Accumulation Of Organic Solutes Research Articles

AnWRKY29 and AnHSP90 synergistically modulate trehalose levels in a desert shrub leaves during osmotic stress.

Trehalose, a biological macromolecule with osmotic adjustment properties, plays a crucial role during osmotic stress. As a psammophyte, Ammopiptanthus nanus relies on the accumulation of organic solutes to respond to osmotic stress. We utilized virus-induced gene silencing technology for the first time in the desert shrub A. nanus to confirm the central regulatory role of AnWRKY29 in osmotic stress, as it controls the transcription of AnTPS11 (trehalose-6-phosphate synthase 11). Further investigation has shown that AnHSP90 may interact with AnWRKY29. The AnHSP90 gene is sensitive to osmotic stress, underscoring its pivotal role in orchestrating the response to such adverse conditions. By directly targeting the W-box element within the AnTPS11 promoter, AnWRKY29 effectively enhances the transcriptional activity of AnTPS11, which is facilitated by AnHSP90. This discovery highlights the critical role of AnWRKY29 and AnHSP90 in enabling organisms to adapt to and cope effectively with osmotic stress, which can be a crucial factor in A. nanus survival and overall ecological resilience. Collectively, uncovering the molecular mechanisms underlying the osmotic responses of A. nanus is paramount for comprehending and augmenting the osmotic tolerance mechanisms of psammophyte shrub plants.

NPK fertilization modulates enzyme activity and mitigates the impacts of salinity on West Indian cherry.

Salt stress causes several physiological and biochemical disorders and impairs plant growth. However, adequate fertilization can improve the nutritional status and may reduce significantly the harmful effects caused by salt stress. From this perspective, this study aimed to evaluate the impact of different combinations of nitrogen, phosphorus and potassium fertilization on the antioxidant activity and accumulation of organic and inorganic solutes in West Indian cherry leaves, in the second year of production. The experimental design was in randomized blocks, with treatments distributed in a 10 × 2 factorial arrangement corresponding to ten fertilization combinations (FC) of NPK (FC1: 80-100-100%, FC2:100-100-100%, FC3:120-100-100%, FC4:140-100-100%, FC5:100-80-100%, FC6:100-120-100%, FC7:100-140-100%, FC8:100-100-80%, FC9:100-100-120%, and FC10:100-100-140% of the recommendation) and two levels of electrical conductivity of irrigation water (ECw) (0.6 and 4.0 dS m-1), with three replications. The multivariate analysis showed that irrigation with water of different electrical conductivities (0.6 and 4.0 dS m-1) resulted in different responses concerning the enzyme activity, production of organic compounds, and accumulation of inorganic solutes in the leaves. Under irrigation with low salinity water, there was greater accumulation of K+, soluble carbohydrates, and proline, and lower activity of antioxidative enzymes, especially SOD and APX. Under high salinity water, greater enzyme activity and higher concentrations of Na+ and Cl- were observed. The results indicate that the response of West Indian cherry to salinity was more towards redox homeostasis than osmotic homeostasis through the accumulation of compatible solutes. Fertilization combination FC5 (100-80-100% corresponding to 200, 24 and 80 g plant-1 of NPK) modulates the enzyme activity of SOD and APX attenuating the impacts of salinity, being an efficient combination to preserve redox homeostasis in West Indian cherry plants grown under salt stress.

Growth, Dry Mass and Organics Solutes Accumulation in Cnidoscollus phyllacanthus (M. Arg) Pax & Hoffm.) Seedlings Under Salinity

Theoretical framework: The areas affected by salinity have increased in recent years, becoming a limiting factor for plants, negatively interfering with their growth and development. As a result of these effects, knowing species that tolerate this adverse salinity condition is fundamental, both from an environmental aspect and from a scientific point of view. Objective: This research aimed to verify the effects of salinity on the growth and accumulation of organic solutes of Cnidoscolus quercifolius seedlings. Method: The treatments consisted of five levels of NaCl (0, 50, 100, 200 and 400 mM), distributed in entirely randomized design, with four replications. The seedlings grew in ‘Leonard’ pots, containing washed sand and nutrient solution, kept under saline conditions for 60 days. The parameters analyzed were height; stem diameter; roots, stem, leaves, shoot, and total dry mass; and amino acids, proteins and total soluble sugars content. Results and discussion: Salinity reduced linearly all parameters evaluated, especially at the highest levels of salt in the medium, indicating that the C. quercifolius seedlings were intolerant to the imposed salinity, not being able to adjust osmotically. Research implications: Possibility of revegetation of areas with saline soil problems, reintegrating them into the production system. Originality/value: To know the forest species capable of surviving in areas affected by salinization, enabling the adoption of recovery techniques and practices.

Potential Role of Biochar and Silicon in Improving Physio-Biochemical and Yield Characteristics of Borage Plants under Different Irrigation Regimes.

Silicon (Si) and biochar (Bc) are key signaling conditioners that improve plant metabolic processes and promote drought tolerance. However, the specific role of their integrative application under water restrictions on economical plants is not yet well understood. Two field experiments throughout 2018/2019 and 2019/2020 were conducted to examine the physio-biochemical modifications and yield attributes of borage plants mediated by Bc (9.52 tons ha-1) and/or Si (300 mg L-1) under different irrigation regimes (100, 75, and 50% of crop evapotranspiration). Catalase (CAT) and peroxidase (POD) activity; relative water content, water, and osmotic potential; leaf area per plant and yield attributes; and chlorophyll (Chl) content, Chla/chlorophyllidea (Chlida), and Chlb/Chlidb were considerably reduced within the drought condition. On the other hand, oxidative biomarkers, as well as organic and antioxidant solutes, were increased under drought, associated with membrane dysfunction, superoxide dismutase (SOD) activation, and osmotic adjustment (OA) capacity as well as a hyperaccumulation of porphyrin intermediates. Supplementation of Bc and Si lessens the detrimental impacts of drought on several plant metabolic processes associated with increasing leaf area and yield attributes. Their application under normal or drought conditions significantly elicited the accumulation of organic and antioxidant solutes as well as the activation of antioxidant enzymes, followed by lessening the formation of free radical oxygen and mitigating oxidative injuries. Moreover, their application maintained water status and OA capacity. Si and/or Bc treatment reduced protoporphyrin, magnesium-protoporphyrin, and protochlorophyllide while increasing Chla and Chlb assimilation and boosting the ratio of Chla/Chlida and Chlb/Chlidb, resulting in a rise in leaf area per plant and yield components following these modifications. These findings highlight the significance of Si and/or Bc as (a) stress-signaling molecule(s) in regulating defensive systems in drought-affected borage plants by boosting antioxidant aptitude, regulating water status, and accelerating chlorophyll assimilation, thus leading to increasing leaf area and productivity.

Factors Impacting Rhizobium-legume Symbiotic Nitrogen Fixation with the Physiological and Genetic Responses to Overcome the Adverse Conditions: A Review

Symbiotic N2 fixation is essential for the plant’s growth because it can fix reactive nitrogen compounds in soil. However, all steps of this process can be hampered by several biotic and abiotic environmental factors. This study mainly focused on discussing the impacts of 12 major factors on this process by reviewing the significant numbers of research works. According to the information from these works, we found some significant physiological and genetic impacts caused by these factors like plasmid deletion, genomic mismanagement, abnormal molecular signals, toxicity, deficiency of minerals, deformation of rhizobial cells, protein denaturation, nucleic acid damage, acetylene reduction and nod factors limitation. Furthermore, expression of heat or acid shock proteins, internal buffering, genes spanning, extracellular immobilization, periplasmic allocation, change of lipopolysaccharides composition, intracellular accumulation of inorganic and organic solutes (Osmolyte) and activation of hydrogenase expression are shown by both micro and macro symbionts as a natural response to adapt to these stress conditions. Though the stress-tolerant strains like HR-3, HR-6, HR-10, HR-12, acta, actP, exoR, lpiA, actR, actS and phrR can be used to sense the external environment and make signals to change gene transcription during the adverse condition, the application of genetic engineering should be expanded more to promote the commercial inoculation by the production of novel stress-tolerant strains or modified genes of rhizobia and legumes.

Molecular and physiological responses of Egeria densa under salt stress

Egeria densa (Planch) Casp. (Large-flowered waterweed or Brazilian waterweed; Hydrocharitaceae) is a submerged aquatic plant species used as a bioindicator for freshwater quality. However, there is dearth of fundamental knowledge regarding the response of E. densa to salt stress. Expression level of antiporters EdNHX1 and EdVHA, accumulation of inorganic and organic solutes, and physiological changes in E. densa under NaCl salt shock for 7 days were evaluated. Relative expression level of EdNHX1 and EdVHA was high after 24 h of exposure to 50 and 150 mM NaCl. A positive relation between relative expression level of vacuolar EdNHX1 and EdVHA was observed (R2 = 0.76). Enrichment of Na+ in shoots was dependent on the degree of NaCl concentration and exposure period, leading to elevated Na+/K+ ratio. Free proline was increased by 100 and 150 mM NaCl over the control in each salt exposure time and peaked (19.4 μmol g−1 DW) at 5th day under 150 mM NaCl treatment. Chlorophyll a and chlorophyll b pigments in the leaf tissues of plants under 150 mM NaCl treatment for 5, and 7 days displayed a non-significant change, therefore maximum quantum yield of PSII (Fv/Fm) and photon yield of PSII (ΦPSII) were diminished. Na+ secretion into vacuolar organelles of E. densa was reported for the first time using a comparative study of expression level of vacuolar EdNHX1 and EdVHA, organic and inorganic enrichment, and physiological adaptation under short-term NaCl treatment. The results suggest that E. densa can tolerate very low salt concentrations (<100 mM NaCl); however, this needs to be validated under the natural estuarine environment.

Effect of selenium accumulation on foraging behavior of pollinators and seed yield in Trifolium alexandrinum L.

Selenium (Se) is an essential nutrient for both plants and animals and is usually provided as a supplement to livestock. Se bioaccumulation promotes plant growth by enhancing the accumulation of organic solutes and the activation of antioxidant system. In animals, the Se supplements reduce the chances of mastitis and white muscle disease, and improve the immunity, health, and reproduction, particularly in lactating dairy cows. Therefore, the enrichment or biofortification of fodder crops with Se may improve the nutritional quality of forages and thereby reduce malnutrition in cattle. However, Se hyper-accumulation in plants or plant parts can cause direct toxic effects on insects especially bees. Berseem is a highly cross-pollinated fodder crop that attracts a large number of pollinators. However, little or no reports are available regarding the effects of Se biofortification on the foraging behavior of pollinators in berseem. Therefore, the current study was planned to evaluate the effect of exogenous application of Se on the foraging behavior of native pollinators visiting the berseem crop. Five different doses of Se were applied to evaluate its effect on abundance, foraging behavior (visit duration and visitation rate), and single-visit efficacy of native pollinators that may affect berseem seed yield. Our results showed maximum abundance of pollinators in plants supplemented with low Se level, i.e., 5gha-1 while the minimum abundance was observed at high Se doses (15 and 20gha-1). Also, the seed yield attributes, i.e., the number of seeds per head, seed weight per head, 1000 seed weight, were the highest in plants treated with a low dose of Se, whereas the seed yield of berseem decreased with an increase in Se concentrations. Hence, our study provides evidence that high doses of Se negatively affect the foraging behavior of pollinators (visitation rate and visit duration) in plants. We conclude that the application of moderate Se dose positively influences the pollination ecology of berseem, consequently improving seed yield. HIGHLIGHTS: Selenium (Se) is essential for animals and beneficial for plants and may become toxic at high level. Se is delivered to the environment due to agriculture. Se toxicity affected berseem growth and considerably reduced the seed yield. High dose of Se reduced the abundance of pollinators and negatively affected their foraging behavior.

Castor bean cake increases osmoprotection and oil production in basil (Ocimum basilicum) under saline stress

Water salinity is a major abiotic stress that impacts plant growth and metabolism, reducing crop production. However, the adequate use of organic fertilizers rich in nitrogen (N) can attenuate the damages caused by saline stress. In this context, the castor bean cake (CBC), a co-product of the castor oil production chain, has shown great potential as organic fertilizer and stress mitigator, however, the mechanisms involved in these responses remain unclear. Thus, this study aimed to investigate the effects of different doses of CBC and electrical conductivities of irrigation water (EC) on the photochemical efficiency of photosystem II, the accumulation of organic solutes, and the oil production in basil. The experimental design was randomized blocks in a 5 × 5 factorial scheme, combining levels of EC (0.5, 1.2, 3.0, 4.7, 5.5 dS m−1) with doses of CBC (0.0, 1.4, 5.0, 8.5 and 10 t ha−1), in a matrix generated by the Box Central Compound. The contents of proline, glycine-betaine, proteins, amino acids, reducing sugars, non-reducing sugars, total sugars, photosynthetic pigments, electrolyte leakage, chlorophyll a fluorescence, and oil production were evaluated. The highest photochemical efficiency and oil content was found in basil irrigated with EC up to 3 dS m−1 and supplemented with 5 t ha−1 of CBC, which was followed by lower electrolyte leakage. In addition, CBC induced osmoregulation under saline conditions, as shown by the increase in free amino acids, proteins, proline, glycine-betaine, and sugars. However, high doses of CBC combined with high EC reduced photosynthetic pigment content, chlorophyll a fluorescence, and oil content. In conclusion, CBC induced osmoprotection, maintaining cell membrane integrity and increasing photochemical efficiency of basil. In addition, the use of 5 t ha−1 of CBC combined with low levels of water salinity can be employed to enhance oil production in basil.

English

This study focused on the improving effect of external application of calcium and potassium on growth, ions and organic solutes accumulation in tossa jute plants grown under salt stress. Young plants were subjected in pots to ten treatments including the control without NaCl, 120 mM NaCl and a combination of 120 mM NaCl and an addition of 40 or 60 mM CaSO4, CaCl2, K2SO4 or KNO3. Plant growth, sodium, potassium, proline and soluble sugars contents were determined after two weeks. Results revealed that only the external application of CaSO4 and K2SO4 at 40 mM significantly improved the growth reduction induced by NaCl followed by CaCl2; whereas at 60 mM, only CaSO4 induced similar changes in plant growth. Only, the exogenous application of calcium at 40 mM induced a significant decrease (p&lt;0.05) in the Na+ content and a significant increase (p&lt;0.001) of the K+/Na+ ratio of leaves in comparison with salt stressed plants, while the two forms of calcium and K2SO4 induced a significant increase (p=0.05) in the K+ content. CaSO4 had the best improving effects on plants growth under salt stress, followed by K2SO4 and CaCl2 at 40 mM. This improving effect is due to a better exclusion of Na+ from the leaves, the maintenance of a high ionic selectivity ratio K/Na and/or a better accumulation of K+. &nbsp; Key words: Corchorus olitorius, sodium, potassium, calcium sulphate, calcium chloride, potassium sulphate, potassium nitrate, proline, soluble sugars.&nbsp

Synthesizing glycine betaine via choline oxidation pathway as an osmoprotectant strategy in Haloferacales

The accumulation of organic compatible solutes, such as glycine betaine, is one of the osmoprotective strategies used by halophilic archaea to adapt to high salinity. The uptake of glycine betaine from the external environment using various transporters has been widely studied in different halophilic archaea. However, the de novo biosynthesis of glycine betaine and its distribution in halophilic archaea remain unclear. In this study, an extremely halophilic archaea strain, named Halorubrum sp. 2020YC2 and previously isolated from a salt-lake sample, was identified with complete choline oxidation pathway genes. Halorubrum sp. 2020YC2 could synthesize and accumulate 1.56–4.25 μmol per mg of protein of glycine betaine in a defined medium, with its content increasing along with increasing salinity. The intracellular content of glycine betaine remained relatively stable at different salinities when another exogenous solute such as trehalose was provided. The metabolic profile and transcriptional results strongly suggested that the intracellular glycine betaine was derived from serine, which came from the glycolytic intermediate 3-phosphoglycerate when glucose was used as the sole carbon source. Out of 205 available genomes of halophilic archaea, genes encoding the choline oxidation pathway were identified in 30 genomes, and more than half of the strains belonging to order Haloferacales contained the choline oxidation pathway. Phylogenetic analysis further indicated that this pathway evolved from halophilic Proteobacteria, and its absence in some genera indicated a possible gene loss event during evolution. The analysis of reported culture data of halophilic archaea strains eventually demonstrated that the presence of the choline oxidation pathway had no significant effects on the adaptation of Haloferacales to high salinity habitats. Therefore, the de novo biosynthesis of glycine betaine via the choline oxidation pathway could be an auxiliary osmoprotective strategy in halophilic archaea.

Response of African Basil (Ocimum gratissimum L.) to Salt Stress under Tropical Conditions in the Republic of Benin: Growth, Ions and Organic Solutes Accumulation

Aims: This research aims at evaluating the effect of salt stress on plant growth, Na+, K+, proline and soluble sugars contents in leaves and roots of local cultivar of African basil in Republic of Benin.&#x0D; Study Design: The experiment was laid out in a Completely Randomized Design (CRD) having five treatments and three replications.&#x0D; Place and duration of Study: The experiment was carried out in screening house under natural conditions at the Center of Agricultural Research of Agonkanmey, Commune of Abomey-Calavi, Republic of Benin from January to February, 2020.&#x0D; Methodology: Five salt concentrations (0, 30, 60, 90 and 120 mM) were used to irrigate three weeks old plants for two weeks. After two weeks, plant growth, sodium (Na) and potassium (K), proline, and soluble sugars contents of leaves and roots were determined.&#x0D; Results: Salt stress induced a significant reduction (p = .05) in shoot growth from 60 mM NaCl but had no impact on the number of leaves and shoot water content. Root growth was significantly reduced (p = .05) already at 30 mM NaCl. Leaf and roots Na+, proline and soluble sugars contents significantly increased (p = .05) under salt stress whereas K+ content decreased significantly (p = .05) only in root.&#x0D; Conclusion: Salt stress reduces the growth of African basil plants due mainly to Na+ ion toxicity. The ionic selectivity ratio (K+/Na+) rather than the K+ ion content plays an important role in the response of basil plants to salt stress, while both proline and soluble sugars accumulation may contribute to osmotic adjustment.

Effect of Drought Stress on Physio-biochemical Traits and Secondary Metabolites Production in the Woody Species Pinus Halepensis Mill. At a Juvenile Development Stage

ABSTRACT The characterization of the drought stress responses of plants is essential to understand the interactions of these effects with key life processes, such as growth and reproduction. The capability of plants to respond to abiotic stress is associated with their plasticity as well as the adaptableness of plant traits to fluctuating bioclimatic conditions. In this study, the response of Pinus halepensis seedlings to the different water irrigation regimes was assessed based on various ecophysiological, biochemical, and metabolic traits. This approach aims to identify different traits capable of predicting the ability of formerly uncharacterized seedlings to cope with drought stress. The obtained results revealed that drought stress affects the vital metabolic processes in Aleppo pine plants, such as transpiration, photosynthesis, and respiration at their early development stage. These variations were accompanied by changes in chlorophyll pigment contents and an accumulation of organic solutes (sugar and proline). Both drought stress levels induced an increase over the control of the amounts of total secondary metabolites and essential oil contents. These findings are of particular interest in the comprehension of seedlings response to drought stress which provides valuable background knowledge for the success of reforestation programs based on this woody species.

Use of hydrogel in the irrigation management of white pitaya (Hylocereus undatus) seedlings: Biometrics and accumulation of organic and inorganic solutes

The initial development of pitayas may be limited by a few factors, among them, water deficit. Agricultural hydrogels can be used as an alternative to enhance the retention and availability of water and nutrients in the soil. Therefore, this study aimed to evaluate the influence of irrigation frequency and hydrogel doses on the development of white pitaya (Hylocereus undatus) seedlings to establish a time interval in days between irrigations that provides better seedling development and determine the hydrogel dose that provides a reduction of water consumption without damaging seedling development. The experimental design consisted of randomized blocks in a 4 x 4 factorial arrangement, in which the treatments corresponded to 4 hydrogel doses (0, 2, 4, and 6 g/plant of Biogel Hidro Plus) incorporated into the substrate and four irrigation frequencies (1, 3, 5, and 7 days of interval). The biometric characteristics, photosynthetic pigments, and organic and inorganic solutes of the plants were evaluated after 120 days. The use of daily irrigation negatively influenced the growth and biomass accumulation of the aerial part of the seedlings and, consequently, provided the lowest values of cladodes of the pitaya seedlings. Pitaya seedlings had greater development when using an irrigation frequency of around 3 days. The application of 6 g/plant of hydrogel provided the highest averages for accumulation of dry biomass, photosynthetic pigments, and organic and inorganic solutes at irrigation levels of 3.6, 4, and about 3.8 days of intervals, respectively. Hydrogel incorporation allowed increasing the interval between irrigations by 1 day without damages to the seedling development.

Physiological responses of Triplaris gardneriana Wedd. seedlings (Polygonaceae) under intermittent drought

Triplaris gardneriana Wedd is a deciduous riparian tree occurring in areas with different climatic conditions in Brazil, from the rainforest to the tropical dry forest. An increase in global temperature and drought events can change the growth pattern and establishment of the species. To evaluate the effects of intermittent drought on the growth of T. gardneriana seedlings, an experiment was performed using seedlings with one month old subjected to three water treatments (daily irrigation as control, and intermittent drought through cycles of water suppression of seven (S7) and 14 days-intervals (S14) between watering. Growth, biomass production and partitioning, relative water content (RWC), the accumulation of organic solutes, protoplasmic integrity and phenotypic plasticity index (PPI) were evaluated for a better understanding about its drought tolerance level. Intermittent drought severely affected plants growth in S14 plants, showing lower plant height, number of leaves, leaf area, and dry biomass. RWC was reduced, while carbohydrates and proline contents increased in response to drought stress. Protoplasmic damage increased electrolyte leakage in plants subjected to severe stress. However, T. garderiana demonstrated moderate tolerance to water deficit. The plastic changes observed were more physiological than morphological. Therefore, T. gardneriana seems to be a moderately tolerant species to intermittent drought.

Seed priming improves Salvia hispanica L. seed performance under salt stress

Salvia hispanica L. is an alternative crop cultivated by farmers who want to diversify their production. However, this species is sensitive to salinity, which affects its germination negatively. Seed priming with different attenuators is a technique with potential to mitigate the effects of salt stress. Thus, the objective of this study was to evaluate the effect of seed priming with the use of different attenuators on the germination, growth, and organic solute accumulation of S. hispanica seedlings under salt stress. The experimental design was completely randomized, with treatments distributed in a 4 × 5 factorial scheme, corresponding to four seed priming treatments and five osmotic potentials, with four replicates of 50 seeds in each treatment. The seed treatments consisted of presoaking seeds for 4h in salicylic acid, gibberellic acid, and distilled water and the control treatment, which did not involve soaking. These seeds were germinated at osmotic potentials of 0.0, -0.1, -0.2, -0.3, and -0.4 MPa, using NaCl as an osmotic agent to simulate the different salinity levels. Among all the treatments implemented, S. hispanica seed priming with salicylic acid was the most efficient in mitigating the salt stress effects.

Growth and organic solutes accumulation in seedlings of Caatinga tree species in response of water deficit and potassium

Drought stress negatively influences a variety of essential physiological process for plant growth and biomass production, and potassium contributes to the absorption of water and maintaining cell turgor, being crucial to understand the seedlings water stress responses. This research aimed to verify the effects to water deficiency and potassium on the growth and accumulation of organic solutes in Myracrodruon urundeuva, Libidibia ferrea, and Mimosa tenuiflora. The treatments were distributed in a 3 x 3 factorial scheme, with three water levels (100%pc - control, 50%pc - moderate water deficit, and 25%pc - severe water deficit) and three doses of potassium (0, 97.5 and 195 mg dm-3 K). The plants were sown in black plastic bags, containing 5 kg of soil. Were evaluated plant height, stem diameter, and leaf concentrations of total soluble sugars, total free amino acids, and proteins. The water deficit caused a reduction in the growth of M. urundeuva and M. tenuiflora plants, regardless of the added potassium. The plants of M. urundeuva and M. tenuiflora were not demanding in potassium, while potassium fertilization with 97.5 mg dm-3 K favored L. ferrea plants, especially when kept under moderate water deficit. The moderate water deficit promoted accumulation of total free amino acids and soluble proteins in M. urundeuva, while in L. ferrea there was accumulation of total free amino acids under severe water deficit. Increase in the potassium promoted reduction in the concentrations of total soluble sugars and soluble proteins.

Photosynthetic Gas Exchange and Chlorophyll a Fluorescence in Salicornia brachiata (Roxb.) Under Osmotic Stress

Osmotic stress negatively affects the photosynthetic efficiency and cause a significant loss of crop productivity. Salicornia brachiata (Roxb.) is a eu-halophyte. We hereby report on photosynthetic gas exchange and chlorophyll fluorescence in S. brachiata under sodium chloride (NaCl), seawater and polyethylene glycol (PEG) induced osmotic stress. It grows luxuriantly and exhibited a higher tolerance index and better accumulation of organic solutes under 100% strength of seawater (32.5 ppt) and 0.5 M NaCl salinity. It exhibited comparatively better gas exchange, stomatal conductance, PSII photochemistry and electron transfer under 100% strength of seawater salinity. Higher chlorophyll a/b ratio under stress conditions indicated a lower ratio of PSII to PSI and balanced excitation of PSI and PSII in S. brachiata resulting in efficient photosynthetic processes. The lower total chlorophyll/carotenoids ratio and higher non-photochemical quenching indicated the photo-protection and safer dissipation of heat energy in S. brachiata under stress. The 100% strength of seawater and 0.5 M NaCl salinity in S. brachiata did not cause significant changes in antenna size, connectivity between PSII reaction centres (RCs) and reduction of electrons on PSII donor side. The 20% PEG induced the inactivation of RCs and cause damage to PSII RCs in S. brachiata thus reduced the electron transfer from QA– to QB pool-sized and activity of water-splitting complex. Higher φ(P0) and FV/FM in S. brachiata under seawater salinity indicated a comparatively better quantum yield of primary photochemistry. The higher PITotal in S. brachiata under 100% strength of seawater and 0.5 M NaCl stress indicated a better energy flux reaching to PSII RCs, electron transport and performance of RCs. The higher strengths of osmotic stress cause reduction in the quantum yield of PSII electron transport and capturing efficiency of excitation energy by open PSII RCs in S. brachiata.

Arbuscular mycorrhizal fungi mediated salt tolerance by regulating antioxidant enzyme system, photosynthetic pathways and ionic equilibrium in pea (Pisum sativumL.).

Arbuscular mycorrhizal (AM) fungi play an important role in improving the plant tolerance to salt stress. In the present study, we investigated the influence of AM fungi inoculation on various physiological, biochemical and nutritional aspects of pea grown under salt stress. The AM fungi inoculation successfully reduced the negative effects of salinity by improving the antioxidant enzyme system, a greater accumulation of compatible organic solutes, a higher content of photosynthetic pigment and a balanced uptake of nutrients, which resulted in higher growth and yield. Seed yield was found to be significantly higher by ~ 24, 40 and 54% in T2 (Rhizoglomusintraradices), T3 (Funneliformis mosseae and R. intraradices) and T4 (Rhizoglomus fasciculatum and Gigaspora sp.), respectively, as compared to nonmycorrhizal plants. Overall, a mixed application of Rfasciculatum and Gigaspora sp. was superior to other mycorrhizal treatments, which can be attributed to specific compatibility relationships or functional complementarity that exists between symbionts.

Expanded hemodialysis: new opportunities and hopes

In the field of hemodialysis technologies, as in other fields of medicine, evolutionary changes are constantly taking place. The innovations are driven by unachieved clinical outcomes and desire to improve the quality of care of patients with CKD 5D. Recent advances in dialysis techniques resulted in the possibility to expand the permeability of dialysis membranes for a wider spectrum of uremic toxins that lead to the enhancement of long-term outcomes improving quality of life and reducing the mortality rate of dialysis patients. The inadequacy of existent dialysis techniques, at least in part, is due to the chronic accumulation of organic retention solutes of middle and large molecules, which are poorly or even not removed during dialysis.&#x0D; A gradual improvement in the elimination of uremic toxins is observed as a result of the development of new alternative approaches of hemodialysis therapy, such as high-flux hemodialysis, hemodiafiltration, expanded hemodialysis (HDx). However, some techniques have had limited success due to a host number of organizational, technological, financial and human factors. Expanded hemodialysis offers a novel blood purification technology in removal of the large spectrum of uremic toxins, in particular large medium molecules, due to the new structure of the dialysis membrane. There are a number of studies that prove the potential benefits of a new method of dialysis therapy over the previous ones, suggesting a reduction in cardiovascular mortality, vascular calcification and inflammation. In addition, there is evidence of a positive effect of HDx on the quality of life in dialysis patients. In particular, to minimize the manifestations of skin itching, restless legs syndrome, asthenic syndrome.

Adaptive responses of millet (Pennisetum glaucum) and elephant grass (Pennisetum purpureum) at salinity

The Northeast region of Brazil is most affected by the reduction in water availability, contributing directly to the accumulation of salts at the soil surface. Therefore, this study aimed to evaluate the adaptive responses of Pennisetum glaucum and Pennisetum purpureum submitted to salinity. Seeds of two gramineous species, submitted to the saline treatment of 60 mM NaCl, were used in the nutrient solutions. K + absorption, accumulation of organic solutes and ions were measured as tolerance indicators. The experimental design was completely randomized, in a factorial 2x2 scheme ( P. glaucum and P. purpureum and two control treatments and saline stress). The soluble carbohydrate content as a response to salinity had a greater effect on P. purpureum plants grown in solution. Regard to the stress, the species that most stood out was P. purpureum , presenting a lower accumulation of salts, and increasing the carbohydrate content in the plant tissues, making the P. purpureum plants have a tolerance greater than P. glaucum .