Index Of Membrane Permeability Research Articles

Identification of stable heat tolerance QTLs using inter-specific recombinant inbred line population derived from GPF 2 and ILWC 292.

Heat stress during reproductive stages has been leading to significant yield losses in chickpea (Cicer arietinum L.). With an aim of identifying the genomic regions or QTLs responsible for heat tolerance, 187 F8 recombinant inbred lines (RILs) derived from the cross GPF 2 (heat tolerant) × ILWC 292 (heat sensitive) were evaluated under late-sown irrigated (January-May) and timely-sown irrigated environments (November-April) at Ludhiana and Faridkot in Punjab, India for 13 heat tolerance related traits. The pooled ANOVA for both locations for the traits namely days to germination (DG), days to flowering initiation (DFI), days to 50% flowering (DFF), days to 100% flowering (DHF), plant height (PH), pods per plant (NPP), biomass (BIO), grain yield (YLD), 100-seed weight (HSW), harvest index (HI), membrane permeability index (MPI), relative leaf water content (RLWC) and pollen viability (PV)) showed a highly significant difference in RILs. The phenotyping data coupled with the genetic map comprising of 1365 ddRAD-Seq based SNP markers were used for identifying the QTLs for heat tolerance. Composite interval mapping provided a total of 28 and 23 QTLs, respectively at Ludhiana and Faridkot locations. Of these, 13 consensus QTLs for DG, DFI, DFF, DHF, PH, YLD, and MPI have been identified at both locations. Four QTL clusters containing QTLs for multiple traits were identified on the same genomic region at both locations. Stable QTLs for days to flowering can be one of the major factors for providing heat tolerance as early flowering has an advantage of more seed setting due to a comparatively longer reproductive period. Identified QTLs can be used in genomics-assisted breeding to develop heat stress-tolerant high yielding chickpea cultivars.

Use of morpho-physiological and biochemical traits to identify sources of drought and heat tolerance in chickpea (

Productivity of chickpea (Cicer arietinum) under current climatic conditions is severely limited by water deficit and high temperatures, either alone or in combination. Breeding for improved tolerance, and increasing understanding of the physiological and biochemical mechanisms underlying tolerance, are imperative for achieving yield stabilisation. We evaluated 36 chickpea genotypes including 21 interspecific derivatives (from the cross C. arietinum ICCV96030 × C. pinnatifidum IC525200), their parents, 10 elite genotypes, and three checks (drought tolerant, heat tolerant, drought and heat susceptible) under three environments: timely sowing with irrigation, timely sowing with drought stress, and late sowing leading to heat stress. Four parameters were considered: seed yield, proline content, membrane permeability index, and relative leaf water content. Although the average seed yield plummeted under both stresses, the impact of high temperature was more pronounced. Mean leaf water content declined, whereas membrane permeability index and proline content increased, under both stresses. Leaf water content showed a significant positive correlation with seed yield under all environments, and thus can be employed as an early-stage screening strategy in breeding programs for developing stress tolerant genotypes. Based on estimated stress susceptibility indices for seed yield, derivative line GLW605 was identified as a promising donor for both drought and heat tolerance. Additionally, three derivative lines (GLW607, GLW649, GLW677) were found tolerant to drought, and one derivative line (GLW669) showed tolerance to heat alone. Yield levels of the identified lines were statistically on par with respective tolerant checks. Results suggest that tolerance to drought and heat was successfully introgressed from the wild species, C. pinnatifidum, into the cultivated background. The promising derivative lines can be employed for developing multi-stress tolerant cultivars.

Physiological and Biochemical Responses of Chickpea Accessions at Reproductive Stage Under Receding Moisture Conditions

The present study was conducted to assess the physiological and biochemical responses in the leaves of ten chickpea accessions trifurcated into moderately tolerant, intermittent and moderately sensitive on the basis of their yield losses via drought susceptibility index. Moderately sensitive accessions recorded higher decline in number of leaves and dehydrogenase activity and increased membrane permeability index (MPI) under receding moisture conditions. However, moderately tolerant genotypes, viz. GL 29078 and ICC 4958, maintained number of leaves and optimal dehydrogenase activity and lower MPI in leaves at reproductive stages by enhanced enzymatic activity of superoxide dismutase, catalase and ascorbate peroxidase that upregulated their antioxidative defense system at 75% moisture reduction levels. Furthermore, the tolerance capacity was maintained in moderately tolerant genotypes (IPCK-2009-165 and ICC 4958) due to increased proline level that acted as a positive loading variable component in principal component biplot analysis and lowered malondialdehyde content levels in leaves at receding moisture levels. Assessment of leaf tissue-specific response under lysimetric screening and its final correlation with yield adds to paramount importance and uniqueness to the current study.

Physiological response of ornamental tree species to induced salinity

An experiment was conducted to explore the possibility about saline irrigation water may be used to grow ornamental tree species in pots under sub tropical condition of Punjab for two years (2015-16). Five salinity treatments of NaCl (analytical reagent) as 0 mM, 30 mM, 40 mM, 50 mM and 60 mM were given to one year old seedlings planted in earthen pots (10”) containing soil : FYM (2:1). These concentrations were given till October. After October month, i.e. in first week of November the treatments of NaCl as 0 mM, 30 mM, 60 mM, 90 mM and 120 mM were given. The results indicated that the increased salinity concentration in Bauhinia purpurea and Milletia ovalifolia significantly reduced the total chlorophyll, carotenoid and relative water content, whereas increased the cell membrane injury during both years. In Acacia auriculiformis and Cassia fistula, total leaf chlorophyll and carotenoids were maintained or slightly increased during first year and after that decreased, whereas relative water content increased with increase in salinity concentrations in first year and after that decreased. Electrolyte leakage in Acacia auriculiformis and Cassia fistula were maintained or slightly decreased during first year and during second year increased. It has been concluded that depending on the physiological responses, viz. total chlorophyll content, carotenoid content, relative water content and membrane permeability index, maximum salt tolerance was observed in Acacia auriculiformis followed by Cassia fistula, Bauhinia purpurea and Milletia ovalifolia.

Proline Content and Membrane Permeability Index in Response to Water Stress in Recombinant Inbred Lines of Lentil

Proline Content and Membrane Permeability Index in Response to Water Stress in Recombinant Inbred Lines of Lentil Proline content and membrane permeability index are important stress related parameters. Field experiments were conducted to examine the effect of proline and membrane permeability index on 135 recombinant inbred lines (RILs) under irrigated and rainfed conditions and to analyze their relationship with yield and its component traits in lentil. Higher content (1.89 ± 0.046 mg g-1 FW) of proline was found under rainfed conditions in comparison to irrigated (1.22 ± 0.040 mg g-1 FW). The membrane permeability index of lentil lines increased significantly under rainfed conditions from 63.17 to 84.32 percent. The seed yield was significantly higher in irrigated (122.88 g/plot) than in rainfed conditions (69.99 g/ plot). RILs were categorized in five subsets based on percent yield reduction due to water stress in rainfed conditions. It was found that RIL-23,-78,-86,-90,-95,-104,-109 and-111 recorded minimum yield reduction (15-30%) had higher proline accumulation (65.58%) while, RIL-51 with greater yield reduction (75-90%) showed only 7.92 percent increase in proline content under rainfed conditions thereby suggesting the role of proline as an osmoprotectant under stress conditions in lentil...

Moisture stress induced changes in metabolites and cellular functions in chickpea (Cicer arietinum L.) genotypes

The present investigation was aimed to study influence of moisture stress in in vitro identified tolerant (GL28151, RSG963, PDG3) and sensitive (GL22044, GNG1861, PBG1) chickpea genotypes under field conditions. Moisture stress treatments included crop sown with one pre-sowing irrigation (WSVFP), irrigation withheld at flower initiation stage (WSF), irrigation withheld at pod initiation stage (WSP) and control (irrigated as and when required). Osmolytes (in seeds) viz. total soluble sugars, starch, proline, cellular functions; relative water content, membrane permeability index and lipid peroxidation (in leaves), antioxidant enzymes (at pod filling stage) viz. peroxidase, catalase, superoxide dismutase, glutathione reductase were estimated in chickpea seeds under control and stressed conditions. WSVFP was most severely affected by moisture stress followed by WSP and WSF and emphasized on pod intuition stage as critical stage attributable to hindered transport of assimilates towards formation of pods and development of seeds under stress imposed by lack of sufficient moisture. Highest accumulation of total soluble sugars (73.33), starch (73.12), proline (2.04) in mg/g fresh weight, least percentage reduction over control in relative water content (20.3), membrane permeability index (18.8) and minimal lipid peroxidation (31.3) accompanied by significantly enhanced activities of antioxidant enzymes under WSVFP rendered moisture stress tolerance in RSG963. The pronounced cellular damage, lesser alleviation in the content of osmolytes, antioxidant enzymes activity was observed in sensitive genotype GL22044 under stress treatments. High molecular weight protein bands were found either absent or of low intensity in sensitive genotypes (GL22044, GNG1861 and PBG1) under severe stress treatment (WSVFP).

Water deficit stress tolerance in chickpea is mediated by the contribution of integrative defence systems in different tissues of the plant.

Drought induces heavy yield losses in chickpea (Cicer arietinum L.). Besides understanding the physiological and biochemical parameters contributing to drought tolerance, we need to understand the importance of one tissue in combatting drought stress-induced oxidative stress and influencing the antioxidative defence system in other tissues. The study was conducted to examine the influence of drought stress conditions on the antioxidative defence system and physiology in different tissues such as roots, leaves, nodules, pod walls and seeds at various vegetative and reproductive growth stages in two chickpea cultivars differing in rooting behaviour: ICC4958 (deep rooted) and ILC3279 (shallow rooted). The traits contributing to drought tolerance in ICC4958 were increased root area, decreased leaf area index or increase in root area, decreased leaf area; ILC3279 displayed a decrease in root area and an increase in LAI. The adaptation of ICC4958 was also accompanied by biochemical adjustments, like increases in antioxidative enzymes (superoxide dismutase, peroxidase, ascorbate peroxidase, glutathione reductase and catalase) and nonenzymatic antioxidants (ascorbic acid, proline and stress-induced proteins). However, increases in antioxidant enzymes, nonenzymatic antioxidants and proteins in ILC3279 were lower than in ICC4958. The lower malondialdehyde content and membrane permeability index in ICC4958 might be responsible for reduced damage under drought stress. Increased H2O2 content in ICC4958 was related to enhanced antioxidative defence, emphasising its role as a signalling molecule under stress. This is the first study conducted on drought stress-induced enzymatic and nonenzymatic antioxidative defence systems in underground, aboveground vegetative and reproductive tissues in chickpea cultivars differing in rooting behaviour.

NH3 Permeability versus CO2 Permeability: Insights from Mathematical Modeling

Exposing a cell to a solution containing NH3/NH4+ leads to a rapid NH3 influx, which causes a rise in intracellular pH (pHi) and a transient decrease in surface pH (pHS). Conversely, exposing a cell to a solution containing CO2/HCO3− leads to a rapid CO2 influx, which causes a fall in pHi and a transient increase in pHS.In our laboratory we use the maximal change in the height of the pHS transient (ΔpHS) as a semiquantitative index of membrane permeability to NH3 (PM,NH3) or to CO2 (PM,CO2). As a first step in extracting absolute membrane permeability from pHS measurements, in 2012 we developed a reaction‐diffusion mathematical model of CO2 influx to investigate the dependence of ΔpHS predicted by the model on PM,CO2 values (Somersalo et al, J Theor Biol, 2012). To account for physiological data on gas channels, the model predicts that,contrary to widespread assumptions, the membrane must offer considerable resistance to the movement of CO2.Here, we investigate the dependence of ΔpHS versus PM,NH3 with a reaction‐diffusion mathematical model of NH3 influx into a spherical cell. The model is an extension of the model of Somersalo et al, in which now we include the NH3/NH4+ buffer equilibrium and passive transmembrane flux of NH3. After having checked that the model correctly predicts the transient changes in pHi and pHS that one would expect as NH3 enters a cell, we performed simulations in which we systematically decreased PM,NH3 from that corresponding to a thin film of water. By comparing the dependence of ΔpHS versus a range of PM,NH3 (present study) with the dependence of ΔpHS versus PM,CO2 (Somersalo et al), we conclude that, contrary to the Overton's prediction (which considers only solubility in the membrane), the background PM,NH3 (in absence of gas channels) is far higher than the background PM,CO2.

Fluorescein chemiluminescence method for estimation of membrane permeability of liposomes

Unilamellar liposomes have a compartment enclosed by a single lipid bilayer. Encapsulation of compounds, such as drugs, genes, and enzymes, into liposomes has been applied successfully to drug delivery systems and cosmetics [1,2]. For these applications of liposomes, control, and characterization of release and leakage of compounds are very important. Release and leakage are attributable to the membrane permeability, and in some cases to instability, of the liposomes. The assay of membrane permeability is generally performed by monitoring the release of fluorescein derivatives, such as 5(6)-carboxyfluorescein and calcein (bis[N,N 0-di(carboxymethyl)-aminoethyl] fluorescein), encapsulated in liposomes [3,4]. In these assays, the dyes are encapsulated in liposomes at concentrations greater than 50–100 mM, where more than 95% of fluorescence of the dyes is self-quenched. Release of the dyes inside liposomes leads to an increase in fluorescence intensity due to the reduction of self-quenching. The percentage of released dye over a certain period is used as an index of membrane permeability. The dyes exhibit low permeability to bilayer because the dyes have multiple negative charges. Release of the dyes, therefore, requires several hours or days. It is generally difficult to use fluorescein for dye-release assay because encapsulated fluorescein leaks rapidly from the inner phase of liposomes during separation of the free dye. On the other hand, we previously reported a chemiluminescence (CL) reaction inside liposomes encapsulating horseradish peroxidase

ウメ果実の収穫熟度による低温障害感受性の差異とリン脂質成分及び膜透過性との関連について

In our previous paper, it was reported that mume fruits became chilling-insensitive when they were harvested at a late period, and that the surface color of the stone may be a useful criterion of harvest time. This paper deals with the changes in stone color, K+ leakage rate, and phospholipid composition with reference to fruit maturity and chilling sensitivity.1. ‘Ohshuku’ mume fruits were harvested at weekly intervals from May 16 to June 13 and investigated for the relation between surface color of the stone and fruit maturity. The stone was white in fruits harvested before May 30, and the embryos were not yet matured. Stone color changed to light brown in fruits harvested on June 6 and the embryos were mature.2. HCl-soluble pectin content decreased rapidly after June 6 and water-soluble pectin content increased concomitantly. Citric acid content increased and malic acid content decreased during maturation; especially, a marked decrease of malic acid content was found after June 6.3. The number of days from harvest to the beginning of rapid increase of CO2 and C2H4 production, and peel yellowing, decreased during maturation. A marked decrease was found between May 23 and June 6.4. As an index of membrane permeability, the rate of K+ leakage was measured at 3, 6, 8°C on the harvest day, and its relation to chilling sensitivity was investigated. The rate of K+ leakage was low in fruits harvested from May 23 to June 6; these fruits showed high chilling sensitivity.5. As an index of membrane flexibility, the phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio was investigated in relation to harvest maturity. Theratio was very low in fruits harvested from May 23 to June 6, which showed high chilling sensitivity. Fruits harvested on June 13 showed a high ratio and low chilling sensitivity.From these results it was concluded that the time of stone-color change from white to light brown or brown coincides with a physiological turning point of fruits, and that mume fruits acquire chilling resistance after that.

Continuous Arteriovenous Haemofiltration and Haemodiafiltration in Acute Renal Failure

Continuous arteriovenous haemofiltration (CAVH) was employed in ten patients with acute renal failure using an AN-69 plate filter. Special measures were taken to improve the efficiency of the technique, including the use of short, large-bore catheters for vascular access, predilution infusion of the substitution fluid, and moderate vacuum suction to the ultrafiltrate compartment. In five patients continuous arteriovenous haemodiafiltration was performed by the addition of slow dialysis at a dialysate flow of 1 litre per hour. This technically simple manoeuvre enhanced solute clearances up to 20 ml/min and obviated the need for standard intermittent dialysis sessions in all cases. Repeated measurements of transmembrane pressure and ultrafiltration rate permitted calculation of the in vivo membrane permeability index, which showed a reproducible decline with time. With relatively low heparin requirements an adequate filter performance could be maintained for over 48 h. The encouraging clinical results indicate that CAVHD, in spite of the invasive nature of this technique, may be considered a first-choice treatment for patients with acute renal failure in the intensive care unit.

低温ショックによるウメ果実の低温障害抑制効果と膜透過性及び膜脂質構成脂肪酸の変化との関係

It has been reported that chilling injury in mume (Japanese apricot) fruits usually occurs much sooner at 5-8°C (moderate low temperature) than at 0-1°C, and that a cold-shock treatment by hydrocooling in ice water immediately after harvest is effective in retarding the development of the chilling injury. This paper deals with the mechanism of the cold-shock treatment.1. As an index of membrane permeability, the rate of K+ion leakage from tissue slices into water was measured at various temperatures ranging from 1°C to 20°C. While the leakage rate of chilling-insensitive potato tuber decreased as the temperature was lowered, that of chilling-sensitive cucumber fruits showed no decrease at low temperatures, remaining at an almost constant level below 10°C. However leakage rate of mume fruits, showed an unusual increase at moderate low temperatures (5-8°C). Using 4 cultivars of mume fruits, ‘Yosei’‘Nanko’‘Gyokuei’and ‘Gojiro’it was found that the temperature at which the unusual increase of K+ion leakage occurred on harvest day was almost the same as that at which severe chilling injury occurred during storage.2. When‘Oshuku’mume fruits, a very chilling-sensitive cultivar, were given a cold-shock in ice water for 2 hours and then stored at 6°C, chilling injury was retarded. Except for a temporary rise soon after the treatment, the rate of K+ion leakage remained at a constant low level. However, in untreated fruits, the rate of K+ion leakage increaesed markedly during storage at 6°C.Fatty acid composition of membrane lipids was analyzed, and C16:0 was found to be most abundant, followed by C18:2, C18:3, C18:1, C16:1, C14:0, C18:0 in that order. The ratio of unsaturated fatty acids to total fatty acids was 52%, a relatively low value compared with other commodities, suggesting a lower tolerance to chilling temperature. Cold-shock treatment increased the above ratio.Total phenol content gradually increased both in the untreated and treated fruits during 6°C storage, the values being slightly lower in the treated fruits. Activities of polyphenol oxidase and peroxidase increased during 6°C storage. No relation tocold-shock effect was found. NADH-cytochrome C reductase activity, an index of activity of the enzymatic system involved in unsaturation of fatty acids, increased rapidly during the cold-shock treatment and remained at a higher level than in untreated fruits throughout the 6°C storage period.3. From these results, it was concluded that the effect of the cold-shock treatment was to accelerate the desaturation of fatty acids in membrane lipids.

Increased muscle permeability to aldolase produced by depolarization and by metabolic inhibitors.

Aldolase leak from rat peroneus longus muscle is assumed to occur by diffusion and its magnitude is taken to be an index of membrane permeability. Aldolase efflux is increased by high external K concentration, presumably owing to membrane depolarization. Mg lack may be slightly effective. Metabolic inhibitors, iodoacetate, dinitrophenol or cyanide, markedly increase aldolase efflux. These observations, with earlier ones on the effects of anoxia and of glucose lack, suggest that muscle membrane is labile, its permeability linked to cellular metabolism. A dynamic model of muscle membrane is proposed in which sites through which diffusion can occur ripple over the cell surface.

Diffusion of aldolase from rat skeletal muscle; an index of membrane permeability.

It was shown previously that a protein, aldolase, flows from excised rat diaphragm incubated in a variety of media. Because muscle fibers are cut in this preparation there was some question about the absolute values of permeability of the diaphragm. These experiments have been repeated using a small muscle with two tendinous insertions, the peroneus longus. In addition to confirming increased permeability during anoxia, glucose lack, altered metabolism produced by transferring muscle to fresh media, and probable membrane depolarization by potassium, it was shown that there is no greater permeability in phosphate buffer than in bicarbonate buffer and that the aldolase in the effluent (as percentage of total muscle aldolase) decreases as the weight of muscle increases. The latter relation is predicted approximately from surface/volume ratio of cylindrical fibers which decreases as volume increases.