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Exogenous application of salicylic acid (SA) to plant tissues has been shown to confer tolerance against various abiotic stresses. Recently, SA application through sub-irrigation was shown to improve plant freezing tolerance (FT). For SA treatment to be employable as an effective intervention strategy for frost protection under field conditions, it is important to study its effect on FT when applied as a foliar spray to whole plants. It is also important to determine for how long the FT-improvement by SA lasts. Present study was conducted to compare SA-induced FT of spinach (Spinacia oleracea L. 'Reflect') seedlings following SA-application by foliar spray vs. sub-irrigation. Durability of FT-promotive effect of SA was evaluated using three freeze-tests over a 4-d period, i.e., at 10-d, 12-d, and 14-d after the SA application. Freezing stress was applied using a temperature-controlled freeze-thaw protocol, and FT was assessed by visual observations (leaf flaccidness vs. turgidity) as well as ion-leakage assay. Data indicated that both foliar spray and sub-irrigation methods improved FT of the seedlings against a relatively moderate (-5.5 °C) as well as severe stress (-6.5 °C). Moreover, improved FT against moderate stress was sustained over a 4-d period, whereas such benefit waned somewhat against the severe stress. SA-treated leaves' growth performance was similar to the non-treated control based on dry weight, fresh weight, leaf area, and dry weight/leaf area parameters. Our results suggest that SA application as a foliar spray can potentially be used to protect field-grown transplants against episodic frosts.

Premise Thermonastic leaf movements in evergreen Rhododendron species have been used to study plant strategies for winter photoprotection. To add to the current fundamental understanding of this behavior, we addressed the following questions: (1) Is the cold-acclimated (CA) state necessary for thermonasty, and do cold-induced leaf movements also occur in non-acclimated (NA) plants? (2) Which of the two movements, leaf rolling versus curling, is more responsive to freezing, if any, in a non-thermonastic species? (3) What is the temporal relationship between extracellular freezing and thermonasty? (4) What genetic inferences can be drawn from leaf movement in an F1 hybrid relative to its parents? Methods A temperature-controlled, gradual cooling regime was used to quantify freeze-induced leaf movements. Infrared thermography was used to confirm extracellular ice-formation in leaves. Results Both NA and CA plants of thermonastic species exhibited thermonasty, but leaf rolling/curling increased significantly in CA plants. In the cold-acclimated condition, a non-thermonastic species showed almost no rolling during freezing, while the thermonastic species and F1 hybrid did, the latter exhibiting a response intermediate to the parents. Freezing-induced leaf curling in the non-thermonastic species and the F1 hybrid was equivalent and significantly less than the degree of curling in the thermonastic species. Conclusions Milder thermonasty in NA than CA leaves could be associated with differential anisotropy in the rolling forces and/or response of aquaporins to freezing. Leaf movements in the hybrid suggest that leaf rolling and curling are additive and dominant genetic traits, respectively. Infrared thermography confirms that ice formation in tissues precedes cold-induced thermonasty in R. catawbiense.

Researchers have used nanomaterials, rice husk ash, coal fly ash, and conducting polymer Polypyrrole used for the adsorption purpose for Hg, Zn, Mn, Cu and, Cr heavy metal. Here the conducting polymer Polyaniline and rice husk are used for the adsorption of chromium from potassium dichromate (K2Cr2O7) solution. The FTIR, SEM and UV Spectroscopy study were completed for the conducting polymer Polyaniline. A Sieve shaker was used for the determination of the size of rice husk particles in the adsorption process of chromium. It was observed that the more effective adsorbent conducting polymer Polyaniline in lesser quantity and effectively decreasing the COD (Chemical Oxygen demand) from potassium dichromate solution.

Nanoparticles are used by the researchers for the purifications of wastewater or groundwater. The different modified nanomaterials as adsorbents are used by the researchers mainly removing the arsenic impurities. The modified nanoparticles having improved physical properties, chemical stability, easy regeneration, environment stable, adsorption coefficient high, less space requirements, more lifetime, low cost, and high capacity to adsorbate the pollutants. This study reviewed the current and past nanomaterials used for the arsenic adsorbent purpose by using different techniques.

In situ polymerization techniques had been used for the development of nanoTiO2 based conducting polymer Polyaniline nanocomposite materials. The film was developed with aqueous soluble high molecular weight polyvinyl alcohol (PVA) and nano TiO2 for increasing thermal stability and mechanical properties of nanocomposite material. The different weight compositions of nanocomposite (30%-40%) had been used for the fabrication of film with PVA. The film was characterized by dc conductivity between 20 V and 500 V and it was observed that dc conductivity of the film can be regulated between these voltages.

Cold acclimation (CA) is a well-known strategy employed by plants to enhance freezing tolerance (FT) in winter. Global warming could disturb CA and increase the potential for winter freeze-injury. Thus, developing robust FT through complete CA is essential. To explore the molecular mechanisms of CA in woody perennials, we compared field and artificial CAs. Transcriptomic data showed that photosynthesis/photoprotection and fatty acid metabolism pathways were specifically enriched in field CA; carbohydrate metabolism, secondary metabolism and circadian rhythm pathways were commonly enriched in both field and artificial CAs. When compared with plants in vegetative growth in the chamber, we found that the light signals with warm air temperatures in the fall might induce the accumulation of leaf abscisic acid (ABA) and jasmonic acid (JA) concentrations, and activate Ca2+ , ABA and JA signaling transductions in plants. With the gradual cooling occurrence in winter, more accumulation of anthocyanin, chlorophyll degradation, closure/degradation of photosystem II reaction centers, and substantial accumulation of glucose and fructose contributed to obtaining robust FT during field CA. Moreover, we observed that in Rhododendron 'Elsie Lee', ABA and JA decreased in winter, which may be due to the strong requirement of zeaxanthin for rapid thermal dissipation and unsaturated fatty acids for membrane fluidity. Taken together, our results indicate that artificial CA has limitations to understand the field CA and field light signals (like short photoperiod, light intensity and/or light quality) before the low temperature in fall might be essential for complete CA.

Thermonastic leaf movements in evergreen Rhododendron species have been used to study plant strategies for winter photoprotection. To add to the current fundamental understanding of this behavior, we addressed the following questions: (1) Is the cold-acclimated (CA) state necessary for thermonasty, and do cold-induced leaf movements also occur in non-acclimated (NA) plants? (2) Which of the two movements, leaf rolling versus curling, is more responsive to freezing, if any, in a non-thermonastic species? (3) What is the temporal relationship between extracellular freezing and thermonasty? (4) What genetic inferences can be drawn from leaf movement in an FA temperature-controlled, gradual cooling regime was used to quantify freeze-induced leaf movements. Infrared thermography was used to confirm extracellular ice-formation in leaves.Both NA and CA plants of thermonastic species exhibited thermonasty, but leaf rolling/curling increased significantly in CA plants. In the cold-acclimated condition, a non-thermonastic species showed almost no rolling during freezing, while the thermonastic species and FMilder thermonasty in NA than CA leaves could be associated with differential anisotropy in the rolling forces and/or response of aquaporins to freezing. Leaf movements in the hybrid suggest that leaf rolling and curling are additive and dominant genetic traits, respectively. Infrared thermography confirms that ice formation in tissues precedes cold-induced thermonasty in R. catawbiense.

The nano composite film was prepared with 50 nm nano TiO2–polyaniline (PANI) and polyvinyl alcohol (PVA). The conducting polymer PANI/50 nm (TiO2) composite was synthesized by employing in situ polymerization techniques. This nanocomposite material was used with polyvinyl alcohol for forming the nano composite film in different compositions. The composite films were characterized for morphology and DC conductivity. SEM images also indicated the fibrous structure of the composite film. Dielectric behavior and ac conductivity of the composite films were investigated in the frequency range 20 kHz to 1 MHz. The nanocomposite film had shown high dielectric constant. It was observed that both dielectric properties decreased with increase in frequency.

Plant tissues subjected to short or prolonged freezing to a fixed sub-freezing temperature are expected to undergo similar freeze-desiccation but the former causes substantially less injury than the latter. To gain metabolic insight into this differential response, metabolome changes in spinach (Spinacia oleracea L.) leaves were determined following short-term (0.5 and 3.0 h) vs. prolonged freezing (5.5 and 10.5 h) at -4.5°C resulting in reversible or irreversible injury, respectively. LD50 , the freezing duration causing 50% injury, was estimated to be ∼3.1 h and defined as the threshold beyond which tissues were irreversibly injured. From 39 identified metabolites, 19 were selected and clustered into 3 groups: (1) signaling-related (salicylic acid, aliphatic and aromatic amino acids), (2) injury-related (GABA, lactic acid, maltose, fatty acids, policosanols, TCA intermediates) and (3) recovery-related (ascorbic acid, α-tocopherol). Initial accumulation of salicylic acid during short-term freezing followed by a decline may be involved in triggering tolerance mechanisms in moderately injured tissues, while its resurgence during prolonged freezing may signal programmed cell death. GABA accumulated with increasing freezing duration, possibly to serve as a 'pH-stat' against cytoplasmic acidification resulting from lactic acid accumulation. Mitochondria seem to be more sensitive to prolonged freezing than chloroplasts since TCA intermediates decreased after LD50 while salicylic acid and maltose, produced in chloroplasts, accumulate even at 10.5-h freezing. Fatty acids and policosanols accumulation with increasing freezing duration indicates greater injury to membrane lipids and epicuticular waxes. Ascorbic acid and α-tocopherol accumulated after short-term freezing, supposedly facilitating recovery while their levels decreased in irreversibly injured tissues.

For winter survival, evergreens not only need cold acclimation (CA), but also photoprotection. This study was conducted to examine how two elevational ecotypes of Rhododendron catawbiense respond to cold and light stresses in a common garden. Seasonal changes in leaf freezing tolerance (LFT), photosystem II efficiency, photosynthesis, carotenoids (xanthophyll cycle pigments, lutein, beta-carotene, neoxanthin) were investigated from summer to winter. Parallel changes in the expression of violaxanthin de-epoxidase (VDE) gene were examined to explore its association with violaxanthin de-epoxidation. High elevation (HE) ecotype attained overall greater LFT while low elevation (LE) ecotype was more responsive to short-days for the first stage of CA. In summer, both ecotypes predominantly employed reversible xanthophyll cycle (RXC) to dissipate excess light energy, but LE used it more robustly. In autumn, only HE exhibited slight damage to the reaction centers (RCs), i.e. photosystem II degradation (PSD). In winter, both ecotypes suspended photosynthesis, were photoinhibited, and employed primarily sustained de-epoxidation (SD) for photoprotection; but LE still used RXC more effectively than HE. Overall, LE employed xanthophyll cycle more robustly in summer or winter. Results suggest that microclimates of R. catawbiense ecotypes inform their differential physiological response to cold and light stresses. VDE expression data indicate violaxanthin de-epoxidation in R. catawbiense may not be solely transcriptionally regulated.

Many researchers have used coal fly ash; rice husk ash, nano material and conducting polymer- as adsorbents to remove water pollutants including Cr, Pb, Hg, Zn, Mn and Cu, heavy metal. The main objective in this study to identify the nano materials used for heavy metal adsorption process effectively. The different parameters, pH, contact time etc. which affect the adsorption process. By reviewing this paper to find out the scope of conducting polymer based nanocomposite for heavy metal removal in aqueous system.

Freezing tolerance and metabolome changes were investigated for spinach (Spinacia oleracea L. ‘Reflect’) seedlings treated with 0.5 mM salicylic acid by sub-fertigation. Experiments included seedlings treated with salicylic acid at both the ambient (non-acclimation; NA) and cold acclimation (CA) temperatures, i.e. NASA and CASA. Except for slight reduction in the leaf size, salicylic acid-fed plants exhibited, in general, similar growth performance as non-treated controls based on the dry weight/fresh weight ratio, percent water content, and dry weight/leaf area. Temperature-controlled in situ freeze-thaw of seedlings revealed NASA plants were more freeze-tolerant (visual estimates and ion-leakage test) and had higher salicylic acid content than NA control. Metabolite profiling revealed NASA had higher trehalose, ascorbic acid, γ-tocopherol, proline, and leucine, whereas lower mannose and aconitic acid than NA tissues. Excised leaf freeze-thaw tests revealed CASA leaves to be the most freeze-tolerant of the four conditions followed, respectively, by CA, NASA, and NA. Principal component analysis distinctly separated metabolic phenotypes for NA, NASA, CA, and CASA, indicating salicylic acid differentially affected metabolism at warm vs. cold. CASA leaves had higher compatible solutes (osmolytes), antioxidants, and salicylic acid than CA control. Our data suggests that altered accumulation of trehalose, ascorbic acid, and aconitic acid was a salicylic acid-specific response. Additionally, 7 metabolites (5-oxoproline, fructose, glucose, maltose, proline, sucrose, and tartaric acid) were quantitatively associated with the freezing tolerance levels across four conditions.

A conducting nanocomposite film of 60 nm nano-SnO2-polyaniline (PANI) and polyvinyl alcohol (PVA) has been synthesized and analyzed in terms of AC conductivity and dielectric behavior. The conducting polymer nanocomposite of PANI/60 nm (SnO2) and polyvinyl alcohol (PVA) has been prepared via in situ polymerization technique. The morphology of the nanocomposite film has been studied by SEM. The film has been characterized in terms of DC conductivity. The dielectric behavior and AC conductivity of the nanocomposite film have been investigated in the frequency range of 2 Hz to 90 KHz. The film has high dielectric constant which may be correlated with polarization. It has been observed that both dielectric loss and dielectric constant decrease with an increase in frequency.

The UML was designed as a graphical notation for use with object-oriented systems and applications. Because of its popularity, now it is emerging in the field of embedded systems design as a modeling language. The UML notation is useful in capturing the requirements, documenting the structure, decomposing into objects and defining relationships between objects. It is a notational language that is very useful in modelling the real-time embedded systems. This paper presents the requirements and analysis modelling of a real-time embedded system related to a control system application for platform stabilization using COMET method of design with UML notation. These applications involve designing of electro mechanical systems that are controlled by multi-processors. Keywords: UML, embedded systems, platform stabilization

Freeze-thaw stress is one of the major environmental constraints that limit plant growth and reduces productivity and quality. Plants exhibit a variety of cellular dysfunction following freeze-thaw stress, including accumulation of reactive oxygen species (ROS). This means that enhancement of antioxidant capacity by exogenous application of antioxidants could potentially be one of major strategies for improving freezing tolerance (FT) of plants. Exogenous application of ascorbic acid (AsA), as an antioxidant, has been shown to improve plant tolerance against abiotic stresses but its effect on FT has not been investigated. We evaluated the effect of AsA-feeding on FT of spinach (Spinacia oleraceaL.) at whole-plant and excised leaf level, and conducted metabolite profiling of leaves before and after AsA-treatment to explore metabolic explanation for change in FT. AsA-application did not impede leaf-growth; instead slightly promoted it. Temperature-controlled freeze-thaw tests revealed AsA-fed plants were more freezing tolerant as indicated by: 1) less visual damage/mortality; 2) lower ion-leakage; and 3) less oxidative-injury, lower abundance of free radicals (O2•−and H2O2). Comparative leaf metabolic profiling revealed clear separation of metabolic phenotypes for controlvs. AsA-fed leaves. Specifically, AsA-fed leaves had greater abundance of antioxidants (AsA, glutathione, alpha-& gamma-tocopherol) and compatible solutes (proline, galactinol, myo-inositol). AsA-fed leaves also had higher activity of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, catalase). These changes, together, may improve FT via alleviating freeze-induced oxidative stress as well as protecting membranes from freeze-desiccation. Additionally, improved FT by AsA-feeding may potentially include enhanced cell wall/lignin augmentation and bolstered secondary metabolism as indicated by diminished level of phenylalanine and increased abundance of branched amino acids, respectively.

Understanding cellular mechanism(s) of freeze-thaw injury (FTI) is key to the efforts for improving plant freeze-tolerance by cultural methods or molecular/genetic approaches. However, not much work has been done in the last 25+ years to advance our understanding of the nature and cellular loci of FTI. Currently, two FTI lesions are predominantly implicated: 1) structural and functional perturbations in plasma membrane; 2) ROS-induced oxidative damage. While both have stood the test of time, many questions remain unresolved and other potentially significant lesions need to be investigated. Additionally, molecular mechanism of post-thaw recovery (PTR), a critical component of frost-survival, has not been well investigated. Mechanistic understanding of repair after reversible injury could expand the options for strategies to improve frost-hardiness. In this review, without claiming to be exhaustive, I have attempted to synthesize major discoveries from last several decades on the mechanisms of FTI and the relatively little research conducted thus far on PTR mechanisms. It is followed by proposing of hypotheses for mechanism(s) for irreversible FTI or PTR involving cytosolic calcium and ROS signaling. Perspective is presented on some unresolved questions and research on new ideas to fill the knowledge gaps and advance the field.

Supplemental calcium (Ca2+) fertilization has been reported to enhance plant tolerance against various abiotic stresses, however, its effect on freezing tolerance has not been well studied. We investigated the effect of Ca2+ supplementation on freezing tolerance of spinach (Spinacia oleracea L.) at whole-plant as well as excised-leaf level. Seedlings supplemented with 20 and 25 mM Ca2+ through sub-irrigation efficiently assimilated Ca2+, evident by higher leaf-Ca2+content. Supplemental Ca2+ did not impede leaf-growth (leaf-area) but slightly increased dry weight/fresh weight ratio compared to the control. Supplemental Ca2+ significantly improved freezing tolerance as evident by reducing K+/Mg2+/total ion-leakage (i.e. indicative of less membrane damage), alleviating oxidative stress (less accumulation of O2 and H2O2), and enhancing PSII potential quantum yield /energy trapping efficiency (Fv/Fm) following a relatively moderate or severe freeze-thaw stress, i.e. −5.5 and −6.5 ˚C. Improved freezing tolerance by Ca2+ supplementation was paralleled by enhanced activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). Our data further suggests that, besides a bolstered antioxidant status, improved freezing tolerance of Ca2+-fed seedlings may also be associated with reduced loss of Ca2+ from plasma membrane (due to lower abundance of leaked K+ in extracellular spaces) as well as due to increased mechanical strength of cell wall as evident by cell wall augmentation.

The physical properties of Ag doped Se based ternary glassy alloys have been examined theoretically. (Se70Te30)100-xAgx (0.0 ≤ x ≤ 8.0) chalcogenide alloys have been prepared by quenching method. The results show that the system is in floppy mode having constant average coordination number 2. The estimated density shows an increase with the Ag content. The mean bond energy and glass transition temperature vary in a similar fashion with an increment in Ag atomic % in the Se-Te system. The value of cohesive energy (1.91eV/mol to 1.97 eV/mol) and average bond strength (24.19 kcal/mol to 25 kcal/mol) has shown increasing trend in the system. From the results of the investigated samples, the covalency parameter > 90%. So, it can be assumed that compositions are stable glass formers and may be used in the infrared system.

Seasonal deacclimation was investigated during Jan. to Mar. 2014 in leaves of 10 azalea cultivars (Rhododendron section Tsutsusi) under natural conditions in eastern China. Based on the midwinter leaf freezing tolerance (LFT), these cultivars were grouped as “more-hardy” vs. “less-hardy.” Eight of the 10 cultivars first showed deacclimation when daily mean temperature over 2-week period preceding the LFT measurement was ≈9.5 °C. Deacclimation for other two cultivars was somewhat delayed and might have involved deacclimation–reacclimation cycling before eventual deacclimation. Our data indicate that the “more-hardy” group deacclimated slower than the “less-hardy” ones over the first half of the deacclimation period. This trend reversed during the second half of the deacclimation period. Accordingly, “more-hardy” and “less-hardy” cultivars depicted a “curvilinear” and “reverse curvilinear/linear” deacclimation kinetics. “More-hardy” cultivars generally had higher total soluble sugars (TSS) than “less-hardy” ones at acclimated state. TSS declined during deacclimation in all cultivars, and the loss was positively correlated with the loss in LFT. Leaf starch content generally followed opposite trend to that of TSS, i.e., it was at lowest during acclimated state and increased during deacclimation.

Proline (Pro), one of amino acids, not only acts as an osmoprotectant but also is involved in plant developmental processes. We previously revealed that Pro levels increased in peach (Prunus persica) shoots during dehardening in response to warmer temperatures during spring or in controlled laboratory conditions. Our subsequent work suggested that such Pro accumulation is associated with the resumption of growth in eco-dormant shoots and mediated via the ornithine pathway in peach. The present study was conducted to explore whether the aforementioned Pro accumulation response also occurs in other species of the Rosaceae family. Our data indicate that the Pro content of peach and plum (P. salicina) shoots increased during the spring regrowth and were highly similar between these two related species. Whereas the ornithine-δ-aminotransferase (OAT) gene expression dynamics in peach were correlated with Pro accumulation pattern and with pyrroline-5-carboxylate reductase (P5CR) gene expression, OAT expression was not correlated with the Pro content in plum. For apple (Malus domestica), while the absolute amounts of Pro content differed from those of the two Prunus species, this species accumulated Pro during the spring warming/regrowth. These results suggest that Pro accumulation in response to higher temperatures during the spring regrowth is a more general phenomenon across Rosaceae fruit trees, and although peach shoots may accumulate Pro via the ornithine pathway during spring regrowth, there was no evidence for this in plum and apple.

A composite film was formed with PVA by the loading of nano composite material polyaniline and nano SnO 2 (PANI/SnO2). The nanocomposite material was synthesized in the presence of nano SnO 2 with hydrochloric acidic solution by the chemical oxidative polymerization of aniline using ammonium peroxodisulfate as the oxidant. The characterization of the composite film was done by scanning electron microscopy (SEM) and electrical (dc, σ dc ) conductivity. As the nanocomposite material of PANI and nano SnO2 was synthesized in situ polymerization technique which was giving flower type structure and I-V characteristics represents non linear behaviour.

We report the morphological and electrical study of a composite of polyvinyl alcohol (PVA) and nanotitanium dioxide (TiO2-50 nm) in conducting polymer polyaniline (PANI). The composite was synthesized using in-situ polymerization technique. The composite was characterized in terms of morphology and electrical properties using scanning electron microscopy and DC electrical conductivity (𝜎dc). We observed that the DC electrical conductivity of the composite film increased with increasing the loading of nanocomposite material from 20 % to 40 % into PVA stabilizer. The DC conductivity results showed that the molecular chain contribution of the nanocomposite material (nano-TiO2+ PANI) was the prominent carrier in the composite film made of the nanocomposite and PVA stabilizer.

Dehydrins are a family of plant proteins that accumulate in response to dehydration stresses, such as low temperature, drought, high salinity, or during seed maturation. We have previously constructed cDNA libraries from Rhododendron catawbiense leaves of naturally non-acclimated (NA; leaf LT50, temperature that results in 50% injury of maximum, approximately −7°C) and cold-acclimated (CA; leaf LT50 approximately −50°C) plants and analyzed expressed sequence tags (ESTs). Five ESTs were identified as dehydrin genes. Their full-length cDNA sequences were obtained and designated as RcDhn 1-5. To explore their functionality vis-à-vis winter hardiness, their seasonal expression kinetics was studied at two levels. Firstly, in leaves of R. catawbiense collected from the NA, CA, and de-acclimated (DA) plants corresponding to summer, winter and spring, respectively. Secondly, in leaves collected monthly from August through February, which progressively increased freezing tolerance from summer through mid-winter. The expression pattern data indicated that RcDhn 1-5 had 6- to 15-fold up-regulation during the cold acclimation process, followed by substantial down-regulation during deacclimation (even back to NA levels for some). Interestingly, our data shows RcDhn 5 contains a histidine-rich motif near N-terminus, a characteristic of metal-binding dehydrins. Equally important, RcDhn 2 contains a consensus 18 amino acid sequence (i.e., ETKDRGLFDFLGKKEEEE) near the N-terminus, with two additional copies upstream, and it is the most acidic (pI of 4.8) among the five RcDhns found. The core of this consensus 18 amino acid sequence is a 11-residue amino acid sequence (DRGLFDFLGKK), recently designated in the literature as the F-segment (based on the pair of hydrophobic F residues it contains). Furthermore, the 208 orthologs of F-segment-containing RcDhn 2 were identified across a broad range of species in GenBank database. This study expands our knowledge about the types of F-segment from the literature-reported single F-segment dehydrins (FSKn) to two or three F-segment dehydrins: Camelina sativa dehydrin ERD14 as F2S2Kn type; and RcDhn 2 as F3SKn type identified here. Our results also indicate some consensus amino acid sequences flanking the core F-segment in dehydrins. Implications for these cold-responsive RcDhn genes in future genetic engineering efforts to improve plant cold hardiness are discussed.

Our previous study revealed that proline (Pro) accumulated in peach trees when cold-acclimated shoots were exposed to higher temperatures. In this study, we determined whether such Pro accumulation...

To gain a better understanding of the cold acclimation progression in blueberry, we investigated the proteome-level changes that occur in flower buds with increasing exposure to chilling temperatures using the 2D-DIGE technique. From this procedure, 104 protein spots were found to be differentially expressed. These proteins, identified by mass spectrometry, were compared to those previously found on 1-D protein gels and to differentially expressed transcripts from an earlier transcriptome study. The most highly induced proteins corresponded to previously described dehydrins. Approximately half of the changes in the proteome reflected similar changes in the transcriptome. In addition, from 2D-DIGE, different quantitative patterns of protein induction and suppression were found. The largest differences occurred during the transition from the first to the second stage of cold acclimation, which corresponded to timing of the largest increase in cold hardiness. This, with qualitative differences affecting the regulation of several functional groups, suggest as a whole that plants are able to monitor changes in the environment and then respond by modulating their proteome accordingly. Major pathways increasing in abundance included stress-related proteins, carbohydrate/energy metabolism, amino acid metabolism, biosynthesis of phenolic compounds and gene expression regulation. On the other hand, pathways decreasing in abundance consisted of stress-related proteins, photosynthetic proteins and cell growth and structural components. Their possible implication in the development of cold hardiness is discussed.

Significant advances have been made in our understanding of the regulation of cold hardiness. The existence of numerous biophysical and biochemical adaptive mechanisms in perennial woody plants and the complexity their regulation has made the development of methods for managing and improving cold hardiness in perennial woody plants has been very difficult. This may be partially attributed to viewing cold hardiness as a single dimensional response, rather than as a complex phenomenon, involving different mechanisms (avoidance and tolerance), different stages (mid-winter vs. late winter), and having an intimate overlap with the genetic regulation of dormancy. In particular separating the molecular regulation of cold hardiness from growth processes has been challenging. ICE and C-repeat binding factor (CBF), transcription factors (Inducer of CBF expression and CRT-binding factor) have been shown to be an important aspect in the regulation of cold-induced gene expression. Evidence has emerged, however, that they are also intimately involved in the regulation of growth, flowering, dormancy, and stomatal development. This evidence includes the presence of CBF binding motifs in genes regulating these processes, or through cross-talk between the pathways that regulate them. Recent changes in climate that have resulted in erratic episodes of unseasonal warming followed by more seasonal patterns of low temperatures has also highlighted the need to better understand the genetic and molecular regulation of deacclimation, a topic of research that is only more recently being addressed. Environmentally-induced epigenetic regulation of stress responses and seasonal processes such as cold acclimation, deacclimation, and dormancy have been documented but are still poorly understood. Advances in the ability to efficiently generate large DNA and RNA datasets and genetic transformation technologies have greatly increased our ability to explore the regulation of gene expression and explore genetic diversity. Greater knowledge of the interplay between epigenetic and genetic regulation of cold hardiness, along with the application of advanced genetic analyses, such as genome-wide-association-studies (GWAS), are needed to develop strategies for addressing the complex processes associated with cold hardiness in woody plants. A cautionary note is also indicated regarding the time-scale needed to examine and interpret plant response to freezing temperatures if progress is to be made in developing effective approaches for manipulating and improving cold hardiness.

With the addition of inorganic spherical particles to polymers allows the modification of the polymers physical properties in the polymer matrix. This review article covers considerations on special the aspects of TiO2 and PVA composite materials in polyaniline during the polymerization. Classical composite properties, as thermo mechanical, conductive as well as mechanical properties will be summarized. Finally, typical existing and potential applications will be shown with the focus on new and innovative applications, like in environment systems and energy systems.

Thermal Properties of Polyaniline (PANI) Composite Film Synthesized by Nanocomposite Material TiO 2 and Polyvinyl Alcohol has been investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dc conductivity analyses. The results clearly demonstrate that the composite film of nanocomposite material (encapsulated nano-TiO 2 and Polyaniline) and poly-vinyl alcohol are more stable at higher temperature than pure polyaniline.

Salicylic acid (SA)-treatment has been reported to improve plant tolerance to various abiotic stresses. However, its effect on freezing tolerance has not been well investigated. We investigated the effect of exogenous SA on freezing tolerance of spinach (Spinacia oleracea L.) leaves. We also explored if nitric oxide (NO) and/or hydrogen peroxide (H2O2)-mediation was involved in this response, since these are known as primary signaling molecules involved in many physiological processes. A micro-centrifuge tube-based system used to apply SA to petiolate spinach leaves (0.5 mM over 4-d) was effective, as evident by SA content of leaf tissues. SA-treatment did not hamper leaf growth (fresh and dry weight; equatorial and longitudinal length) and was also not significantly different from 25% Hoagland controls vis-a-vis growth. SA application significantly improved freezing tolerance as evidenced by reduced ion-leakage and alleviated oxidative stress (lower accumulation of O2·- and H2O2) following freeze-thaw stress treatments (-6.5, -7.5, and -8.5 °C). Improved freezing tolerance of SA-treated leaves was paralleled by increased proline and ascorbic acid (AsA) accumulation. A 9-d cold acclimation (CA) treatment also improved leaf freezing tolerance (compared to non-acclimated control) and was accompanied by accumulation of SA and proline. Our results indicate that increased freezing tolerance may be associated with accumulation of compatible solutes (proline) and antioxidants (AsA). Notably, the beneficial effect of SA on freezing tolerance was abolished when either H2O2- or NO-scavenger (1 μM N-acetylneuraminic acid, NANA or 100 μM hemoglobin, HB, respectively) was added to SA as pretreatment. Our data suggest that SA-induced freezing tolerance in spinach may be mediated by NO and H2O2 signaling.

Adaptations to freezing air temperature in temperate understory species of Rhododendron include physiological processes, anatomical changes, and thermonastic leaf movements. Leaves roll transversely and leaf-lamina angle decreases in relation to horizontal as temperatures decrease below a critical freezing temperature. Within the genus Rhododendron, tolerance of cold conditions is greater in species with thermonastic leaf movements than species without. The leaf movements protect critical physiological processes such as photosynthesis from damage due to the synergistic effects of cold temperatures, and high light common to winter conditions in temperate forests. In particular, the absence of these leaf movements increases photoinhibition, and species that lack these adaptations exhibit distinctly different physiological and anatomical mechanisms of photo-protection during cold conditions. The biomechanical or physiological causes for thermonastic leaf movements have been difficult to resolve because of the lack of distinctive anatomical and morphological features associated with these leaf movements. Nevertheless, it is firmly established that the lower the petiole turgor potential the lower the leaf-lamina angle in relation to horizontal. However, the cause of leaf rolling is unclear. In this study, experiments on sectioned leaves implicate both longitudinal and lateral thermonastic rolling forces, likely driven by water redistribution between apoplast and symplast, and regulated by aquaporins. This should result in abaxial–adaxial differential turgor pressures that vary markedly along the mediolateral direction. We postulate that the combined effect of the leaf morphology, anisotropy in rolling forces and the geometrical constraints due to the relatively stiff midrib causes leaf rolling, consistent with the mechanics of a thin plate with anisotropic spontaneous curvature. We expect a correlation between the rolling forces and veination microstructure that remains to be explored for a complete understanding of leaf adaptations to freezing in understory evergreen Rhododendron species, as well as more general thermonastic responses.

‘Duration of freezing’ at a given treatment temperature can significantly influence the laboratory evaluation of plant freeze–thaw stress tolerance (FTST) by potentially affecting the extent of freeze–thaw injury and, therefore, also the ability of post-thaw recovery. The objective of this study was to compare the extent of freeze–thaw injury, estimated by various physiological indicators [electrolyte leakage, photosystem II efficiency ( F v / F m ), accumulation of reactive oxygen species (O 2 − and H 2 O 2 ), and malondialdehyde (MDA) accumulation], in the leaves of spinach ( Spinacia oleracea L.) when exposed for various durations (0.5, 3.0, 5.5, and 10.5 h) of freezing. Leaf LT 50 was first determined (approximately −5.5 °C) and two sub-lethal temperatures, −4.0 and −4.5 °C, were selected as the freezing stress. The ability of post-thaw recovery was compared in leaves stressed for shorter versus longer durations at −4.5 °C. All measurements indicated that injury progressively increased with longer freezing durations. While no injury was observed (based on the electrolyte leakage) at −4 °C for 0.5 h, tissues were ∼50% injured by the same temperature when frozen for 10.5 h. Moreover, −4.5 °C stress appears as sub-lethal at 3 h of freezing (∼30% injury), but, injury doubled (and exceeded the LT 50 threshold) after additional 2.5 h at this temperature. Finally, leaves were identically injured to a recoverable point (∼30% injury) when frozen for 3 h at either −4 °C or −4.5 °C while 5.5 h of freezing at −4.5 °C caused irreversible injury but no change for −4.0 °C. Our results and corresponding discussion highlight the importance of considering ‘duration of freezing’ as one of the factors for objective interpretation of FTST/LT 50 data derived from artificial freeze–thaw tests.

Supply chain management, in recent times, has emerged as the basis in many industries (small or large) for creating the integrated relationship between suppliers and customers. Due to continuous growth in last year in supply chain management the environment has become competitive. So in order to respond to competitive pressures companies need to know and understand the new trends in SCM. This paper focuses the emerging trends of SCM in current scenario, and it provides broader awareness of SCM concepts. It addresses this need, by critically reviewing the current status of SCM in Indian context and its point of difference with other countries like China. Managing the Supply chain by making use of I.T. services has paved a new way of confiscating the uncertainty and enhancing the customer service and thus creating a competitive edge.