Foliar Application of Seaweed Sap Enhances Growth,Yield and Quality of Maize in Eastern Himalayas

Maize (Zea mays L.) productivity in hilly regions of North Eastern Region (NER) of India is very low due to limited use of manures and fertilizers. Under such situation, seaweed sap can become an alternative as it is an organic bio-stimulant. Experiment with extracts from marine algae Kappaphycus alvarezii (K sap) and Gracilaria edulis (G sap) was conducted during 2012 and 2013 to assess the efficacy of seaweed saps on growth, productivity and quality of maize and their role in economizing the chemical fertilizer requirement. Results revealed that K or G sap @ 10% and above concentrations along with 100% recommended dose of fertilizer (RDF) recorded significantly higher plant height, dry matter, chlorophyll content, yield attributes and yield of maize compared to control (water spray). The nitrogen (N) and protein content in grain was the highest under 15% K sap + 100% RDF followed by 15% G sap + 100% RDF. Application of K or G sap at 10% concentrations + 100% RDF also significantly increased micronutrient (copper, zinc, manganese and iron) concentrations in maize grains. The available nitrogen, phosphorous and potassium content in soil was recorded to be lowest under 7.5% K sap + 50% RDF. Thus, foliar application of 10% K or G sap along with 100% RDF is recommended for sustainable maize production in NER of India and other ecosystems elsewhere.

     

CD95-related apoptotic machinery is functional in pancreatic cancer cells

The CD95 (FAS, Apo-1) system is a major death pathway in normal and tumor cells. Recent evidence indicates that pancreatic cancer cells express CD95R and CD95L but are insensitive to CD95-mediated apoptosis. Here we show that treatment of human pancreatic cancer cells with RNA synthesis inhibitor actinomycin D (ActD) converted the phenotype of cancer cells from CD95 resistant to CD95 sensitive. Flow cytometric analysis demonstrated that all pancreatic cancer cell lines studied responded with cell surface CD95R and CD95L upregulation to bleomycin treatment, and PANC1 (mt p53) cells demonstrated a dose-dependent response to interferon gamma and bleomycin treatment with CD95R and CD95L up-regulation. However, only bleomycin sensitized PANC1 cells to CD95-mediated apoptosis. Taxol sensitized PANC1 and HPAC cells to CD95-mediated apoptosis without surface up-regulation of CD95R. These data suggest that pancreatic cancer cells possess a p53-independent mechanism of CD95R and CD95L surface upregulation and that surface expression of CD95R is not predictive of apoptotic function. Protein extracts of HPAC and PANC1 cells treated for 24 hours with a combination of ActD/agonist anti-CD95 antibodies demonstrated significantly higher Acetyl-Asp-Glu-Val-Asp-ase (DEVDase) cleavage activity (caspase 3-like activity) than extracts from cells treated with ActD only. In the present study, we also investigated the time kinetics of DEVDase (caspase 3-like) activation in PANC1 (mt p53) and HPAC (wt p53) pancreatic cancer cell lines. We found that DEVDase activity in PANC1 cells responds to ActD and ActD/anti-CD95 antibodies earlier than in HPAC cells; however, at 24 hours HPAC cells demonstrated much stronger activation. Cytosolic protein extracts from untreated cells did not influence caspase 3-like activity when added to extracts from the ActD/anti-CD95 antibody-treated cells. Collectively, these data suggest that pancreatic cancer cells have functional CD95-related apoptotic machinery with preserved apoptotic signal transduction, CD95R upregulation. and caspase activation. However, this system is blocked by some unknown protein(s) that is either located in the organelle fraction of the cell and/or requires an intact cell for manifestation of its activity.     

Identification of the messenger RNAs coding for the gag and env gene products of the murine mammary tumor virus

Full-length (35S) genomic RNA from murine mammary tumor virus (MuMTV) was translated in vitro, using a reticulocyte lysate system, into proteins of 105,000, 75,000, 65,000, 35,000, and 27,000 daltons. These proteins were all immunoprecipitable with a monospecific antiserum to the major viral core protein, p27, but not with antiserum to the major viral envelope glycoprotein, gp47. Translation in vitro of RNA of about 24S size extracted from MuMTV yielded proteins similar in size and immunoreactivity to the products of the 35S RNA translation. Polyadenylylated RNA isolated from an MuMTV-producing cell line was fractionated according to size by velocity sedimentation and subsequently hybridized to MuMTV complementary DNA probes. These studies identified at least three size classes (35S, 24S, and 14-18S) of intracellular MuMTV-specific RNA. The 35S intracellular RNA was translated into MuMTV-specific proteins identical in size and immunoreactivity to the products of the virion-derived 35S RNA. On the other hand, translation of the intracellular 24S RNA fraction resulted in the synthesis of proteins, of which two (of about 70,000 daltons) could be immunoprecipitated with anti-gp47 serum, but not with anti-p27 serum. From these data we conclude that MuMTV core and envelope proteins are synthesized from two different mRNAs with approximate sizes of 35S and 24S, respectively. Our results also imply that the intracellular 24S mRNA is synthesized by a process more complex than simple cleavage of the 35S RNA.     

Identification of the gene for an Escherichia coli poly(A) polymerase.

Many bacterial mRNAs, like those of eukaryotes, carry a polyadenylate sequence at their 3' termini, but neither the function of the bacterial poly(A) moieties nor their biosynthesis have been elucidated. To develop a genetic tool to approach the problem of bacterial poly(A) RNA, we have sought to identify the genes responsible for mRNA polyadenylylation. A poly(A) polymerase was purified to homogeneity from extracts of Escherichia coli and subjected to N-terminal sequence analysis. The 25-residue amino acid sequence obtained was used to design primers for the amplification of the corresponding coding region by the PCR from an E. coli DNA template. A 74-base-pair DNA segment was obtained that matched a region in the pcnB locus of E. coli, a gene that had originally been identified as controlling plasmid copy number [J. Lopilato, S. Bortner & J. Beckwith (1986) Mol. Gen. Genet. 205, 285-290] and was subsequently cloned and sequenced [J. Liu & J. S. Parkinson (1989) J. Bacteriol. 171, 1254-1261]. Direct evidence that the pcnB locus encodes poly(A) polymerase was provided by the observation that a bacterial strain transformed with an inducible expression vector carrying pcnB as a translational fusion produced 100-fold elevated levels of poly(A) polymerase upon induction. No increased poly(A) polymerase activity was observed in cells transformed with expression vectors carrying truncated forms of the pcnB gene. The identification of a gene encoding bacterial poly(A) polymerase opens the way for the study of the biosynthesis and function of bacterial polyadenylylated mRNA.     

Expression of the human erythrocyte glucose transporter in Escherichia coli.

The gene encoding the human erythrocyte glucose transporter, cloned from HepG2 hepatoma cells, was expressed in Escherichia coli by introducing a prokaryote-type ribosome binding site, subcloning the gene into the T7 promoter/T7 polymerase expression system, and transforming a strain that is defective in glucose transport. Cells bearing plasmids with the transporter gene take up 2-deoxy-D-glucose and D-glucose, unlike cells bearing plasmids without the transporter gene. Moreover, 2-deoxy-D-glucose uptake is inhibited by unlabeled D-glucose, cytochalasin B, or mercuric chloride but not by L-glucose. The glucose transport protein is inserted into the membrane of E. coli, as evidenced by immunoblotting experiments with two site-directed polyclonal antibodies, one directed against the COOH terminus of the glucose transporter and the other directed against a synthetic peptide containing amino acid residues 225-238. As detected with both antibodies, the protein migrates with apparent molecular mass of 34 kDa in sodium dodecyl sulfate/12% polyacrylamide, a size similar to that of the unglycosylated glucose-transport protein synthesized in vitro.