Towards better insect management strategy: restriction of insecticidal gene expression to biting sites in transgenic cotton

Most of the commercialized Bt crops express cry genes under 35S promoter that induces strong gene expression in all plant parts. However, targeted foreign gene expression in plants is esteemed more important as public may be likely to accept ‘less intrusive’ expression of transgene. We developed plant expression constructs harboring cry1Ac gene under control of wound-inducible promoter (AoPR1) to confine Bt gene expression in insect wounding parts of the plants in comparison with cry1Ac gene under the control of 35S promoter. The constructs were used to transform four Turkish cotton cultivars (GSN-12, STN-468, Ozbek-100 and Ayhan-107) through Agrobacterium tumefaciens strains GV2260 containing binary vectors p35SAcBAR.101 and AoPR1AcBAR.101 harboring cry1Ac gene under control of 35S and AoPR1, respectively. Phosphinothricin (PPT) was used at concentration of 5 mg L^?1 for selection of primary transformants. The primary transformants were analyzed for transgene presence and expression standard molecular techniques. The transformants exhibited appreciable mortality rates against larvae of Spodoptera exigua and S. littoralis. It was found that mechanical wounding of T ₁ transgenic plants was effective in inducing expression of cry1Ac protein as accumulated levels of cry1Ac protein increased during post-wounding period. We conclude that use of wound-inducible promoter to drive insecticidal gene(s) can be regarded as a valuable insect-resistant management strategy since the promoter activity is limited to insect biting sites of plant. There is no Bt toxin accumulation in unwounded plant organs, seed and crop residues, cotton products and by-products, thus minimizing food and environmental concerns.     

Chitosan film containing fucoidan as a wound dressing for dermal burn healing: Preparation and in vitro/in vivo evaluation

The aim of this study was to develop chitosan film containing fucoidan and to investigate its suitability for the treatment of dermal burns on rabbits. Porous films, thickness between 29.7 and 269.0 μm, were obtained by the solvent dropping method. Water vapor permeability (3.3–16.6/0.1 g), the swelling (0.67–1.77 g/g), tensile strength (7.1–45.8 N), and bioadhesion (0.076–1.771 mJ/cm²) of the films were determined. The thinnest films were obtained with the lowest chitosan concentration (P<.05). The water absorption capacity of the films sharply increased with the freeze-drying technique. The film having the thickness of 29.7 μm showed the highest amount of moisture permeability (16.6 g/0.1 g). Higher chitosan concentration significantly increased tensile strength of the films (P<.05). Using higher concentration of lactic acid made films more elastic and applicable, and these films were selected for in vivo studies. Seven adult male New Zealand white rabbits were used for the evaluation of the films on superficial dermal burns. Biopsy samples were taken at 7, 14, and 21 days after wounding, and each wound site was examined macroscopically and histopathologically. After 7 days treatment, fibroplasia and scar were observed on wounds treated with fucoidan-chitosan film. The best regenerated dermal papillary formation, best reepithelization, and the fastest closure of wounds were found in the fucoidan-chitosan film treatment group after 14 days compared with other treatment and control groups. It can be concluded that fucoidan-chitosan films might be a potential treatment system for dermal burns and that changing formulation variables can modulate the characterizations of the films. Published: May 24, 2007     

Phanerochaete chrysosporium soluble proteome as a prelude for the analysis of heavy metal stress response

A 2-D reference map in pI range 3-10 was constructed for the soluble protein fraction of Phanerochaete chrysosporium growing vegetatively under standard conditions. Functional annotation could be made for 517 spots out of 720 that were subjected to MALDI-TOF-MS analysis, according to the specific accession numbers from the P. chrysosporium genomic database. Further analysis of the data revealed 314 distinct ORFs, 118 of which yielded multiple spots on the master gel. Functional classification of the proteins was made according to the eukaryote orthologous groups defined in the organism's genome website. The functional class of PTMs, protein turnover and chaperones was represented with the highest number (63) of the identified ORFs. Six proteins were assigned to the hypothetical proteins and 29 were predicted to have a signal peptide sequence. Subcellular localization predictions were also made for the identified proteins. Of the protein spots detected on the master gel, 380 were found to be probably phosphorylated and 96 of these matched to the identified proteins. The reference map was efficiently used in the identification of the proteins differentially expressed under cadmium and copper stress. Three new ribosomal proteins as well as zinc-containing alcohol dehydrogenase, glucose-6-phosphate isomerase, flavonol/cinnamoyl-CoA reductase, H+-transporting two-sector ATPase, ribosomal protein S7, ribosomal protein S21e, elongation factor EF-1 alpha subunit were demonstrated as the most strongly induced.     

Endometrial stem cell transplantation in MPTP‐ exposed primates: an alternative cell source for treatment of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic neurons in the substantia nigra. Cell‐replacement therapies have emerged as a promising strategy to slow down or replace neuronal loss. Compared to other stem cell types, endometrium‐derived stem cells (EDSCs) are an attractive source of stem cells for cellular therapies because of their ease of collection and vast differentiation potential. Here we demonstrate that endometrium‐derived stem cells may be transplanted into an MPTP exposed monkey model of PD. After injection into the striatum, endometrium‐derived stem cells engrafted, exhibited neuron‐like morphology, expressed tyrosine hydroxylase (TH) and increased the numbers of TH positive cells on the transplanted side and dopamine metabolite concentrations in vivo. Our results suggest that endometrium‐derived stem cells may provide a therapeutic benefit in the primate model of PD and may be used in stem cell based therapies.     

Antiproliferative and newly attributed apoptotic activities from an invasive marine alga: Caulerpa racemosa var. cylindracea

Caulerpa racemosa (Forsskål) is a green marine alga which spreads from tropical to warm-water regions. Due to having invasive capacity C. racemosa var. cylindracea is a well-known biological pollution in Mediterranean Sea. One of the most important secondary metabolites of C. racemosa is Caulerpenyne (CPN). In the present study, antiproliferative and apoptotic effects of C. racemosa var. cylindracea extract and purified CPN on two well-known neuroblastoma cell lines, SHSY5Y and Kelly, are investigated. The antiproliferative and, additionally, newly attributed apoptotic effects of both C. racemosa var. cylindracea extract and purified CPN on SHSY5Y and Kelly cell lines have been shown in the present study. IC₅₀ values are 0.59 ± 0.06; 1.06 ± 0.23 g wet alga/methanol and 5.64 ± 0.09; 6.02 ± 0.09 μM CPN for C. racemosa var. cylindracea extract and purified CPN on SHSY5Y and Kelly cell lines, respectively. Percentages of apoptotic cells of SHSY5Y and Kelly in 0, 0.1 and 1 μM CPN conditions were 1.00 ± 0.71, 3.00 ± 0.71 and 49.40 ± 3.78, 39.60 ± 6.19 and 78.00 ± 2.74, 69.40 ± 3.78, respectively. In conclusion, the present study shows the antiproliferative effect of C. racemosa var. cylindracea extract and newly attributed apoptotic effects of C. racemosa var. cylindracea this extract. Compared to other alkylating anticancer drugs, CPN and also C. racemosa var. cylindracea extract might be considered as an alternative native source of antitumor drugs. Inasmuch as both C. racemosa extract and CPN have shown both antiproliferative and apoptotic effects on SHSY5Y and Kelly cell lines, the CPN and CPN derivatives might be considered as multifunctional agents in cell metabolism.     

The investigation on accumulation levels of proline and stress parameters of the maize (<Emphasis Type="Italic">Zea</Emphasis> <Emphasis Type="Italic">mays</Emphasis> L.) plants under salt and water stress

The present study was carried out to determine interactive and comparative effects of salinity and water stress on growth, proline accumulation, chlorophyll, carotenoid and macro nutrient content and antioxidative enzymes such as superoxide dismutase (SOD), guaiacol peroxidase (POX), and polyphenol oxidase (PPO) in hydroponically grown maize (Zea mays L.cv DKC647) plants. Plants were treated two salt (NaCl) concentrations and polyethylene glycol 6000 (PEG 6000) to create water stress. The results obtained from this experiment show that high salinity reduced growth through decreasing shoot and root dry and fresh weight, chlorophyll, and carotenoid content, but PEG treatment had no significant effect on this parameters. Under NaCl and PEG 6000 treatment, uptake and translocation of mineral nutrients changed drastically. The high presence of Na⁺ in nutrient solution affected considerably the plant nutritional requirement, especially influencing the uptake of Ca²⁺ and K⁺, which were restricted for competition. Proline accumulation, and SOD, POX and PPO activities were increased with the increasing intensity of NaCl stress, but PEG 6000 treatment in addition to NaCl had more significant effect on this enzyme activities. These results suggest that maize plants may be increased proline content to maintain osmotic adjustment and increased the activity of antioxidant enzymes to have a better protection against active oxygen species (AOS) under salt and water stress.     

Reactive Oxygen Species Production in Wheat Roots Is Not Linked with Changes in H+ Fluxes During Acidic and Aluminium Stresses

Aluminium stress induces peroxidation of lipids in the plasma membrane, the effect akin to that caused by reactive oxygen species (ROS). ROS have recently been proposed as regulators of redox-dependent ion transport across the plasma membrane during biotic and abiotic stresses, thus contributing to the plant defence system. The aim of this study was to discover whether ROS production is linked to redox-dependent H⁺ transport system located at the plasma membranes of two near-isogenic lines of wheat (Triticum aestivum L., ET8 = Al-resistant, ES8 = Al-sensitive).The activities of NADPH-dependent ROS synthase and SOD were increased in both wheat lines 15 and 30 min after Al treatments. However, the ROS production was also increased under acidic stress. There was no difference between the two wheat lines in the root-cell plasma membrane capacity to efflux H⁺ in response to potassium ferricyanide after Al and acidic treatments. In ET8, both stresses led to increases in ROS production and H⁺ influx.ROS production in wheat seedlings was activated primarily by low pH exposure rather than by the Al stress. ROS production and breakdown in wheat seedlings under Al and acidic stresses appear to be linked to the intracellular metabolic changes rather than to the increased activity of plasma membrane-based NADPH-dependent ROS synthase.Key Words: ion fluxes, reactive oxygen species (ROS), redox system, superoxide dismutase (SOD), Triticum aestivum L., wheat     

Multiple QTL-effects of wheat Gpc-B1 locus on grain protein and micronutrient concentrations

Micronutrient malnutrition afflicts over three billion people worldwide and the numbers are continuously increasing. Developing genetically micronutrient-enriched cereals, which are the predominant source of human dietary, is essential to alleviate malnutrition worldwide. Wheat chromosome 6B derived from wild emmer wheat [ Triticum turgidum ssp. dicoccoides (Körn.) Thell] was previously reported to be associated with high Zn concentration in the grain. In the present study, recombinant chromosome substitution lines (RSLs), previously constructed for genetic and physical maps of Gpc-B1 (a 250-kb locus affecting grain protein concentration), were used to identify the effects of the Gpc-B1 locus on grain micronutrient concentrations. RSLs carrying the Gpc-B1 allele of T. dicoccoides accumulated on average 12% higher concentration of Zn, 18% higher concentration of Fe, 29% higher concentration of Mn and 38% higher concentration of protein in the grain as compared with RSLs carrying the allele from cultivated wheat ( Triticum durum ). Furthermore, the high grain Zn, Fe and Mn concentrations were consistently expressed in five different environments with an absence of genotype by environment interaction. The results obtained in the present study also confirmed the previously reported effect of the wild-type allele of Gpc-B1 on earlier senescence of flag leaves. We suggest that the Gpc-B1 locus is involved in more efficient remobilization of protein, zinc, iron and manganese from leaves to the grains, in addition to its effect on earlier senescence of the green tissues.     

Immobilization of polyphenol oxidase in conducting copolymers and determination of phenolic compounds in wines with enzyme electrodes

Polyphenol oxidase (PPO) was immobilized in copolymers of thiophene functionalized menthyl monomer (MM) with pyrrole. Immobilization of enzyme was performed via entrapment in conducting copolymers during electrochemical polymerization of pyrrole. Maximum reaction rates, Michaelis-Menten constants and temperature, pH and operational stabilities of enzyme electrodes were investigated. Total amount of phenolic compounds in red wines of Turkey were analyzed by using these electrodes.     

Complications after reconstruction by plate and soft-tissue free flap in composite mandibular defects and secondary salvage reconstruction with osteocutaneous flap

Reconstruction of composite defects of the mandible is a challenging problem. Although the use of an osteocutaneous free flap, alone or in combination with another soft-tissue free flap, is generally accepted to be optimal, the bony reconstruction is sometimes undervalued, especially when the cancer is advanced. In such situations, reconstruction is often performed with a reconstruction plate covered with a soft-tissue free flap. Between January of 1997 and July of 2000, 80 patients with composite or extensive composite oromandibular defects underwent treatment with a reconstruction plate and a soft-tissue free flap. All of the patients were male, and the ages of the patients at the time of treatment ranged from 32 to 78 years (mean, 51 years). Tumors were classified as stage IV in 56 patients (70 percent), whereas the remaining 24 patients (30 percent) had recurrent carcinomas. The titanium mandibular reconstruction system manufactured by Stryker (Freiburg, Germany) was used to bridge the mandibular defects. The soft-tissue free flaps used for wound and plate coverage were as follows: anterolateral thigh flap (n = 75), radial forearm flap (n = 3), transverse rectus abdominis myocutaneous flap (n = 1), and tensor fasciae latae flap (n = 1). Five patients with recurrent carcinomas and 10 with stage IV carcinomas (18.75 percent) died 2 to 6 months after the operation and were excluded from the study. The remaining 65 patients were monitored for an average follow-up period of 22 months (range, 6 to 40 months). During that period, one or more complications occurred for 45 patients (69.2 percent). Plate exposure was the most common complication and was observed for 30 patients (46.15 percent). Twenty of the 65 patients (30.8 percent) required secondary salvage reconstruction with a fibula osteoseptocutaneous flap. The decision to perform a secondary salvage procedure was based on the general health of the patient, the extent of local disease, and the severity of the complications. Patients underwent salvage operations after an average of 11.5 months (range, 6 to 26 months). The major reasons for the second operation were as follows: reconstruction plate exposure (n = 12), soft-tissue deficiency and mandibular contour deformation of the lateral face (n = 7), intraoral contracture and lack of a gingivobuccal sulcus (n = 6), trismus (n = 4), and osteoradionecrosis of the mandible (n = 2). The total flap survival rate was 90 percent (18 of 20 free flaps). In two cases, the skin paddles of the fibula osteoseptocutaneous flaps exhibited partial failure and were revised with pedicled pectoralis major and deltopectoral flaps. The reconstruction plate and free soft-tissue flap procedure for the reconstruction of composite defects of the oromandibular region has many late complications, which eventually necessitate reconstruction of the mandible with an osteocutaneous free flap.