Plants Solanum Tuberosum Research Articles

Effect of linear alkylbenzene sulfonate on the uptake of microcystins by Brassica oleracea and Solanum tuberosum.

Globally, hypereutrophic conditions in major water reservoirs used for irrigation purposes, promote the co-existence of cyanotoxins and other pollutants such as linear alkylbenzene sulfonate (LAS). LAS is known to alter the permeability of membranes and promote the uptake of other pollutants by plants. In light of the potential human health risks and prevailing hypereutrophic conditions in some catchments in South Africa, we investigated the combined effects of LAS and microcystins (MCs) on food plants when cyanobacteria infested water is used to irrigate terrestrial crops. To understand the potential risks, pot-culture experiments were conducted to assess the effect of LAS on the accumulation of MCs in Brassica oleracea (cabbage) and Solanum tuberosum (potato) plants. The plants were watered with dam water containing 3.48 mg L -1 of the LAS (sodium dodecyl sulfate) and MCs (MC-LR: 10.47 ± 3.879; 6.158 ± 4.127 for MC-RR and 8.160 ± 2.544 for MC-YR μg L -1) for 20 days. The presence of LAS, at environmentally relevant concentrations in the irrigation water, did not enhance the uptake of MCs in the two plants, as demonstrated by statistically insignificant differences in the means of the treatments (with and without LAS). In addition, the presence of LAS, high pH, electrical conductivity (EC), and cyanotoxins in the water did not affect the total chlorophyll or the well-being of the plants. However, in some cases the levels of MCs bioaccumulated by the two plants exceeded the WHO recommended tolerable daily intake (TDI). These findings imply that the tested levels of LAS and MCs did not have any synergic effects on the two plant species, but irrigating food crops with such water still poses a human health risk.

НОВЫЕ ВОЗМОЖНОСТИ ЛЕЧЕНИЯ И ПРОФИЛАКТИКИ ИНФЕКЦИОННО-ВОСПАЛИТЕЛЬНЫХ ЗАБОЛЕВАНИЙ РЕСПИРАТОРНОГО ТРАКТА

Management of patients with infectious and inflammatory diseases of the upper respiratory tract is one of the most pressing problems of modern medicine, which is associated with the widespread prevalence of this pathology. The main causative agents of acute respiratory infections (ARI) are viruses, but the frequency of unjustified prescription of antibiotic therapy remains high. Despite significant advances in healthcare, questions of the effectiveness and safety of treatment of patients with ARI and the prevention of complications remain largely open to the present day. In this aspect, the possibility of using the original domestic antiviral drug of plant origin Panavir® in respiratory medicine is of particular interest to doctors and patients. The action of Panavir® is aimed at increasing the body’s resistance to the effects of pathogens and the production of interferons - protective proteins produced by the body in response to pathogen invasion. Panavir® is a biologically active polysaccharide obtained from the plant Solanum tuberosum (tuberous nightshade). This substance has a long-term protective effect, prevents the development of inflammation, and accelerates the restoration of the mucous membrane.

Efficiency of the alpha-hairpinin SmAMP-X gene promoter from Stellaria media plant depends on selection of transgenic approach.

The antimicrobial activity of the alpha-HAIRPININ ANTIMICROBIAL PEPTIDE X (SmAMP-X gene, GenBank acc. No. HG423454.1) from Stellaria media plant has been shown in vitro. Here, we isolated the SmAMP-X gene promoter and found two genomic sequences for the promoter (designated pro-SmAMP-X and pro-SmAMP-X-Ψ2) with 83% identity in their core and proximal regions. We found that the abilities of these promoters to express the uidA reporter and the nptII selectable marker differ according to the structural organization of T-DNA in the binary vector used for plant transformation. Analysis of Agrobacterium-infiltrated Nicotiana benthamiana leaves, transgenic Arabidopsis thaliana lines, and transgenic Solanum tuberosum plants revealed that both promoters in the pCambia1381Z and pCambia2301 binary vectors generate 42-100% of the ß-glucuronidase (GUS) activity generated by the CaMV35S promoter. According to 5'-RACE (rapid amplification of cDNA ends) analysis, both plant promoters are influenced by the CaMV35S enhancer used to express selectable markers in the T-DNA region of pCambia1381Z and pCambia2301. The exclusion of CaMV35S enhancer from the T-DNA region significantly reduces the efficiency of pro-SmAMP-X-Ψ2 promoter for GUS production. Both promoters in the pCambia2300 vector without CaMV35S enhancer in the T-DNA region weakly express the nptII selectable marker in different tissues of transgenic N. tabacum plants and enable selection of transgenic cells in media with a high concentration of kanamycin. Overall, promoter sequences must be functionally validated in binary vectors lacking CaMV35S enhancer.

The effect of the linear alkylbenzene sulfonate, sodium-dodecyl-sulfonate (SDS), on the bioaccumulation of Al, Sr and Mn by Brassica oleracea and Solanum tuberosum

The hyper-eutrophic conditions in impoundments used for irrigation around South Africa’s major cities promote the co-existence of linear alkylbenzene sulfonate (LAS) and other pollutants such as metals. The combined effects of LAS and metals, when such water is used to irrigate crops, has not been properly investigated in light of human health risks and prevailing local conditions. To understand the potential risks, pot-culture experiments were conducted to assess the effect of the LAS, sodium-dodecyl-sulfonate (SDS), on the accumulation of aluminum (Al), manganese (Mn) and strontium (Sr) in Brassica oleracea (cabbage) and Solanum tuberosum (potato) plants. The plants were watered with dam water containing 3.48 mg‧L−1 of the LAS (sodium dodecyl sulfonate) and Mn (0.257 mg‧L−1), Al (0.6 mg‧L−1) and Sr (0.16 mg‧L−1) as determined by field surveys, for 20 days. The presence of SDS in the irrigation water at environmentally relevant concentrations did not enhance uptake of Sr, Mn, Al in the two plants, as demonstrated by statistically insignificant differences in the means of the treatments (with and without SDS). In addition, the presence of the metals, high pH, EC and presence of cyanotoxins in the water did not affect total chlorophyll and growth of the plants. These findings imply that the prevailing levels of anionic surfactants such as SDS, metals and other contaminants in the hyper-eutrophic reservoirs pose little risk to crop yields, quality of crops and human health, due to the possible accumulation of these contaminants in irrigated plants. Despite the study reporting no immediate inherent risk to the plants and human health, continuous monitoring of the contaminants in water, soil and irrigated plants is recommended since the conditions, concentrations and other factors can quickly change if the management of the catchment does not improve in the near future.

Six Unprecedented Cytochalasin Derivatives from the Potato Endophytic Fungus Xylaria curta E10 and Their Cytotoxicity.

Six previously undescribed cytochalasins, Curtachalasins X1-X6 (1-6), together with six known compounds (7-12) were isolated from the endophytic fungus Xylaria curta E10 harbored in the plant Solanum tuberosum. The structures were elucidated by the interpretation of HRESIMS, UV, and NMR data. The absolute configurations of Curtachalasins X1-X6 were determined by comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. In bioassays, Curtachalasin X1 (1) and X5 (5) showed cytotoxic activity against the MCF-7 cell line with IC50 values of 2.03 μM and 0.85 μM, respectively.

Plant genetic relatedness and volatile-mediated signalling between Solanum tuberosum plants in response to herbivory by Spodoptera exigua

It has been proposed that plant-plant signalling via herbivore-induced volatile organic compounds (VOCs) should be stronger between closely related than unrelated plants. However, empirical tests remain limited and few studies have provided detailed assessments of induced changes in VOCs emissions across plant genotypes to explain genetic relatedness effects. In this study, we tested whether airborne signalling in response to herbivory between Solanum tuberosum (potato) plants was contingent on plant genetic relatedness, and further investigated genotypic variation in VOCs potentially underlying signalling and its contingency on relatedness. We carried out a greenhouse experiment using 15 S. tuberosum varieties placing pairs of plants in plastic cages, i.e. an emitter and a receiver, where both plants were of the same genotype or different genotype thereby testing for self-recognition, an elemental form genetic relatedness effects. Then, for half of the cages within each level of relatedness the emitter plant was damaged by Spodoptera exigua larvae whereas for the other half the emitter was not damaged. Three days later, we placed S. exigua larvae on receivers to test for emitter VOC effects on leaf consumption and larval weight gain (i.e. induced resistance). In addition, we used a second group of plants subjected to the same induction treatment with the same S. tuberosum varieties to test for herbivore-induced changes in VOC emissions and variation in VOC emissions among these plant genotypes. We found that herbivory drove changes in VOC composition but not total emissions, and also observed quantitative and qualitative variation in constitutive and induced VOC emissions among varieties. Results from the bioassay showed that the amount of leaf area consumed and larval weight gain on receiver plants exposed to damaged emitters were significantly lower compared to mean values on receivers exposed to control emitters. However, and despite genotypic variation in induced VOCs, this signalling effect was not contingent on plant genetic relatedness. These findings provide evidence of VOCs-mediated signalling between S. tuberosum plants in response to S. exigua damage, but no evidence of self-recognition effects in signalling contingent on variation in VOC emissions among S. tuberosum varieties.

Effect of linear alkylbenzene sulfonate on the uptake of microcystins by Brassica oleracea and Solanum tuberosum

Background Hypereutrophic conditions in major water reservoirs used for irrigation purposes in South Africa promote the co-existence of cyanotoxins and other pollutants such as linear alkylbenzene sulfonate (LAS). LAS is known to alter the permeability of membranes and promote the uptake of other pollutants by plants. In light of the potential human health risks and prevailing hypereutrophic conditions in some catchments in South Africa, we investigated the combined effects of LAS and microcystins (MCs) when cyanobacteria infested water is used to irrigate terrestrial crops. Methods To understand the potential risks, pot-culture experiments were conducted to assess the effect of LAS on the accumulation of MCs in Brassica oleracea (cabbage) and Solanum tuberosum (potato) plants. The plants were watered with dam water containing 3.48 mg L-1 of the LAS (sodium dodecyl sulfate) and MCs (MC-LR: 10.47 ± 3.879; 6.158 ± 4.127 for MC-RR and 8.160 ± 2.544 for MC-YR μg L-1) for 20 days. Results The presence of LAS, at environmentally relevant concentrations in the irrigation water, did not enhance the uptake of MCs in the two plants, as demonstrated by statistically insignificant differences in the means of the treatments (with and without LAS). In addition, the presence of LAS, high pH, electrical conductivity (EC), and cyanotoxins in the water did not affect the total chlorophyll or the well-being of the plants. However, in some cases the levels of MCs bioaccumulated by the two plants exceeded the WHO recommended tolerable daily intake (TDI). Conclusions These findings imply that the tested levels of LAS and MCs did not have any synergic effects on the two plant species, but irrigating food crops with such water still poses a human health risk.

Biodiversity monitoring as a baseline for PROPER biodiversity protection program of PT. Geo Dipa Energi Dieng, Central Java, Indonesia

Abstract. Hadisusanto S, Purnomo, Trijoko, Reza A, Eprilurahman R, Yudha DS, Sudibyo P, Asti HA, Fauzy NH, Pranoto FS, Priyono DS, Mufti S, Rabbani A, Putri DM, Syamsumin, Tampubolon APC, Abdullah FN. 2022. Biodiversity monitoring as a baseline for PROPER biodiversity protection program of PT. Geo Dipa Energi Dieng, Central Java, Indonesia. Biodiversitas 23: 4466-4472. Anthropogenic activities drove an unprecedented rate of land-use change in the last century. Corporate is one of the most highlighted sectors due to the extent of the impact on the environment. Therefore, PROPER (Corporate Performance Rating Assessment for Environmental Program) was developed by the Ministry of Environment and Forestry as a safeguard to halt biodiversity loss due to corporate-related development in Indonesia. The present study analyzed the flora and fauna composition, structure, and trend in PT. Geo Dipa Energi Dieng well pad surrounding area from 2019-2021, as a critical part of the PROPER assessments. The study revealed that the study area was homogeneously dominated by shrubs-herbaceous plants, contributing to 60% of total species richness and abundance. Two dominant species were the introduced wild species Ageratina riparia and the cultivated plant Solanum tuberosum. Moreover, despite tree individual scarcity, the tree growth form was primarily constituted by introduced species with a mean abundance of 347 individuals, or 5-fold higher than native species. Acacia decurrens and Cupressus sempervirens, the introduced tree species planted during the rehabilitation program, dominated the area. The homogeneous floristic composition led to a homogenization of the fauna community, particularly birds, dominated by cosmopolitan insectivorous species. NMDS analysis and Shannon-Diversity Index also revealed that the pattern and trend among sites and years were similar, and there was an insignificant change, showing the urgency of the long-term revegetation programs to rehabilitate the ecosystem. Moreover, the presence of protected species in the study area showed that ecosystem rehabilitation is critical.

Deep-frying purple potato Purple Majesty using sunflower oil: effect on the polyphenols, anthocyanins and antioxidant activity

The potato is a root vegetable native to the Americas; it consists of the starchy tuber of the plant Solanum tuberosum. There are many varieties, and the flesh can have different colour ranging from yellow to red and purple. Coloured varieties have a denser texture and slightly nuttier, earthier flavour than other potatoes. The desirable quality characteristics of potatoes depends on the intended use, and the acceptability of raw potatoes is determined by size, shape, colour, and the quality of can be evaluated in terms of colour, flavour, and texture. Deep-frying is the century-old and it is among the most common cooking processes, still being used to prepare a variety of food products on both industrial and domestic scales. Frying the potatoes is among the tastiest and appreciated way to cook this vegetable. Purple fleshed potatoes are widely considered one of the best-tasting purple potatoes varieties, they have a nice taste and add colour to a meal. They are a source of beneficial health compounds which makes them interesting as functional food. The anthocyanins present in the Purple Majesty variety are interesting for their health promoting abilities, anti-oxidative activity, and even other health beneficial effects, e.g. anti-influenza virus activity, and anti-stomach cancer activity. The aim of this study has been to assess the effect of deep-frying of purple potato Purple Majesty using sunflower oil on the polyphenols, anthocyanins and to evaluate the antioxidant activity of the cooked matrix compared to the fresh one. The results seem to suggest that the healthy characteristics of this functional food are retained after the cooking by frying.

Gene Downregulation in Potato Roots Using Agrobacterium rhizogenes-Mediated Transformation.

Agrobacterium rhizogenes has the ability to transform plant cells by transferring the T-DNA from the Ri plasmid to the plant cell genome. These infected plant cells divide and organize the formation of adventitious roots, called hairy roots. When the A. rhizogenes is additionally transformed with a binary vector, the cells infected can indeed be transformed with this second T-DNA producing transgenic hairy roots. In this chapter, we present the protocol to produce transgenic hairy roots from in vitro potato (Solanum tuberosum) plants injected with transformed A. rhizogenes, generating plants with a wild-type shoot and a transgenic root system. Specifically, we detail the procedure to obtain in vitro-cultured hairy roots with a downregulated gene of interest, by using a Gateway-based binary vector able to produce a RNA hairpin triggering the RNA interference mechanism (hpRNAi). We also present the protocol to analyze the downregulation of the target gene in hairy roots by means of reverse-transcription reaction followed by real-time PCR (qPCR).

The role of disulfide bonds in a Solanum tuberosum saposin-like protein investigated using molecular dynamics.

The Solanum tuberosum plant specific insert (StPSI) has a defensive role in potato plants, with the requirements of acidic pH and anionic lipids. The StPSI contains a set of three highly conserved disulfide bonds that bridge the protein's helical domains. Removal of these bonds leads to enhanced membrane interactions. This work examined the effects of their sequential removal, both individually and in combination, using all-atom molecular dynamics to elucidate the role of disulfide linkages in maintaining overall protein tertiary structure. The tertiary structure was found to remain stable at both acidic (active) and neutral (inactive) pH despite the removal of disulfide linkages. The findings include how the dimer structure is stabilized and the impact on secondary structure on a residue-basis as a function of disulfide bond removal. The StPSI possesses an extensive network of inter-monomer hydrophobic interactions and intra-monomer hydrogen bonds, which is likely the key to the stability of the StPSI by stabilizing local secondary structure and the tertiary saposin-fold, leading to a robust association between monomers, regardless of the disulfide bond state. Removal of disulfide bonds did not significantly impact secondary structure, nor lead to quaternary structural changes. Instead, disulfide bond removal induces regions of amino acids with relatively higher or lower variation in secondary structure, relative to when all the disulfide bonds are intact. Although disulfide bonds are not required to preserve overall secondary structure, they may have an important role in maintaining a less plastic structure within plant cells in order to regulate membrane affinity or targeting.

The presence of Phytophthora infestans in the rhizosphere of a wild Solanum species may contribute to off-season survival and pathogenicity

We evaluated oomycete presence and abundance in the rhizosphere of wild perennial Solanum species to investigate the presence of plant pathogenic or mycoparasitic species. Furthermore, we investigated whether these plant species could function as hosts, or associated plants, for off-season survival of economically important pathogens. We collected soil samples in Sweden from Solanum dulcamara and as a control from Vitis vinifera over all four seasons of a year, and in New Zealand from Solanum nigrum and Solanum laciniatum in the summer. Species identification, confirmed by ITS and Cox2 sequencing, and root infection assays on the crop plant Solanum tuberosum and on S. dulcamara, suggested the presence of mainly Pythiales species. In Sweden, we also found evidence for the presence of Phytophthora infestans, the causal agent of potato late blight, in the rhizosphere of S. dulcamara. These Ph. infestans isolates had no negative effects on root growth of S. dulcamara in Sweden, but were more pathogenic on potato leaves than a common lab strain. Oomycete diversity measures indicated a high similarity between seasons and countries. In conclusion, our study suggests a previously unknown overwintering strategy for the pathogen Ph. infestans, indicating a possible influence of the wild species S. dulcamara on the epidemiology of potato late blight in Sweden.

Tolerance of potato plants to chloride salinity is regulated by selective light

Compared the response of the plant Solanum tuberosum L. mid-varieties Nakra to chloride salinity which depending on lighting conditions. Regenerated plants were produced in vitro from apical meristem and grown on half-strength Murashige and Skoog medium using a hydroponic unit in controlled-climate conditions. At the age of six weeks, the plants were exposed to salt stress (125 mM NaCl, 7 days); at the same time, plants were grown on white light with red or blue light. Plant response to salt stress was estimated by growth and physiological parameters. Potato plant tolerance to chloride salinity rose after short-term exposure to blue light, which has been first shown in this study. The protective effect of blue light was based on its ability to stimulate the accumulation of low-molecular weight organic compounds with antioxidant activity.

Dynamic pH-induced conformational changes of the PsbO protein in the fluctuating acidity of the thylakoid lumen.

The PsbO protein is an essential extrinsic subunit of photosystem II, the pigment-protein complex responsible for light-driven water splitting. Water oxidation in photosystem II supplies electrons to the photosynthetic electron transfer chain and is accompanied by proton release and oxygen evolution. While the electron transfer steps in this process are well defined and characterized, the driving forces acting on the liberated protons, their dynamics and their destiny are all largely unknown. It was suggested that PsbO undergoes proton-induced conformational changes and forms hydrogen bond networks that ensure prompt proton removal from the catalytic site of water oxidation, i.e. the Mn4 CaO5 cluster. This work reports the purification and characterization of heterologously expressed PsbO from green algae Chlamydomonas reinhardtii and two isoforms from the higher plant Solanum tuberosum (PsbO1 and PsbO2). A comparison to the spinach PsbO reveals striking similarities in intrinsic protein fluorescence and CD spectra, reflecting the near-identical secondary structure of the proteins from algae and higher plants. Titration experiments using the hydrophobic fluorescence probe ANS revealed that eukaryotic PsbO proteins exhibit acid-base hysteresis. This hysteresis is a dynamic effect accompanied by changes in the accessibility of the protein's hydrophobic core and is not due to reversible oligomerization or unfolding of the PsbO protein. These results confirm the hypothesis that pH-dependent dynamic behavior at physiological pH ranges is a common feature of PsbO proteins and causes reversible opening and closing of their β-barrel domain in response to the fluctuating acidity of the thylakoid lumen.

Salicylic Acid-Cryotherapy Treatment for Elimination of Potato Virus S from Solanum Tuberosum

Potato virus S (PVS) is one of the most difficult viruses to eliminate by thermotherapy due to its thermal deactivation point. Pre-treatment methods involving salicylic acid (SA) have been successfully carried in conjugation with cryogenic methods to reduce oxidative damage and eliminate viruses. In the present investigation, the effect of SA to protect Solanum tuberosum plants infected with PVS from oxidative damage from subsequent cryotherapy was studied. Vulnerable genotypes to cryogenic protocol were selected, with two SA treatments examined. Potato clones were pretreated with SA (0, 10−5, and 10−6 M), plant development was evaluated and then exposed to cryotherapy. This was followed up by a plant development evaluation and virus testing. After the initial treatment with SA, the plants exhibited an increase in the variables evaluated before cryotherapy. After cryotherapy, between 66.6% and 100% of the treated plants were found to be virus-free compared to control plants which exhibited 0% survival. Thus, the SA-cryotherapy treatment combination described appears to enhance plant survival and eliminate PVS from potato plants.

Curtachalasins A and B, Two Cytochalasans with a Tetracyclic Skeleton from the Endophytic Fungus Xylaria curta E10.

Two unique cytochalasans, curtachalasins A (1) and B (2), were purified from the endophytic fungus Xylaria curta E10 harbored in the plant Solanum tuberosum. Their structures were determined by extensive spectroscopic methods, X-ray crystallographic analysis, and electronic circular dichroism calculations. These two compounds feature an unprecedented pyrolidine/perhydroanthracene (5/6/6/6 tetracyclic skeleton) fused ring system.

Evaluation of tolerance of tubers Solanum tuberosum to silicа nanoparticles.

In recent years, researches on the impact of nanometals on the state of soil ecosystems, including silicon, which is known to have a positive effect on plants under stressful conditions, have become relevant. The aim of this study was to assess the biological effects of nanoparticles (NP) of SiO2 on the plant Solanum tuberosum. Testing of biological activity of NP SiO2 on potato tubers was carried out on the example of five concentrations of metal increasing exponentially (0.03, 0.09, 0.18, 0.21, and 0.36g/kg of potatoes) and control (without processing of NP SiO2). We have shown that on the 21st day of the experiment after tuber treatment, the average mass of tuber in concentrations 0.18 and 0.21g/kg of NP SiO2 increased by 6.6% and 2.2%, respectively; stimulation of root length by 27.8-21.0%, the length of sprouts increased to 55.3%, and at a concentration of 0.36g/kg on the 14th and 45th days, there was a maximum accumulation of Si in different parts of the plants. Analysis of chlorophyll content in the sprouts Solanum tuberosum showed that concentrations of nanoform SiO2 0.03-0.21g/kg chlorophyll were higher than control by 48.8% and content of carotenoids by 29.7%. According to the results of field studies, the maximum mass of potato stems and tubers was observed at concentrations of 0.09g/kg and 0.18g/kg NP SiO2, which confirmed the absence of toxic properties of NP SiO2. The absence of the toxic effect of the investigated range of concentrations of NP SiO2 from 0.03 to 0.36g/kg was also confirmed by electrophoretic mobility of plant DNA molecules after incubation with silicon nanoparticles in vitro.

Ameliorate the cadmium toxicity in Solanum tuberosum L. plants with selenium and silicon application

The present study aimed to prove the efficiency of Se or Si as relievers of the Cd toxicity in potato plants. Solanum tuberosum plants, Asterix genotype, from in vitro propagation were placed in pots with sand and irrigated with complete nutrient solution for 60 days under six treatments: T1: Control (nutrient solution); T2: 2.5 µM Se; T3: 2.5 mM Si; T4: 50 µM Cd; T5: 50 µM Cd + 2.5 µM Se; T6: 50µM Cd + 2.5 mM Si. The treatments were arranged in completely randomized design, with four replicates for each treatment and six plants per replicate. The plants were collected at 30 and 60 days after application of the treatments. Cadmium was highly toxic in all parameters (dry and fresh weight, plant height, leaf number, leaf area, root and photosynthetic parameters), in both assessments. However, Se and Si were effective in mitigating Cd toxicity in all parameters, although Si has been shown to be more efficient than Se in dry weight and plant height parameters. Thus, from data obtained in this study, it is clear that the beneficial elements tested have power to ameliorate Cd toxicity.

PH dependent membrane binding of the Solanum tuberosum plant specific insert: An in silico study

The Solanum tuberosum plant-specific insert (StPSI) has been shown to possess potent antimicrobial activity against both human and plant pathogens. Furthermore, in vitro, the StPSI is capable of fusing phospholipid vesicles, provided the conditions of net anionic vesicle charge and acidic pH are met. Constant pH replica-exchange simulations indicate several acidic residues on the dimer have highly perturbed pKas (<3.0; E15, D28, E85 & E100) due to involvement in salt bridges. After setting the pH of the system to either 3.0 or 7.4, all-atom simulations provided details of the effect of pH on secondary structural elements, particularly in the previously unresolved crystallographic structure of the loop section. Coarse-grained dimer-bilayer simulations demonstrated that at pH 7.4, the dimer had no affinity for neutral or anionic membranes over the course of 1 μs simulations. Conversely, at pH 3.0 two binding modes were observed. Mode 1 is mediated primarily via strong N-terminal interactions on one monomer only, whereas in mode 2, N- and C-terminal residues of one monomer and numerous polar and basic residues on the second monomer, particularly in the third helix, participate in membrane interactions. Mode 2 was accompanied by re-orientation of the dimer to a more vertical position with respect to helices 1 and 4, positioning the dimer for membrane interactions. These results offer the first examination at near-atomic resolution of residues mediating the StPSI-membrane interactions, and allow for the postulation of a possible fusion mechanism.

Effect of Plant Growth Promoting Rhizobacteria and organic matter on the readiness of soil nutrient, growth and yield of potato plant Solanum tuberosum L

The plant growth promoting rhizobacteria were isolated from the soil of several agriculture fields planted with various crops (Azotobacter chroococcun, Bacillus subtilis, Pseudomonas fluorescens) for the purpose of use with organic matter and knowledge of its impact on the readiness of soil nutrients and growth, yield of potato plant, Three sources of organic matter were used (sheep residues, horse residues, poultry residues). A global experiment was carried out within design of Completely Randomized Block Design RCBD in Radhwaniya south of Baghdad governorate and the results showed the treatment of the mixing of three bacteria species with organic matter in all studied traits was superior as the element concentration Nitrogen, Phosphorus and potash was recorded 63.40 , 18.43 and 163.50 mg.kg-1 soil sequentially and plant height , number of stems , yield was 75.75cm ,3.47stem plant 1 and 30.36 ton hec-1 sequentially .The mixing of three bacterial recorded the highest results in the element concentration was 53.55, 16.25 ,149.00 mg.kg-1 soil and 62.55cm ,2.86 stem plant1 and 23.32 ton hec-1 sequentially. The results showed that concentration of elements increased with the addition of organic matter and reached 61.50, 15.25, 129.33 mg.kg-1 soil and a significant difference from the comparison treatment which recorded the lowest results.