Agrobacterium-mediated transformation of alfalfa (Medicago sativa) using a synthetic cry3a gene to enhance resistance against alfalfa weevil

To introduce genetic resistance against alfalfa weevil (Hypera postica), leaves and petiole explants of three commercial alfalfa genotypes, including Km-27, Kk-14 and Syn-18 were transformed with Agrobacterium tumefaciens strains GV101, LBA4404 and AGL01. All the Agrobacterium strains used harbored the recombinant binary vector pBI121 containing a synthetic cry3a gene under the control of CaMV35S promoter as well as the nptII gene as selectable marker. Transformed explants were cultured on callus-induction medium, and the germinated somatic embryos were then transferred to the regeneration medium. The primary transformants were evaluated by PCR and Southern blot analysis. The results indicated successful integration of the target gene into the genomes of primary transgenic lines. Moreover, the expression of Cry3a protein in the transgenic plants was confirmed by ELISA method. Three transgenic lines, including TL6, TL8 and TL11 showed significantly higher levels of insect resistance against H. postica larvae (mortality rate of 73–90 % after infestation), in comparison with the control plants during the two-year bioassays. All transgenic plants were fertile and no irregular behavior in terms of growth and the morphological traits were observed. Transgenic plants developed during the course of this study are currently being grown in greenhouse and will be crossed with each other for seed production.     

Extracellular Signal-Regulated Kinase Regulates RhoA Activation and Tumor Cell Plasticity by Inhibiting Guanine Exchange Factor H1 Activity

In certain Ras mutant cell lines, the inhibition of extracellular signal-regulated kinase (ERK) signaling increases RhoA activity and inhibits cell motility, which was attributed to a decrease in Fra-1 levels. Here we report a Fra-1-independent augmentation of RhoA signaling during short-term inhibition of ERK signaling. Using mass spectrometry-based proteomics, we identified guanine exchange factor H1 (GEF-H1) as mediating this effect. ERK binds to the Rho exchange factor GEF-H1 and phosphorylates it on S959, causing inhibition of GEF-H1 activity and a consequent decrease in RhoA activity. Knockdown experiments and expression of a nonphosphorylatable S959A GEF-H1 mutant showed that this site is crucial in regulating cell motility and invasiveness. Thus, we identified GEF-H1 as a critical ERK effector that regulates motility, cell morphology, and invasiveness.     

Physiological,biochemical, and metabolic responses of a Taxus baccata L. callus culture under drought stress

In Vitro Cellular & Developmental Biology - Plant - The metabolic stimulation induced by abiotic stress is an efficient strategy for the production of secondary metabolites in sterile and...     

Design,Synthesis and Enzymatic Inhibition of Novel Unusual Amino Acids as a Transition State Analogue of Amyloid Precursor Protein Peptide

International Journal of Peptide Research and Therapeutics - β-secretase 1 (BACE1) plays a pivotal role in the pathology of Alzheimer?s disease via accumulation beta amyloid in the...     

A comparison between osteogenic differentiation of human unrestricted somatic stem cells and mesenchymal stem cells from bone marrow and adipose tissue

To evaluate the potential of three stem cells for cell therapy and tissue engineering applications, the biological behavior and osteogenic capacity of the newly introduced cord-blood-derived, unrestricted somatic stem cells (USSC) were compared with those of mesenchymal stem cells isolated from bone marrow (BM-MSC) and adipose tissue (AT-MSC). There was no significant difference between the rates of proliferation of the three stem cells. During osteogenic differentiation, alkaline phosphatase (ALP) activity peaked on day 7 in USSC compared to BM-MSC which showed the maximum value of ALP activity on day 14. However, BM-MSC had the highest ALP activity and mineralization during osteogenic induction. In addition, AT-MSC showed the lowest capacity for mineralization during differentiation and had the lowest ALP activity on days 7 and 14. Although AT-MSC expressed higher levels of collagen type I, osteonectin and BMP-2 in undifferentiated state, but these genes were expressed higher in BM-MSC during differentiation. BM-MSC also expressed higher levels of ALP, osteocalcin and Runx2 during induction. Taking together, BM-MSC showed the highest capacity for osteogenic differentiation and hold promising potential for bone tissue engineering and cell therapy applications.     

Analysis of microRNA signatures using size-coded ligation-mediated PCR

The expression pattern and regulatory functions of microRNAs (miRNAs) are intensively investigated in various tissues, cell types and disorders. Differential miRNA expression signatures have been revealed in healthy and unhealthy tissues using high-throughput profiling methods. For further analyses of miRNA signatures in biological samples, we describe here a simple and efficient method to detect multiple miRNAs simultaneously in total RNA. The size-coded ligation-mediated polymerase chain reaction (SL-PCR) method is based on size-coded DNA probe hybridization in solution, followed-by ligation, PCR amplification and gel fractionation. The new method shows quantitative and specific detection of miRNAs. We profiled miRNAs of the let-7 family in a number of organisms, tissues and cell types and the results correspond with their incidence in the genome and reported expression levels. Finally, SL-PCR detected let-7 expression changes in human embryonic stem cells as they differentiate to neuron and also in young and aged mice brain and bone marrow. We conclude that the method can efficiently reveal miRNA signatures in a range of biological samples.     

Effects of Co-Inoculation with Arbuscular Mycorrhizal Fungi and Rhizobia on Fungal Occupancy in Chickpea Root and Nodule Determined by Real-Time PCR

Legume roots in nature are usually colonized with rhizobia and different arbuscular mycorrhizal fungi (AMF) species. Light microscopy that visualizes the presence of AMF in roots is not able to differentiate the ratio of each AMF species in the root and nodule tissues in mixed fungal inoculation. The purpose of this study was to characterize the dominant species of mycorrhiza in roots and nodules of plants co-inoculated with mycorrhizal fungi and rhizobial strains. Glomus intraradices (GI), Glomus mosseae (GM), their mix (GI + GM), and six Mesorhizobium ciceri strains were used to inoculate chickpea. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess occupancy of these fungal species in roots and nodules. Results showed that GI molecular ratio and relative density were higher than GM in both roots and nodules. These differences in molecular ratio and density between GI and GM in nodules were three folds higher than roots. The results suggested that M. ciceri strains have different effects on nodulation and mycorrhizal colonization pattern. Plants with bacterial S3 and S1 strains produced the highest root nodulation and higher fungal density in both the roots and nodules.     

ANTIMICROBIAL AND ANTIHYPERLIPIDEMIC ACTIVITIES OF ISOLATED QUERCETIN FROM ANABAENA AEQUALIS1

This study aimed to isolate quercetin (for the first time) from Anabaena aequalis Borge, which inhabits soil surface of Wadi El‐Alaqui Protectorate located in Aswan city, Egypt. The isolated compound showed significant antibacterial activity against the gram‐positive bacteria Sarcina maxima and Micrococcus kristinae, the gram‐negative bacterium Klebsiella pneumoniae, as well as against the filamentous fungus Aspergillus flavus. The isolated compound was identified as quercetin using the structure elucidation based on UV, electrospray ionization mass spectrometry (ESIMS), ¹H and ¹³C NMR, proton–proton correlation spectroscopy (¹H‐¹H COSY), distortionless enhancement by polarization transfer (DEPT), heteronuclear single quantum coherence (HSQC), and heteronuclear multiple bond correlations spectrum (HMBC). Medium lethal dose (LD₅₀) of the isolated compound and its side effects against hyperlipidemia induced by ethanol intake in albino rats were carried out. No deaths were reported in rats within 72 h, which suggests that the isolated compound plays a beneficial role as an antihyperlipidemic agent in the treatment of alcohol‐induced hepatic tissue damage, which can be described as one of the therapeutic values.     

Role of Zooplankton Diversity in Vibrio cholerae Population Dynamics and in the Incidence of Cholera in the Bangladesh Sundarbans

Vibrio cholerae, a bacterium autochthonous to the aquatic environment, is the causative agent of cholera, a severe watery, life-threatening diarrheal disease occurring predominantly in developing countries. V. cholerae, including both serogroups O1 and O139, is found in association with crustacean zooplankton, mainly copepods, and notably in ponds, rivers, and estuarine systems globally. The incidence of cholera and occurrence of pathogenic V. cholerae strains with zooplankton were studied in two areas of Bangladesh: Bakerganj and Mathbaria. Chitinous zooplankton communities of several bodies of water were analyzed in order to understand the interaction of the zooplankton population composition with the population dynamics of pathogenic V. cholerae and incidence of cholera. Two dominant zooplankton groups were found to be consistently associated with detection of V. cholerae and/or occurrence of cholera cases, namely, rotifers and cladocerans, in addition to copepods. Local differences indicate there are subtle ecological factors that can influence interactions between V. cholerae, its plankton hosts, and the incidence of cholera.