Characterization of <Emphasis Type="Italic">VvPAL-like</Emphasis> promoter from grapevine using transgenic tobacco plants

A 2000-bp 5′-flanking region of VvPAL-like was isolated from ‘Summer Black’ grapevine by PCR amplification, named pVvPAL-like. To gain a better understanding of the expression and regulatory mechanism of VvPAL-like, a chimeric expression unit consisting of the β-glucuronidase (GUS) reporter gene under the control of a 2000-bp fragment of the VvPAL-like promoter was transformed into tobacco via Agrobacterium tumefaciens. Histochemical staining showed that the full-length promoter directs efficient expression of the reporter gene in cotyledons and hypocotyls, stigma, style, anthers, pollen, ovary, trichomes, and vascular bundles of transgenic plants. A series of 5′ progressive deletions of the promoter revealed the presence of a negative regulatory region (?424 to ?292) in the VvPAL-like promoter. Exposure of the transgenic tobacco plants to various abiotic stresses demonstrated that the full-length construct could be induced by light, copper (Cu), abscisic acid (ABA), indole-3-acetic (IAA), methyl jasmonate (MeJA) (N-1-naphthylphthalamic acid), ethylene, and drought. Furthermore, the ethylene-responsive region was found to be located in the ?1461/?930 fragment, while the element(s) for the MeJA-responsive expression may be present in the ?424/?292 region in the VvPAL-like promoter. These findings will help us to better understand the molecular mechanisms by which VvPAL-like participates in biosynthesis of flavonoids and stress responses.     

Changes in Body Wall of Sea Cucumber (<Emphasis Type="Italic">Stichopus japonicus</Emphasis>) during a two-Step Heating Process Assessed by Rheology,LF-NMR,and Texture Profile Analysis

Sea cucumber (Stichopus japonicus) is regarded as a highly priced delicacy in Japan and China owing to its unique elasticity and palatability. Heating is an essential step to process sea cucumber with desired texture. In the present study, sea cucumber body wall was pre-heated at 40 °C, followed by post-heating at 80 °C. Changes in body wall were assessed by rheology, LF-NMR, and texture profile analysis. The small strain rheological analysis indicated that there were significant structural changes of body wall at about 40 °C during pre-heating. Large strain texture profile analysis and the storage modulus showed a good correlation. LF-NMR analysis displayed only one water population in samples pre-heated at 40 °C for up to 120 min, and the population did not change significantly with the heating duration. This demonstrated that structural changes and moisture loss from the inter collagen fibrils were not significant. As for samples post-heated at 80 °C, three distinct peaks were found and the T ₂ relaxation time and area of the bulk water decreased significantly, revealing significant changes of internal structures and loss of water-holding capacity. T ₂ parameters had a good correlation to texture profile analysis parameters for samples after both pre-heating and post-heating.     

Psychrophilic and psychrotrophic fungi: a comprehensive review

This article reviews the comparative diversity of psychrophilic and psychrotrophic fungi, their adaptability mechanisms for survival and potential applications in biotechnology and pharmaceuticals. Fungi are able to grow and survive at low temperature and exist widely in polar and non-polar habitats. These cold regions are known for very low temperature, high ultra violet-B radiation, frequent freeze and thaw cycles and low water and nutrient availability. Most of the fungi adapt to such harsh conditions by evolving various strategies in their metabolism and physiology. Psychrophilic and psychrotrophic fungi are of importance in biotechnological and pharmaceutical fields due to their diverse characteristics developed or evolved due to their adaptation and survival in extreme environments, like; production of cold-active enzymes, pharmaceutical or bioactive metabolites and exo-polysaccharides, have potential for bioremediation and can also be used as biofertilizer.     

Inhibiting Tyrosine Phosphorylation of Protein Kinase Cδ (PKCδ) Protects the Salivary Gland from Radiation Damage

Radiation therapy for head and neck cancer can result in extensive damage to normal adjacent tissues such as the salivary gland and oral mucosa. We have shown previously that tyrosine phosphorylation at Tyr-64 and Tyr-155 activates PKCδ in response to apoptotic stimuli by facilitating its nuclear import. Here we have identified the tyrosine kinases that mediate activation of PKCδ in apoptotic cells and have explored the use of tyrosine kinase inhibitors for suppression of irradiation-induced apoptosis. We identify the damage-inducible kinase, c-Abl, as the PKCδ Tyr-155 kinase and c-Src as the Tyr-64 kinase. Depletion of c-Abl or c-Src with shRNA decreased irradiation- and etoposide-induced apoptosis, suggesting that inhibitors of these kinases may be useful therapeutically. Pretreatment with dasatinib, a broad spectrum tyrosine kinase inhibitor, blocked phosphorylation of PKCδ at both Tyr-64 and Tyr-155. Expression of “gate-keeper” mutants of c-Abl or c-Src that are active in the presence of dasatinib restored phosphorylation of PKCδ at Tyr-155 and Tyr-64, respectively. Imatinib, a c-Abl-selective inhibitor, also specifically blocked PKCδ Tyr-155 phosphorylation. Dasatinib and imatinib both blocked binding of PKCδ to importin-α and nuclear import, demonstrating that tyrosine kinase inhibitors can inhibit nuclear accumulation of PKCδ. Likewise, pretreatment with dasatinib also suppressed etoposide and radiation induced apoptosis in vitro. In vivo, pre-treatment of mice with dasatinib blocked radiation-induced apoptosis in the salivary gland by >60%. These data suggest that tyrosine kinase inhibitors may be useful prophylactically for protection of nontumor tissues in patients undergoing radiotherapy of the head and neck.     

Phylogenetic analysis of Aedes species distributed in Taif Province,Saudi Arabia,based on mitochondrial COX1 sequences

As Aedes mosquitoes are the predominant carriers of arboviruses responsible for global dengue fever and chikungunya outbreaks, understanding their genetic diversity and population structure can enhance dengue prevention and vector control efforts. Although sympatric cryptic species have been acknowledged in Aedes species subgroups in Southeast Asia, little information is available regarding the occurrence and dispersal of cryptic Aedes species in Saudi Arabia. In the present investigation, we intend to analyze genetic variations and perform a phylogenetic study of sympatric Aedes samples collected from various locations in Taif Province, Saudi Arabia. The locus of mitochondrial DNA cytochrome c oxidase subunit 1 (COX1, analyzed with DNA barcoding) was utilized to determine genetic variance and to build phylogenetic trees. For species identification, the COX1 sequences of Aedes samples from Taif Province were compared with those of Aedes samples from GenBank (National Center for Biotechnology Information, NCBI). To identify phylogenetic relationships and genetic variability, phylogenetic trees were created using Taif Province samples, GenBank A. albopictus samples, and GenBank A. aegypti samples. The phylogenetic analysis revealed that some Taif samples (A3, A7, F2, F4, F1, A4, A1, F9 and F6) were closer to A. aegypti and A. albopictus samples from Africa and East Asia, especially Kenya and Malaysia. Whereas other samples (F9, F6, A4, F1 and A1) were closer to the GenBank A. aegypti samples KP843383 (Thailand), HM399357(Australia), MK533632 (Kenya), KX420460 (Kenya), KU495081 (Australia) and MF179160 (China) than the remaining Taif samples. Overall, our findings demonstrate that examining the genetic diversity and phylogenetic linkages of Aedes samples can aid in understanding the evolution of Aedes cryptic species in the western regions of Saudi Arabia.     

Proteomic analysis of bacterial-blight defense-responsive proteins in rice leaf blades

Plants exhibit resistance against incompatible pathogens, via localized and systemic responses as part of an integrated defense mechanism. To study the compatible and incompatible interactions between rice and bacteria, a proteomic approach was applied. Rice cv. Java 14 seedlings were inoculated with compatible (Xo7435) and incompatible (T7174) races of Xanthomonas oryzae pv. oryzae (Xoo). Cytosolic and membrane proteins were fractionated from the leaf blades and separated by 2-D PAGE. From 366 proteins analyzed, 20 were differentially expressed in response to bacterial inoculation. These proteins were categorized into classes related to energy (30%), metabolism (20%), and defense (20%). Among the 20 proteins, ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (RuBisCO LSU) was fragmented into two smaller proteins by T7174 and Xo7435 inoculation. Treatment with jasmonic acid (JA), a signaling molecule in plant defense responses, changed the level of protein accumulation for 5 of the 20 proteins. Thaumatin-like protein and probenazole-inducible protein (PBZ) were commonly up-regulated by T7174 and Xo7435 inoculation and JA treatment. These results suggest that synthesis of the defense-related thaumatin-like protein and PBZ are stimulated by JA in the defense response pathway of rice against bacterial blight.     

Inhibitory effect of flavonoids on mutant H-Rasp protein

Mutant form of H-Ras (Harvey-Ras) proteins are found in almost 10%-25% of human tumours. Mutational activation transforms it into an oncogenic form, which results in the loss of intrinsic GTPase function and therefore the protein is constitutively in the active, GTP-bound state and is continuously sending signals for cell growth and proliferation. In the present insilico study, the inhibitory effect of different flavonoid compounds on mutant H Ras protein p21 has been assessed. In addition, inhibitory effect of flavonoids is compared with 3 known anticancer drugs. Upon docking, it was found that flavonoids such as Naringenin, Daidzein, and Hesperetin showed highest affinity (most negative ΔG), while Rutin showed no affinity towards mutant H Ras. The 3 clinical anticancer agents (Erlotinib, Letrozole and Exemestane) showed binding energies in the range of -1.11 to -5.51 kcal/mol which is comparatively lower than the flavonoids indicating efficacy of flavonoids in the treatment of cancer with little or no cytotoxicity. Our study demonstrates that flavonoids (particularly Naringenin, Daidzein, and Hesperetin) are the effective drugs to inhibit function of mutant H-Ras P21 protein, which in turn arrests the process of cell growth and proliferation of the cancer cell.     

Chromium Chloride Administration Causes a Substantial Reduction of Coronary Lipid Deposits,Aortic Lipid Deposits,and Serum Cholesterol Concentration in Rabbits

This experiment was carried out to test the null hypothesis that intramuscular trivalent chromium administration would not remove lipids from the heart and ascending aorta of the hyoercholesterolemic rabbits and would not lower their serum cholesterol levels. A novel computer-based method, previously described, was used to assess the sizes of the intracardiac and aortic lesions. Clinical chemistry and histopathology were performed through routine methods. The sizes of the lipid deposits in the coronary vasculature of the hypercholesterolemic rabbits were greatly reduced as a result of the intramuscular chromium chloride injections. Lipid deposits in the ascending aorta were similarly reduced, as well as the serum cholesterol concentrations. The terminal serum chromium concentrations in the chromium-treated group were in the range of 3,258–4,513 μg/L, whereas, in the untreated animals, the concentrations were 3.2 to 6.3 μg/L. The general condition of the chromium-treated animals was good and they were continuing to gain weight up to the time they were killed. However, it was found that their liver function tests had become abnormal even though there was no evidence of hepatic histopathological lesions specifically affecting the chromium-treated group. The kidney function tests and histopathology were normal. These findings suggest that a more aggressive approach than those tried hitherto might be useful in treating atherosclerotic human patients with chromium.