Root Potentials Research Articles

Gene Regulatory Network Guided Investigations and Engineering of Storage Root Development in Root Crops.

The plasticity of plant development relies on its ability to balance growth and stress resistance. To do this, plants have established highly coordinated gene regulatory networks (GRNs) of the transcription factors and signaling components involved in developmental processes and stress responses. In root crops, yields of storage roots are mainly determined by secondary growth driven by the vascular cambium. In relation to this, a dynamic yet intricate GRN should operate in the vascular cambium, in coordination with environmental changes. Despite the significance of root crops as food sources, GRNs wired to mediate secondary growth in the storage root have just begun to emerge, specifically with the study of the radish. Gene expression data available with regard to other important root crops are not detailed enough for us directly to infer underlying molecular mechanisms. Thus, in this review, we provide a general overview of the regulatory programs governing the development and functions of the vascular cambium in model systems, and the role of the vascular cambium on the growth and yield potential of the storage roots in root crops. We then undertake a reanalysis of recent gene expression data generated for major root crops and discuss common GRNs involved in the vascular cambium-driven secondary growth in storage roots using the wealth of information available in Arabidopsis. Finally, we propose future engineering schemes for improving root crop yields by modifying potential key nodes in GRNs.

Nitrogen Fixation and Resorption Efficiency Differences Among Twelve Upland and Lowland Switchgrass Cultivars

In nitrogen (N)-limited terrestrial ecosystems, plants employ various strategies to acquire and conserve N, including translocation of N in perennial tissues and stimulation of N fixation in roots and soils. Switchgrass (Panicum virgatum) is a genotypically and phenotypically diverse perennial grass with two distinct ecotypes (lowland and upland) and numerous genotypes. It grows well in low-N soils, likely because of its ability to translocate N and to associate with N-fixing microbes, but little is known about variation in these traits among cultivars or even ecotypes. We measured N translocation, N fixation potential in roots and soils, soil net N mineralization, soil net nitrification, and biomass yields in 12 switchgrass cultivars grown in a replicated block experiment in southwestern Michigan, United States. Lowland cultivars had higher yields, rates of N translocation, soil net N mineralization, and N fixation potentials on washed, nonsterile roots, while upland cultivars exhibited higher N fixation potentials in root-free soil. N resorption efficiencies averaged 53 ± 5% (± standard error) for lowland versus 29 ± 3% for upland cultivars. Additionally, there were significant among-cultivar differences for all response variables except mineralization and nitrification, with differences likely explained by cultivar-specific physiologies and microbial communities. The ideal cultivar for biofuels is one that can maintain high yields with minimal fertilizer addition, and there appear to be several cultivars that meet these criteria. In addition, results suggest substantial N cycle differences among cultivars that might be exploited by breeders to create new or improved high-yielding, N-conserving switchgrass lines.

Influence of climate variation on phenolic composition and antioxidant capacity of Medicago minima populations

Medicago minima is a pasture legume that grows almost all over the world. In Tunisia, it occupies various climatic environments and is considered the most abundant annual Medicago plant. However, this species is unconsumed and unused by humans. This study aimed to explore the phytochemical characteristics of Medicago minima selected from different provenances in Tunisia and subsequently investigate the influence of environmental factors on their phenolic composition and antioxidant activity. Therefore, a calorimetric method and DPPH tests provided the total phenolic and total flavonoid contents and antioxidant potential in roots, stems, leaves and seeds. High performance liquid chromatography (HPLC) identified and quantified four phenolic acids and three flavonoids in the studied organs. Roots and leaves showed the greatest phenolic compound content and had high antioxidant activity. Rutin and syringic acid (leaves) represent a characteristic for this species. For each organ, principal component analysis of phenolic profiles showed that the root’s phenolic composition could be an indication of the plant adaptation to even small changes in its environments. Plants originating from a cold climate, higher altitude or semi-arid environment had the highest phenolic compound contents in their organs. Our findings provide useful information for the exploitation of the phenolic compounds in these weeds for the development of environmental sustainability.

Irrigation frequency transiently alters whole plant gas exchange, water and hormone status, but irrigation volume determines cumulative growth in two herbaceous crops

Physiological effects of irrigation frequency, at the same irrigation volume, have received little attention but might determine crop yield and water use efficiency. Potted plants of two species, tomato and basil, received two irrigation treatments that both supplied the same irrigation volume (75% of that received by a well-watered treatment—WW), but either frequently (once or twice per day-FDI) or infrequently (every three days-IDI). Stem diameter variations, whole-plant gas exchange, root and leaf water potential, and foliar hormones were monitored for 11 days after applying the treatments, and whole-plant biomass accumulation determined at the end of that period. Treatments showed temporal and spatial differences in soil moisture, with FDI resulting in a wet upper layer and dry lower layer. In both species, water stress integral in IDI was three-fold higher than in FDI, and gas exchange lower than FDI plants. Despite these differences, both treatments accumulated biomass and stem diameter growth similarly. In tomato, IDI induced compensatory stem growth (higher than WW plants) after re-watering, and attenuated hormone accumulation (lower jasmonic, gibberellic, and salicylic acid concentrations than FDI plants) that maintained growth. In basil, stem growth of IDI plants only recovered to WW and FDI levels upon re-watering, but lower sensitivity of stem growth to water deficits explained similar final biomass accumulation to FDI plants. Although both deficit irrigation treatments showed similar cumulative growth, temporal differences in physiological responses suggest that irrigation frequency could be tailored to specific crop species depending on their sensitivity to soil water deficits and re-hydration.

Activation of α-adrenoceptors depresses synaptic transmission of myelinated afferents and inhibits pathways mediating primary afferent depolarization (PAD) in the in vitro mouse spinal cord.

Somatosensory afferent transmission strength is controlled by several presynaptic mechanisms that reduce transmitter release at the spinal cord level. We focused this investigation on the role of α-adrenoceptors in modulating sensory transmission in low-threshold myelinated afferents and in pathways mediating primary afferent depolarization (PAD) of neonatal mouse spinal cord. We hypothesized that the activation of α-adrenoceptors depresses low threshold-evoked synaptic transmission and inhibits pathways mediating PAD. Extracellular field potentials (EFPs) recorded in the deep dorsal horn assessed adrenergic modulation of population monosynaptic transmission, while dorsal root potentials (DRPs) recorded at root entry zone assessed adrenergic modulation of PAD. We found that noradrenaline (NA) and the α1-adrenoceptor agonists phenylephrine and cirazoline depressed synaptic transmission (by 15, 14 and 22%, respectively). DRPs were also depressed by NA, phenylephrine and cirazoline (by 62, 30, and 64%, respectively), and by the α2-adrenoceptor agonist clonidine, although to a lower extent (20%). We conclude that NA depresses monosynaptic transmission of myelinated afferents onto deep dorsal horn neurons via α1-adrenoceptors and inhibits interneuronal pathways mediating PAD through the activation of α1- and α2-adrenoceptors. The functional significance of these modulatory actions in shaping cutaneous and muscle sensory information during motor behaviors requires further study.

Water hyacinth (Eichhornia crassipes) roots, an amazon natural waste, as an alternative biosorbent to uptake a reactive textile dye from aqueous solutions

The effluents generated by the textile industries are potential environmental pollutants due to the presence of toxic dyes. Biosorption is a promising way for the removal of these contaminants from effluents. This technique is preferred when wastes are used as biosorbents. In this sense the use of water hyacinth (Eichhornia crassipes), a macrophyte that causes eutrophication, can be an alternative for dyes biosorption. This work aimed to evaluate the potential of water hyacinth roots as biosorbent for the removal of BF − 4B red reactive dye from aqueous media. In the biosorption kinetic assays, equilibrium time was reached in about 110 min, with 95% of dye removal. Pseudo−second order and Elovich models were adequate to represent the biosorption kinetic profile. The isotherms indicated that the biosorption process is favorable, tending to the Langmuir model with a maximum monolayer biosorption capacity of 43.28 mg g- 1.

Phytotoxicity of Cu2+ and Cd2+ to the roots of four different wheat cultivars as related to charge properties and chemical forms of the metals on whole plant roots.

The relationship between the chemical forms of Cu2+ and Cd2+ adsorbed on the roots of different wheat cultivars and their phytotoxic effects on the plants were investigated. The wheat varieties Dunmaiwang (DMW), Tekang 6 (TK6), Zhongmai895 (ZM895), and Chaojixiaomai (AK68) were used. The zeta potentials of wheat roots, measured by the streaming potential method, were used to characterize root charge properties. Results indicated that the changes in zeta potential at pH 4.01-6.61 were 14.7, 15.53, 13.01, and 12.06mV for ZM895, AK68, DMW, and TK6, respectively. The negative charge and functional groups on ZM895 and AK68 roots were greater than on DMW and TK6 roots, which led to more exchangeable and complexed Cu2+ and Cd2+ on ZM895 and AK68 roots and increased Cu2+ and Cd2+ toxicity compared to DMW and TK6. Coexisting cations, such as Ca2+, Mg2+, K+, and NH4+, alleviated Cu2+ and Cd2+ toxicity to wheat roots through competition for adsorption sites on the roots, which decreased exchangeable and complexed Cu2+ and Cd2+ on wheat roots. The Ca2+ and Mg2+ were most effective in alleviating heavy metal toxicity and they decreased exchangeable Cu2+ on AK68 roots by 39.14% and 47.82%, and exchangeable Cd2+ by 8.51% and 28.23%, respectively.

Oxea to focus on oxo derivatives and speciality chemicals to meet market demand

Physiological effects of irrigation frequency, at the same irrigation volume, have received little attention but might determine crop yield and water use efficiency. Potted plants of two species, tomato and basil, received two irrigation treatments that both supplied the same irrigation volume (75% of that received by a well-watered treatment—WW), but either frequently (once or twice per day-FDI) or infrequently (every three days-IDI). Stem diameter variations, whole-plant gas exchange, root and leaf water potential, and foliar hormones were monitored for 11 days after applying the treatments, and whole-plant biomass accumulation determined at the end of that period. Treatments showed temporal and spatial differences in soil moisture, with FDI resulting in a wet upper layer and dry lower layer. In both species, water stress integral in IDI was three-fold higher than in FDI, and gas exchange lower than FDI plants. Despite these differences, both treatments accumulated biomass and stem diameter growth similarly. In tomato, IDI induced compensatory stem growth (higher than WW plants) after re-watering, and attenuated hormone accumulation (lower jasmonic, gibberellic, and salicylic acid concentrations than FDI plants) that maintained growth. In basil, stem growth of IDI plants only recovered to WW and FDI levels upon re-watering, but lower sensitivity of stem growth to water deficits explained similar final biomass accumulation to FDI plants. Although both deficit irrigation treatments showed similar cumulative growth, temporal differences in physiological responses suggest that irrigation frequency could be tailored to specific crop species depending on their sensitivity to soil water deficits and re-hydration.

Pyrolysis of water hyacinth biomass parts: Bioenergy, gas emissions, and by-products using TG-FTIR and Py-GC/MS analyses

This study aimed to quantify the pyrolytic bioenergy potential of water hyacinth roots (WHR), stems and leaves (WHSL) by assessing their physicochemical properties, pyrolysis performances, kinetics, and thermodynamics. Their gas emissions and other by-products were also detected using thermogravimetry-Fourier transform infrared spectroscopy and pyrolysis–gas chromatography/mass spectrometry analyses. The WHR and WHSL pyrolysis consisted of the three consecutive stages of the moisture removal, devolatilization, and the decomposition of residuals. The main pyrolysis temperature varied between 200 and 600 °C. The elevated heating rate raised both initial devolatilization and peak temperatures and shortened the reaction times of the thermochemical conversions of both samples. According to the comprehensive pyrolysis index, WHSL outperformed WHR. The average activation energy estimates pointed to a lower decomposition cost for WHSL (172.09–173.09 kJ/mol) than WHR (230.11–232.06 kJ/mol). The fluctuating thermodynamic parameters indicated a complicated pyrolysis mechanism for WHR and WHSL. The main gases evolved from the WHR and WHSL pyrolysis in decreasing order were CO2, CO, C–O, SO2, CC, H2O, CH4, and CO. The main pyrolytic by-products were phenols (19.2%), and furans (12.4%) for WHR and nitrides (11.9%), and phenols (10%) for WHSL. Our results provide insights into scaling-up bioenergy potential, value-added by-products, and emission controls based on the pyrolysis of the water hyacinth biomass parts.

Adventitious rooting in stem and rhizome cuttings of Tuscan (Italy) Vaccinium myrtillus L. under different environmental conditions

BACKGROUND: There is no mention in the literature of vegetative propagation of Vaccinium myrtillus. OBJECTIVE: The aim of the study was to evaluate the rooting potential of bilberry rhizome and stem cuttings. METHODS: Rhizome and stem cuttings collected in early Autumn were dipped in different IBA solutions (0 – 2000 – 4000 mgL–1) and rooted in non-sterilized V. myrtillus soil and expanded perlite under controlled growth chamber environment or under mist with basal heating in a greenhouse for 12 weeks. RESULTS: Rhizome cuttings showed high rooting potential in plant growth regulator (PGR) free substrates. Conversely, stem cuttings took advantage from IBA treatments; this positive effect on rooting percentage was synergistically increased when rooted in agriperlite. A higher rooting capacity was achieved when rhizome and stem cuttings were placed in agriperlite, however number of developed roots and shoots were much higher when V. myrtillus turf was used as substrate. Mist and bottom heating did not improve rooting significantly. CONCLUSIONS: V. myrtillus can be successfully propagated both by rhizome and stem cuttings. With an overall rooting success of 56–68% and with a reasonably good growth rate, production of planting material from stem cuttings of V. myrtillus offers opportunities for a cheaper, practically feasible and technically less demanding alternative means of propagation.

Potential of plant roots as traditional medicines of the dayak desa tribe in Pakak, West Kalimantan, Indonesia

The use of plant roots as traditional medicine for Dayak Desa tribe is carried out from generation to generation, but has not been documented properly. This study aims to identify the types of plants used, parts of plants used, and the way they are processed by Dayak Desa tribe, from Kayan Hilir District, Sintang Regency, Indonesia. The survey was conducted in March 2018 and information was collected from the community through interview and field observation. Information was recorded through semi-structured interviews with 100 informants. Data analysis was done by compiling and classifying the medicinal plants based on its family, benefits and how to use them and location from where they were obtained. Then data were documented calculated in term of percentage of families and the percentage of the way to use them. The results showed that twenty five medicinal plants were more commonly belongs to families of Araceae, Fabaceae, and Poaceae with a percentage of 8% each. The most used part of the plant used by Dayak Desa tribe was the roots after with percentage 60%, and are discussed in this manuscript.

Antidiabetic Potential of Prosopis farcta Roots: In Vitro Pancreatic Beta Cell Protection, Enhancement of Glucose Consumption, and Bioassay-Guided Fractionation.

By using the streptozotocin- (STZ-) induced cytotoxicity in β-TC3 cells as an assay model, a bioassay-guided fractionation study was employed to isolate and characterize the potential antidiabetic principles of roots of Prosopis farcta. A combination of open column chromatography on reverse-phase silica gel using a water-ethanol gradient (10 : 90 to 100 : 0) followed by HPLC-based fractionation led to an active compound that appears to be composed of carbohydrate/sugar. When cell viability under STZ was reduced to 49.8 ± 4% (mean ± SD), treatment with the active compound at the concentration of 0.5 mg/mL either as a coadministration or a pretreatment improved the viability to 93 ± 1.9% and 91.5 ± 7%, respectively. The reduction in the mitochondrial membrane potential by STZ (47.34 ± 8.9% of control) was similarly recovered to 84.5 ± 4.3 (coadministration) and 88 ± 5.5% (pretreatment) by the active fraction. The bioassay-guided fractionation, β-cell protective effect, and increased glucose consumption (up to 1.49-fold increase) in hepatocytes by the extracts and active fraction are also discussed.

Эколого-физиологические особенности реакции сосны обыкновенной на уровень плодородия почвы как показатель адаптации к условиям среды

Comprehensive ecological and physiological studies (on the organism level) of plant response of Scots pine to changes in soil fertility were carried out in order to obtain quantitative parameters of the leaf apparatus and root system functioning and nature of their interrelation. Biological productivity was calculated according to V.M. Lebedev and E.V. Lebedev (2006), net productivity of photosynthesis – according to A.A. Nichiporovich (1955), and mineral productivity – according to V.M. Lebedev (1998). The response of 2–3-year-old scots pine plants was studied for fertilization with 30, 60, 120 and 240 kg/ha of nitrogen against the fertilizer application rate of Р60К60 under the conditions of a microfield experiment on gray forest soil. An increase in the level of nitrogen nutrition led to a change in the ecological and physiological parameters of the root system and leaf apparatus functioning: the ratio between root and photosynthetic potential, nitrogen absorption by the unit of the active surface of roots per day, net productivity of photosynthesis, and biological productivity of plants. The nitrogen status slightly affected the net productivity of photosynthesis, however drove up an increase in biological productivity by 1.2–1.5 times. An increase in the nitrogen status led to a change in the ratio between the values of root and photosynthetic potentials in favor of the leaf apparatus. A high positive correlation (0.931–0.992) between the photosynthetic potential and increase in dry mass; and a high negative correlation (–(0.843–0.963)) between the ratio of root potential to photosynthetic potential and nitrogen uptake were established. The maximum of pine biological productivity was observed at a nitrogen rate of 120 kg/ha. A further increase of the nitrogen status led to a decrease in biological productivity and was found to be toxic. The response of pine to a decrease in soil fertility (due to its slow response) was determined as a result of a retrospective comprehensive ecological and physiological analysis of tabular phytomass data compiled by V.A. Usol’tsev (2002) for tree stands growing in the European and Asian parts of Russia in the age range from 10–20 to 150–300 years. The natural decrease in soil fertility of pine stands with the age from 25 to 100 years in all the regions caused a decrease in nitrogen uptake by 18.5–84.5 times, and net productivity of photosynthesis by 3.4–18.0 times. The correlation between plant age, nitrogen uptake, and net productivity of photosynthesis ranged from –0.714 to –0.870 and –0.894 to –0.991, respectively. The decrease in the activity of photosynthetic apparatus and root system adversely affected the biological productivity, which fell from 2.8 to 4.0 times depending on the region. The relationship between biological productivity and age was high negative (correlation coefficient ranged from –0.572 to –0.783). The relationship between mineral productivity with biological productivity and net productivity of photosynthesis in all cases was high positive from 0.907 to 0.994 and from 0.757 to 0.932, respectively. Starting from the age of 25, the plants adapted to a decrease in soil fertility by increasing the ratio of root to photosynthetic potential, which grew from 4.8 to 12.5 times during ontogenesis depending on the region. This nonspecific reaction is confirmed by the high positive correlation (from 0.947 to 0.997) of the ratio of root to photosynthetic potential with the tree age.For citation: Lebedev V.M., Lebedev E.V. Ecological and Physiological Features of the Scots Pine Reaction to the Soil Fertility Level as an Indicator of Adaptation to Environmental Conditions. Lesnoy Zhurnal [Russian Forestry Journal], 2019, no. 6, pp. 92–103. DOI: 10.17238/ issn0536-1036.2019.6.92

Seminal roots of wild and cultivated barley differentially respond to osmotic stress in gene expression, suberization, and hydraulic conductivity.

Wild barley, Hordeum vulgare spp. spontaneum, has a wider genetic diversity than its cultivated progeny, Hordeum vulgare spp. vulgare. Osmotic stress leads to a series of different responses in wild barley seminal roots, ranging from no changes in suberization to enhanced endodermal suberization of certain zones and the formation of a suberized exodermis, which was not observed in the modern cultivars studied so far. Further, as a response to osmotic stress, the hydraulic conductivity of roots was not affected in wild barley, but it was 2.5-fold reduced in cultivated barley. In both subspecies, osmotic adjustment by increasing proline concentration and decreasing osmotic potential in roots was observed. RNA-sequencing indicated that the regulation of suberin biosynthesis and water transport via aquaporins were different between wild and cultivated barley. These results indicate that wild barley uses different strategies to cope with osmotic stress compared with cultivated barley. Thus, it seems that wild barley is better adapted to cope with osmotic stress by maintaining a significantly higher hydraulic conductivity of roots during water deficit.

Efficient and easy micropropagation of Morus nigra and the influence of natural light on acclimatization

Micropropagation, which employs various plant growth regulators (PGRs) in the culture medium for the induction of multiple shoots as well as adventitious roots, is a widely-used technique for the propagation of the genus Morus. The main objective of the present study was to evaluate the effect of PGR-free culture medium on the quantitative and qualitative characteristics of the micropropagation of Morus nigra under the growth room and greenhouse environmental conditions. Although a higher rate of multiplication (4.7-5.2 shoots/explant) was obtained from the treatments using Benzyladenine (BA) as the PGR, the PGR-free culture medium also exhibited comparable multiplication rate (4.1 shoots/explant) with a higher quality of shoots and without any symptoms of hyperhydricity. Furthermore, the use of PGR-free culture of M. nigra for in vitro propagation combined the steps of shoot multiplication and rooting phase using the same culture medium, further simplifying the process. In this study, the micro-shoots were also assessed for their in-vitro rooting and acclimatization potential. The incubation of an in-vitro culture of nodal explants in a controlled growth room for 28 days exhibited optimum response with about 90% rooting and 100% plantlet survival during the acclimatization phase. These results were better than those incubated under greenhouse conditions.

Method for initially selecting Al-tolerant rice varieties based on the charge characteristics of their roots

To explore the relationship between charge characteristics of rice roots and aluminum (Al) tolerance of rice, roots of 47 different rice genotypes were obtained by hydroponic experiment. The zeta potentials of roots were determined by streaming potential method, and the Al tolerance and the functional groups of rice were measured by relative root elongation and infrared spectroscopy (ATR-FTIR), respectively. The exchangeable, complexed and precipitated Al(III) sorbed on the root surface of rice was extracted with 1 mol L−1 KNO3, 0.05 mol L−1 EDTA-2Na and 0.01 mol L−1 HCl, respectively. There was a significant correlation between the zeta potentials and the relative elongation of rice roots, indicating that the zeta potentials of rice roots could be used to characterize rice tolerance to Al toxicity. Twelve Al-tolerant rice varieties, 25 medium Al-tolerant rice varieties, and 10 Al-sensitive rice varieties were obtained. The Al-tolerant rice varieties sorbed less complexed Al(III) and total Al(III) because there was lower negative charge on their roots compared to less tolerant genotypes. A correlation analysis showed that there were significant negative correlations between the zeta potential, relative root elongation, and the total Al(III) sorption capacity of the roots, which further confirmed the reliability of using the root zeta potential to characterize rice tolerance to Al toxicity. The results of this paper provide a new method for screening Al-tolerant rice varieties.

Impact of saline water irrigation plus potassium sulphate application on growth and yield potential of pepper plants

The aim of this research was to investigate the impact of different saline water irrigation levels plus potassium sulphate (K2SO4) application on growth and yield potential of pepper plants. The treatments consisted of three saline water irrigation levels (2.5, 4 and 6 dS m-1) and tab water as control. Each treatment was supplemented with different levels of K2SO4 at (zero, 2 and 4 gm K2SO4 per plant), except for the control. Plant observations were collected to evaluate plant length, fruit number per plant, fruit yield per plant, stem water potential, plant transpiration, photosynthetic rate and dry matter of shoots and roots. Results of this study indicated that K2SO4 application played a positive impact on alleviating salinity stress and improving plant growth parameters mainly under saline water irrigation levels of 2.5 and 4 dS m-1 plus 2 gm K2SO4 compared to saline water irrigation treatments which were not supplemented with K2SO4.

Water regime and osmotic adjustment under warming conditions on wheat in the Yaqui Valley, Mexico.

An experiment was carried out to evaluate the effect of increased temperature on roots and leaf water and osmotic potential, osmotic adjustment (OA) and transpiration on Triticum durum L. (CIRNO C2008 variety) during growth (seedling growth), tillering and heading phenophases. Wheat was sown under field conditions at the Experimental Technology Transfer Center (CETT-910), as a representative wheat crop area from the Yaqui Valley, Sonora México. Thermal radiators were placed at 1.20 m from the crop canopy. Treatments included warmed plots (2 °C) and ambient canopy temperature with five replicates. Temperature treatment was controlled using a (proportional, integrative, derivative) feedback control system on plots covering a circular area of r = 1.5 m. Results indicated a significant decrease in the osmotic potential of roots and leaves for the warmed plots. Water potential, under warming treatment, also experienced a significant reduction and a potential gradient was observed in both, roots and leaves, while the phenophases were delayed. Such results demonstrate that, under warmer conditions, plants increase water absorption for cooling. Hence, transpiration experienced a significant increase under warming in all phenophases that was related to the low root and leaf water potential. CIRNO C2008 also experienced OA in all phenophases with glycine betaine as the osmolyte with major contribution.

Second-Harmonic Generation Investigated by Topless Potential Well With Inverse Square Root

A short-range topless potential energy with inverse square root is introduced to solve the energy spectrum equations and the bound state wave functions of the static Schr $\ddot {\textrm {o}}$ dinger equation by coordinate variation and combining the extraordinary coefficients of the confluent hypergeometric functions. Furthermore, the model of second-harmonic generation (SHG) with this special potential energy $V(z)$ will appear regular changes. In this letter, we explore the specific characteristics of the second-harmonic generation under the inverse square root potential through multiple factors such as energy intervals and matrix elements.

Differential suppression of the ipsi- and contralateral nociceptive reflexes in the neonatal rat spinal cord by agonists of µ-, δ- and κ-opioid receptors

Nociceptive discharges caused by the unilateral tissue damage are processed in the spinal cord by both ipsi- and contralateral neuronal circuits. The mechanisms of the neurotransmitter control of this bilateral excitation spread is poorly understood. Spinally administered opiates are known to suppress nociceptive transmission and nociceptive withdrawal reflexes. Here we investigated whether three major types of opioid receptors are involved in the bilateral control of the spinal nociceptive sensorimotor processing. Effects of the µ-, δ- and κ-opioid receptor agonists on the ipsi- and contralateral nociceptive reflexes were studied by recording slow ventral root potentials in an isolated spinal cord preparation of the new-born rat. Absolute levels of expression of the opioid genes were analyzed by the droplet digital PCR. Ipsi- and contralateral slow ventral root potentials were most strongly suppressed by the µ-opioid receptor agonist DAMGO, by 63% and 85%, followed by the κ-opioid receptor agonist U-50488H, by 44% and 73%, and δ-opioid receptor agonist leucine-enkephalin, by 27% and 49%, respectively. All these agonists suppressed stronger contra- than ipsilateral responses. Naloxone prevented effects of the agonists indicating that they act through opioid receptors, which, as we show, are expressed in the neonatal spinal cord at the levels similar to those in adults. Thus, opioid receptor agonists suppress the segmental nociceptive reflexes. Stronger contralateral effects suggest that the endogenous opioid system regulates sensorimotor processing in the spinal commissural pathways. These effects of opioids may be relevant for treatment of symmetric clinical pain symptoms caused by unilateral tissue injury.