Tissue and Life Stage Specificity of Glutathione S-Transferase Expression in the Hessian Fly, Mayetiola destructor: Implications for Resistance to Host Allelochemicals

Two new Delta and Sigma glutathione S-transferases (GSTs) in the Hessian fly, Mayetiola destructor (Diptera: Cecidomyiidae), were characterized and transcription profiles described. The deduced amino acid sequences for the two M. destructor Delta GSTs (MdesGST-1 and MdesGST-3) showed high similarity with other insect Delta GSTs including the conserved catalytic serine residue. The deduced amino acid sequence for the M. destructor Sigma GST (MdesGST-2) showed high similarity with other insect Sigma GSTs including the conserved glutathione and substrate binding sites. Quantitative tissue expression analysis showed that mRNA levels for MdesGST-1 were predominant in fat body, whereas for MdesGST-2 and MdesGST-3 expression was predominant in the midgut. Temporal expression during development showed peak mRNA levels for MdesGST-1 during larval development, but in the pupal stage for MdesGST-2. MdesGST-3 showed a constitutive expression pattern throughout development. M. destructor feeds on wheat, and expression analysis after feeding indicated that mRNA levels for MdesGST-1 were significantly higher in incompatible interactions in which larvae fed on resistant wheat, while MdesGST-3 was significantly higher in compatible interactions when larvae fed on susceptible wheat. MdesGST-2 showed an equivalent expression pattern during both interactions. These results suggest that the M. destructor Delta GSTs are important in detoxifying wheat allelochemicals during feeding, while Sigma GST participates in metabolism of endogenous substrates

Transcriptomic Signatures of Ash (Fraxinus spp.) Phloem

Ash (Fraxinus spp.) is a dominant tree species throughout urban and forested landscapes of North America (NA). The rapid invasion of NA by emerald ash borer (Agrilus planipennis), a wood-boring beetle endemic to Eastern Asia, has resulted in the death of millions of ash trees and threatens billions more. Larvae feed primarily on phloem tissue, which girdles and kills the tree. While NA ash species including black (F. nigra), green (F. pennsylvannica) and white (F. americana) are highly susceptible, the Asian species Manchurian ash (F. mandshurica) is resistant to A. planipennis perhaps due to their co-evolutionary history. Little is known about the molecular genetics of ash. Hence, we undertook a functional genomics approach to identify the repertoire of genes expressed in ash phloem.Using 454 pyrosequencing we obtained 58,673 high quality ash sequences from pooled phloem samples of green, white, black, blue and Manchurian ash. Intriguingly, 45% of the deduced proteins were not significantly similar to any sequences in the GenBank non-redundant database. KEGG analysis of the ash sequences revealed a high occurrence of defense related genes. Expression analysis of early regulators potentially involved in plant defense (i.e. transcription factors, calcium dependent protein kinases and a lipoxygenase 3) revealed higher mRNA levels in resistant ash compared to susceptible ash species. Lastly, we predicted a total of 1,272 single nucleotide polymorphisms and 980 microsatellite loci, among which seven microsatellite loci showed polymorphism between different ash species.The current transcriptomic data provide an invaluable resource for understanding the genetic make-up of ash phloem, the target tissue of A. planipennis. These data along with future functional studies could lead to the identification/characterization of defense genes involved in resistance of ash to A. planipennis, and in future ash breeding programs for marker development

Transcriptomics of the Bed Bug (Cimex lectularius)

BACKGROUND: Bed bugs (Cimex lectularius) are blood-feeding insects poised to become one of the major pests in households throughout the United States. Resistance of C. lectularius to insecticides/pesticides is one factor thought to be involved in its sudden resurgence. Despite its high-impact status, scant knowledge exists at the genomic level for C. lectularius. Hence, we subjected the C. lectularius transcriptome to 454 pyrosequencing in order to identify potential genes involved in pesticide resistance. METHODOLOGY AND PRINCIPAL FINDINGS: Using 454 pyrosequencing, we obtained a total of 216,419 reads with 79,596,412 bp, which were assembled into 35,646 expressed sequence tags (3902 contigs and 31744 singletons). Nearly 85.9% of the C. lectularius sequences showed similarity to insect sequences, but 44.8% of the deduced proteins of C. lectularius did not show similarity with sequences in the GenBank non-redundant database. KEGG analysis revealed putative members of several detoxification pathways involved in pesticide resistance. Lamprin domains, Protein Kinase domains, Protein Tyrosine Kinase domains and cytochrome P450 domains were among the top Pfam domains predicted for the C. lectularius sequences. An initial assessment of putative defense genes, including a cytochrome P450 and a glutathione-S-transferase (GST), revealed high transcript levels for the cytochrome P450 (CYP9) in pesticide-exposed versus pesticide-susceptible C. lectularius populations. A significant number of single nucleotide polymorphisms (296) and microsatellite loci (370) were predicted in the C. lectularius sequences. Furthermore, 59 putative sequences of Wolbachia were retrieved from the database. CONCLUSIONS: To our knowledge this is the first study to elucidate the genetic makeup of C. lectularius. This pyrosequencing effort provides clues to the identification of potential detoxification genes involved in pesticide resistance of C. lectularius and lays the foundation for future functional genomics studies

<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Process optimization of sandalwood (<i style="mso-bidi-font-style:normal">Santalum album</i>) oil extraction by subcritical carbon dioxide and conventional techniques</span>

290-297Sandalwood oil has been extracted using subcritical state carbon dioxide (SC-CO2) at 200 bars and 28oC using the two experimental conditions, and the fractionation of the extract is analyzed intermittently. Comparative studies with regards to extraction using steam distillation, hydro distillation, soxhlet extraction and pre-treatment studies have also been carried out. All these studies reveal that the subcritical carbon dioxide extraction is much more efficient in terms of physical properties of the oil as compared to commercial sandalwood oil. Acid value of the liquid CO2 extracted oil is found to be the best next to the value of ethyl alcohol extracted oil. SC-CO2 yields 4.11% of oil in the first hour, 1.21% in second hour, 0.89% in third hour and 0.30% finally in the fourth hour. The first hour gives α-santalene (0.55%), β-santalene (1.30%), α-santalol (51.30%), β-santalene (27.94%); second hour gives 0.48, 1.08, 54.50, 28.16% third and fourth hour give 1.00, 1.92, 50.27, 26.18% and 1.14, 2.17, 51.99, 26.76% respectively. Benzene extraction yields 3.01% of an absolute out of 6.30 g of concrete, diethyl ether yields 2.58% of an absolute out of 5.25 g of concrete, EtOH yields 3.70% of an absolute out of 10.90 g of concrete (under the 5 hour of process time). Hydro distillation (alkaline treated) yields 2.68% of sandalwood oil in 48 h, steam distillation gives 1.60% of sandalwood oil in 10 h of process time. Yield of 4.11% is obtained by SC-CO2 only

Reactive melt infiltration processing of biomorphic Si-Mo-C ceramics from wood

Different kinds of natural wood specimens (beech, pine, and rattan) were converted to biomorphic, microcellular Si-Mo-C ceramics by reactive melt infiltration processing. During processing at 1500 degrees C under vacuum the carbon of the pyrolyzed native preforms reacted with Si of the infiltrating Si-Mo eutectic melt (90.4 wt% Si). The resulting materials have fractional densities of > 90%, and contained silicon carbide (SiC), MoSi2, in addition to unreacted Si and carbon. The residual carbon remains covered by SiC. The conversion process retains the microcellular morphology of the parent wood tissue. Depending on the initial morphology of the different kinds of wood, reactive melt infiltration processing of Si-Mo-C ceramics can be used to manufacture fight weight materials with low density but adequate strength for wide ranging applications where anisotropic behavior is required

Supply chain inventory model for deteriorating items under two-level credit policy in declining market

In this paper, an attempt is made to derive the retailer's inventory policy for deteriorating items under two levels of trade credit in declining market in supply chain environment. It is assumed that the retailer is a powerful decision maker. Supplier offers credit period to the retailer which in turn, partially offered to the customers by the retailer. The objective is to minimise the total cost of the retailer's inventory system with respect to the cycle time. An easy-to-use algorithm is given to decide the best policy. The numerical examples are given to illustrate the developed model and managerial issues are derived.deterioration; partial trade credit; demand declining markets; supply chain management; SCM; inventory modelling; deteriorating items; credit policy; inventory policy.