2000
J.N. Rodríguez-López
ABSTRACT: By including hydrophobic chromatography in the purification scheme, 2 homogeneous tomato fruit peroxidase isoenzymes were obtained. The expression of these 2 peroxidases, one acid and the other basic, was determined in tomato fruits grown under different salinity conditions. Increased salinity modified the isoenzyme profile of tomato peroxidase. In tomatoes grown under highly saline conditions, there was an increase in the expression of the acid form with respect to the basic, the acid/basic ratio rising from 4.5 in tomatoes grown under normal saline conditions to 70 in those grown in highly saline conditions. Kinetic studies using 2,2,-azinobis(3-ethylbenzo-thiazolinesulfonic acid) as reducing substrate showed that increased salinity in the growth medium did not modify the kinetic parameter of tomato peroxidase over both hydrogen peroxide or reducing substrate. [source]

Salinity tolerance in young Allis shad larvae (Alosa alosa L.)

ECOLOGY OF FRESHWATER FISH, Issue 1 2008
A. Bardonnet
Abstract,,, Estuarine migration in Allis shad (Alosa alosa) usually does not take place before mid-summer, but exposure to salinity in brackish water may occur earlier as many spawning areas are of necessity located in upper estuarine zones due to the placement of dams. Therefore, Allis shad conservation programmes need to consider the risk of mortality due to the ability of young Allis shad to tolerate salinity. To evaluate larval mortality due to the inability of larvae to withstand salinity during early ontogeny, we exposed larvae of different ages (from few days old to 27 days old) to salinities ranging from 0 to 30 g·l,1. Results indicate that direct seawater exposure induces high mortality in young larvae whatever the ontogenetic stage. However, young larvae can easily deal with upper estuary salinity conditions. [source]

Relative contributions from exposed inshore and estuarine nursery grounds to the recruitment of stone flounder, Platichthys bicoloratus, estimated using otolith Sr:Ca ratios

FISHERIES OCEANOGRAPHY, Issue 4 2000
Yoh Yamashita
In Sendai Bay, stone flounder larvae settle and spend their juvenile period in either shallow exposed inshore nursery grounds or estuarine nursery grounds. The purpose of this study is to examine the relative contributions of these two kinds of nursery grounds to the flounder population using otolith strontium:calcium ratios. Stone flounder juveniles were collected from both nursery grounds, and one- and two-year-old flounder were caught deeper in Sendai Bay. Sr and Ca content in the otoliths were measured by electron probe micro analysis. The Sr:Ca ratios in the otolith section corresponding to the early postsettlement period ranged from 3.06 to 3.85 for the exposed inshore areas with stable low temperature and high salinity conditions, and from 3.81 to 5.32 in brackish estuaries with high temperature and low salinity conditions but with large diel and tidal cyclical fluctuations. Values from an estuarine site with stable salinity ranged from 3.58 to 4.15 overlapping with both the above ranges. Rearing experiments supported our inference that the high otolith Sr:Ca ratios of juveniles inhabiting estuarine nursery grounds are attributable to higher temperature and physiological stress caused by the large diel temperature and salinity fluctuations within the estuaries. Estimation of the Sr:Ca ratio of recruited fish using the otolith section formed while in the nursery area showed that at least 20 out of 42 individuals examined originated from estuarine nursery grounds. The present study indicates that estuaries play an important role as nursery grounds for stone flounder, producing about half of the stock in spite of the small and restricted area compared with the wide expanse of the exposed inshore area. [source]

Purification and Kinetic Characterization of Peroxidase from Tomato Cultivated under Different Salinity Conditions

Genetic Diversity and Association Analysis for Salinity Tolerance, Heading Date and Plant Height of Barley Germplasm Using Simple Sequence Repeat Markers

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2008
Lilia Eleuch
Abstract The objective of this study was to investigate the genetic diversity of barley accessions. Additionally, association trait analysis was conducted for grain yield under salinity, heading date and plant height. For this purpose, 48 barley genotypes were analyzed with 22 microsatellite simple sequence repeat (SSR) markers. Four of the 22 markers (Bmac316, scssr03907, HVM67 and Bmag770) were able to differentiate all barley genotypes. Cluster and principal coordinate analysis allowed a clear grouping between countries from the same region. The genotypes used in this study have been evaluated for agronomic performance in different environments. Conducting association analysis for grain yield under salinity conditions using TASSEL software revealed a close association of the marker Bmag749 (2H, bin 13) in two different environments with common significant alleles (175, 177), whereas the HVHOTR1 marker (2H, bin 3) was only significant in Sakhar_Egypt with alleles size being 158 and 161. Heading date also showed an association with scssr03907 through the common significant specific allele 111 and EBmac0415 markers in three different agro climatic locations, whereas HVCMA, scssr00103 and HVM67 were linked to heading date in the Egyptian environment only. The plant height association analysis revealed significant markers Bmag770 via the significant allele 152 and scssr09398. [source]

Melting out of sea ice causes greater photosynthetic stress in algae than freezing in,

JOURNAL OF PHYCOLOGY, Issue 5 2007
Peter J. Ralph
Sea ice is the dominant feature of polar oceans and contains significant quantities of microalgae. When sea ice forms and melts, the microalgal cells within the ice matrix are exposed to altered salinity and irradiance conditions, and subsequently, their photosynthetic apparatuses become stressed. To simulate the effect of ice formation and melting, samples of sea-ice algae from Cape Hallett (Antarctica) were exposed to altered salinity conditions and incubated under different levels of irradiance. The physiological condition of their photosynthetic apparatuses was monitored using fast and slow fluorescence-induction kinetics. Sea-ice algae exhibited the least photosynthetic stress when maintained in 35, and 51, salinity, whereas 16, 21, and 65, treatments resulted in significant photosynthetic stress. The greatest photosynthetic impact appeared on PSII, resulting in substantial closure of PSII reaction centers when exposed to extreme salinity treatments. Salinity stress to sea-ice algae was light dependent, such that incubated samples only suffered photosynthetic damage when irradiance was applied. Analysis of fast-induction curves showed reductions in J, I, and P transients (or steps) associated with combined salinity and irradiance stress. This stress manifests itself in the limited capacity for the reduction of the primary electron receptor, QA, and the plastoquinone pool, which ultimately inhibited effective quantum yield of PSII and electron transport rate. These results suggest that sea-ice algae undergo greater photosynthetic stress during the process of melting into the hyposaline meltwater lens at the ice edge during summer than do microalgae cells during their incorporation into the ice matrix during the process of freezing. [source]

Drought and salinity: A comparison of their effects on mineral nutrition of plants

JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2005
Yuncai Hu
Abstract The increasing frequency of dry periods in many regions of the world and the problems associated with salinity in irrigated areas frequently result in the consecutive occurrence of drought and salinity on cultivated land. Currently, 50% of all irrigation schemes are affected by salinity. Nutrient disturbances under both drought and salinity reduce plant growth by affecting the availability, transport, and partitioning of nutrients. However, drought and salinity can differentially affect the mineral nutrition of plants. Salinity may cause nutrient deficiencies or imbalances, due to the competition of Na+ and Cl, with nutrients such as K+, Ca2+, and NO. Drought, on the other hand, can affect nutrient uptake and impair acropetal translocation of some nutrients. Despite contradictory reports on the effects of nutrient supply on plant growth under saline or drought conditions, it is generally accepted that an increased nutrient supply will not improve plant growth when the nutrient is already present in sufficient amounts in the soil and when the drought or salt stress is severe. A better understanding of the role of mineral nutrients in plant resistance to drought and salinity will contribute to an improved fertilizer management in arid and semi-arid areas and in regions suffering from temporary drought. This paper reviews the current state of knowledge on plant nutrition under drought and salinity conditions. Specific topics include: (1) the effects of drought and salt stress on nutrient availability, uptake, transport, and accumulation in plants, (2) the interactions between nutrient supply and drought- or salt-stress response, and (3) means to increase nutrient availability under drought and salinity by breeding and molecular approaches. Trockenstress und Salzstress , Vergleich der Auswirkungen auf die mineralische Ernährung von Pflanzen Eine Zunahme von Trockenperioden in vielen Ländern der Welt und assoziierte Probleme der Versalzung in bewässerten Gebieten führen häufig zu gleichzeitigem Auftreten von Trockenheit und Salinität. Gegenwärtig sind weltweit ungefähr 50 % aller Bewässerungsflächen durch Salinität beeinträchtigt. Nährstoffstörungen bei Trocken- und Salzstress beeinträchtigen die Verfügbarkeit, den Transport und die Verteilung von Nährelementen in der Pflanze und reduzieren somit das Pflanzenwachstum. Trocken- und Salzstress können sich jedoch unterschiedlich auf die Nährstoffversorgung der Pflanzen auswirken. Salinität kann aufgrund der Konkurrenz zwischen Na+ bzw. Cl, und Nährelementen wie K+, Ca2+ und NO Nährstoffmängel oder -ungleichgewichte in den Pflanzen verursachen. Trockenstress kann sowohl die Nährstoffaufnahme als auch den akropetalen Transport einiger Elemente beeinträchtigen. Trotz kontroverser Schlussfolgerungen in der Literatur hinsichtlich der Wechselbeziehungen von Nährstoffangebot und Trocken- bzw. Salzstress auf das Pflanzenwachstum ist allgemein akzeptiert, dass Nährstoffzufuhr das Pflanzenwachstum nicht verbessert, wenn ausreichend Nährstoffe im Boden verfügbar sind oder bei stark ausgeprägter Trockenheit oder Salinität. Ein besseres Verständnis der Rolle von Mineralstoffen in der Toleranz von Pflanzen gegenüber Trocken- oder Salzstress dürfte gerade in ariden und semi-ariden Gebieten sowie in Regionen, die unter periodischer Trockenheit leiden, zu verbesserten Düngestrategien beitragen. In der vorliegenden Arbeit wird der gegenwärtige Kenntnisstand der mineralischen Ernährung bei Trockenheit und Salinität diskutiert. Schwerpunkte der Betrachtungen sind (1) die Auswirkungen von Trockenheit und Salzstress auf die Verfügbarkeit, die Aufnahme, den Transport und die Anreicherung von Nährelementen in der Pflanze, (2) Wechselbeziehungen zwischen dem Nährstoffangebot und Trockenheit oder Salinität sowie (3) Maßnahmen zur Verbesserung der Nährstoffverfügbarkeit bei Trockenheit und Salzstress mittels züchterischer und molekularbiologischer Ansätze. [source]

Effects of Light Intensity and Salinity on Growth, Survival, and Whole-Body Osmolality of Larval Southern Flounder Paralichthys lethostigma

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2003
James P. Henne
The southern flounder Paralichthys lethosligma is a high-valued flatfish found in estuarine and shelf waters of the south Atlantic and Gulf coasts of the United States. Wide temperature and salinity tolerances exhibited by juveniles and adults make it a versatile new candidate for commercial culture, and studies are underway in the southeastern U.S. to develop hatchery methods for this species. The objectives of this study were to establish illumination and salinity conditions that optimize growth and survival of larval southern flounder reared through the yolk-sac and first feeding stages to 15-d post-hatching (15 dph). Early embryos were stocked into black 15-L tanks under light intensities of 5, 50, 100, and 1,000 Ix and at salinities of 24 and 34 ppt in a 4 ± 2 factorial design. Significant (P 0.05) effects of both light intensity and salinity on growth and survival were obtained, with no interaction between these effects. On 11 dph and 15 dph, growth was generally maximized at the intermediate light intensities (50 and 100 Ix) and minimized at the extremes (5 and 1,000 Ix). By 15 dph, growth was higher at 34 ppt than at 24 ppt. Survival to 15 dph showed trends similar to those of growth. Survival was higher at 100 Ix (avg. = 46%, range = 41,54%) than at 5 Ix (avg. = 11%, range = 6,17%) and higher at 34 ppt (avg. = 43%, range = 3145%) than at 24 ppt (avg. = 17%, range = 8,38%). Whole-body osmolality (mOsmol/kg) was significantly lower in larvae reared at 24 ppt (avg. = 304, range = 285,325) through 11 dph than in larvae reared at 34 ppt (avg. = 343, range = 296,405). Larvae reared under the extreme light intensity treatments (5 and 1,000 Ix) at 34 ppt appeared to exhibit osmoregulatory stress, particularly on 11 dph, when a marked increase in whole-body osmolality was observed. The mid-intensity treatments (50 and 100 Ix) at 34 ppt optimized growth and survival of larval southern flounder in this study; and elicited the most stable osmotic response. These conditions appear to be consistent with those that southern flounder larvae encounter in nature during this early developmental period. [source]

Gene expression profiling of Dunaliella sp. acclimated to different salinities

PHYCOLOGICAL RESEARCH, Issue 1 2010
Minjung Kim
SUMMARY To investigate which genes may be important for growth under extreme conditions such as very low or high salinities, a survey of the Dunaliella sp. transcriptome was performed with a cDNA microarray which had been generated previously representing 778 expressed sequence tags. The comparative microarray analysis indicated that 142 genes differed in expression levels by more than twofold in cells grown at extreme salinities (0.08 M and 4.5 M NaCl) when compared with cells grown at intermediate salinity (1.5 M NaCl). Of these genes, 28 had increased expression and 57 were suppressed in cells grown at low salinity. In cells grown at high salinity, 43 genes showed increased expression and 69 genes showed suppressed expression. However, we did observe a large overlap in the expression of extreme salinity-responsive genes based on Venn diagram analysis, which found 55 genes that responded to both of the two extreme salinity conditions. Further, we found that several genes had similar expression levels under low and high salinities, including some general stress response genes that were upregulated in both extreme salinity conditions. For confirmation of the validity of the cDNA microarray analysis, expression of several genes was independently confirmed by the use of gene-specific primers and real-time polymerase chain reaction. The present study is the first large-scale comparative survey of the transcriptome from the microalga Dunaliella sp. acclimated to extreme salinities, thus providing a platform for further functional investigation of differentially expressed genes in Dunaliella. [source]

Heterologous expression of Arabidopsis H+ -pyrophosphatase enhances salt tolerance in transgenic creeping bentgrass (Agrostis stolonifera L.)

PLANT CELL & ENVIRONMENT, Issue 2 2010
ZHIGANG LI
ABSTRACT The Arabidopsis vacuolar H+ -pyrophosphatase (AVP1), when over-expressed in transgenic (TG) plants, regulates root and shoot development via facilitation of auxin flux, and enhances plant resistance to salt and drought stresses. Here, we report that TG perennial creeping bentgrass plants over-expressing AVP1 exhibited improved resistance to salinity than wild-type (WT) controls. Compared to WT plants, TGs grew well in the presence of 100 mm NaCl, and exhibited higher tolerance and faster recovery from damages from exposure to 200 and 300 mm NaCl. The improved performance of the TG plants was associated with higher relative water content (RWC), higher Na+ uptake and lower solute leakage in leaf tissues, and with higher concentrations of Na+, K+, Cl - and total phosphorus in root tissues. Under salt stress, proline content was increased in both WT and TG plants, but more significantly in TGs. Moreover, TG plants exhibited greater biomass production than WT controls under both normal and elevated salinity conditions. When subjected to salt stress, fresh (FW) and dry weights (DW) of both leaves and roots decreased more significantly in WT than in TG plants. Our results demonstrated the great potential of genetic manipulation of vacuolar H+ -pyrophosphatase expression in TG perennial species for improvement of plant abiotic stress resistance. [source]

Physiological responses of pink abalone Haliotis corrugata (Gray, 1828) exposed to different combinations of temperature and salinity

AQUACULTURE RESEARCH, Issue 7 2010
Zarina Medina Romo
Abstract Physiological responses of pink abalone Haliotis corrugata were determined under different temperature and salinity conditions. Oxygen consumption rate was not affected by temperature and salinity. Ammonium excretion of pink abalone was inversely related to salinity. The O:N ratio indicated that abalone maintained in lower salinities had an interval of 4.9,7.7, which is indicative of a protein-dominated metabolism, whereas the O:N in 35, was 28.8,35.5 for both temperatures, suggesting that carbohydrates were used as energy substrate. Haemolymph osmolality of abalone exposed to 20 and 24 °C was slightly hyperiso-osmoconformic in salinity ranges of 20,35,. The results of this study suggested that for optimized culture, pink abalone should be cultivated at 24 °C at a salinity of 35,. [source]

Comparative activity and stability under salinity conditions of different antimicrobial peptides isolated from aquatic animals

AQUACULTURE RESEARCH, Issue 16 2009
Sara Emelie Löfgren
Abstract This study reports the in vitro activity of six antimicrobial peptides (AMPs) produced by aquatic animals (most marine invertebrates): tachyplesin (Tach), magainin (Mag), clavanin (Clav), penaeidin (Pen), mytilin (Myt) and antilipopolysaccharide factor (ALF) against marine vibrios, filamentous fungi and yeast. Their stability under salinity conditions and seawater was also examined. The results showed that Mag, Myt and especially Tach and ALF (minimum inhibitory concentration<1.5 ,M) had a potent activity against all tested vibrio species, whereas Clav and Pen were ineffective (up to 50 ,M). With respect to the antifungal activity, each AMP had a different potency according to the fungal species. In general terms, Tach was the most potent peptide, followed by Mag. Interestingly, Tach, Myt and ALF had a significant effect on the filamentous fungus Fusarium solani that could be pathogenic to marine organisms. All AMPs had a tendency to decrease or lose their activity at high salinity (>225 mM NaCl). Tach and Myt were the most stable peptides, maintaining significant activity under seawater salinity (450 mM). Curiously, all peptides lost their effect under seawater conditions. The results suggest that Tach, ALF and Myt are the most promising candidates for potential therapeutic use in farmed-marine species, because all have a significant and broad antimicrobial activity maintained at high salinity. [source]

Effects of temperature and salinity on the survival and development of mud crab, Scylla serrata (Forsskål), larvae

AQUACULTURE RESEARCH, Issue 14 2007
Rahmi Nurdiani
Abstract The combined effects of temperature and salinity on larval survival and development of the mud crab, Scylla serrata, were investigated in the laboratory. Newly hatched larvae were reared under 20 °C temperature and salinity combinations (i.e. combinations of four temperatures 25, 28, 31, 34 °C with five salinities 15, 20, 25, 30, 35 g L,1). The results showed that temperature and salinity as well as the interaction of the two parameters significantly affected the survival of zoeal larvae. Salinity at 15 g L,1 resulted in no larval survival to the first crab stage, suggesting that the lower salinity tolerance limit for mud crab larvae lies somewhere between salinity 15 and 20 g L,1. However, within the salinity range of 20,35 g L,1, no significant effects on survival of zoeal larvae were detected (P>0.05). The combined effects of temperature and salinity on larval survival were also evident as at low salinities, both high and low temperature led to mass mortality of newly hatched larvae (e.g. 34 °C/15 g L,1, 34 °C/20 g L,1 and 25 °C/15 g L,1 combinations). In contrast, the low temperature and high salinity combination of 25 °C/35 g L,1 resulted in one of the highest survival to the megalopal stage. It was also shown that at optimal 28 °C, larvae could withstand broader salinity conditions. Temperature, salinity and their interaction also significantly affected larval development. At 34 °C, the mean larval development time to megalopa under different salinity conditions ranged from 13.5 to 18.5 days. It increased to between 20.6 and 22.6 days at 25 °C. The effects of salinity on larval development were demonstrated by the fact that for all the temperatures tested, the fastest mean development to megalopa was always recorded at the salinity of 25 g L,1. However, a different trend of salinity effects was shown for megalopae as their duration consistently increased with an increase in salinity from 20 to 35 g L,1. In summary, S. serrata larvae tolerate a broad range of salinity and temperature conditions. Rearing temperature 25,30 °C and salinity 20,35 g L,1 generally result in reasonable survival. However, from an aquaculture point of view, a higher temperature range of 28,30 °C and a salinity range of 20,30 g L,1 are recommended as it shortens the culture cycle. [source]

Interspecific competition and rarity in mudsnails: feeding interactions between and within Hydrobia acuta neglecta and sympatric Hydrobia species

AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 5 2005
R.S.K. Barnes
Abstract 1.Using production of faecal pellets as a proxy for feeding rate, possible reciprocal effects of the widespread and abundant mudsnails Hydrobia ulvae and Hydrobia ventrosa on the rare Hydrobia acuta neglecta were investigated under the sea-water salinity conditions in which all three species occur naturally in East Anglia, UK. 2.Over a density range equivalent to 1000,34 000 m,2, H. acuta and H. ventrosa (though not H. ulvae) at some point displayed an intraspecific reduction in egestion with increase in density. For H. acuta, every 5000 extra snails above a threshold of 16 000 m,2 reduced egestion by up to 8%; and for H. ventrosa, every 5000 extra snails above a threshold of 8000 m,2 reduced egestion by an average 7%. 3.Keeping the density of one test species constant at 4000 m,2 whilst varying that of a sympatric one from 0 up to 30 000 m,2 indicates that H. ulvae has a marked effect on H. acuta at all densities, decreasing its egestion by 10% for every 5000 m,2H. ulvae also present, but that H. acuta has no such reciprocal effect on H. ulvae. H. ventrosa had no effect on egestion in H. acuta, although H. acuta did have some minor effect on H. ventrosa, on average decreasing its egestion by 3% for every 5000 m,2H. acuta present. 4.The intensity of intraspecific competition within H. acuta, therefore, exceeds that exerted on H. acuta by H. ventrosa, and likewise intraspecific effects within H. ventrosa generally outweigh any interspecific effect from H. acuta. The effect of H. ulvae on H. acuta, however, exceeds that intraspecifically within H. acuta. 5.These results are discussed in relation to the rarity of H. acuta neglecta. Copyright © 2005 John Wiley & Sons, Ltd. [source]