Growth performance of Ceriops decandra propagules as infl uenced by plant growth regulator: A conservation eff ort

Vegetative propagation could be an important advantage and also envisioned to be the best alternative for planting stock production in the absence or lack of seeds. In Pichavaram, mangrove forest Tamil Nadu, the Ceriops decandra (Rhizophoraceae) is one of the most endangered species and IUCN also declared this species as near threatened. Propagation of C. decandra, by propagule cuttings, treated with plant growth regulators (PGRs) is feasible and it was possible to produce three saplings from one propagule. The effect of PGRs like indole butyric acid (IBA), naphthalene acetic acid (NAA), gibberellic acid (GA3 ) on propagule cuttings of C. decandra were studied and the results revealed that best growth performance was recorded when the cuttings were treated with GA3 2000 ppm. The combination of NAA and IBA increased the rooting and leaf formation. Among the treatments, GA3 enhanced the number of leaves and roots, shoot and root length, fresh and dry weight of roots increased to a larger extent. All the plants are transferred to field in the mangrove forest of Pichavaram, TamilNadu, India

Human RECQ1 helicase-driven DNA unwinding, annealing, and branch migration : insights from DNA complex structures

RecQ helicases are a widely conserved family of ATP-dependent motors with diverse roles in nearly every aspect of bacterial and eukaryotic genome maintenance. However, the physical mechanisms by which RecQ helicases recognize and process specific DNA replication and repair intermediates are largely unknown. Here, we solved crystal structures of the human RECQ1 helicase in complexes with tailed-duplex DNA and ssDNA. The structures map the interactions of the ssDNA tail and the branch point along the helicase and Zn-binding domains, which, together with reported structures of other helicases, define the catalytic stages of helicase action. We also identify a strand-separating pin, which (uniquely in RECQ1) is buttressed by the protein dimer interface. A duplex DNA-binding surface on the C-terminal domain is shown to play a role in DNA unwinding, strand annealing, and Holliday junction (HJ) branch migration. We have combined EM and analytical ultracentrifugation approaches to show that RECQ1 can form what appears to be a flat, homotetrameric complex and propose that RECQ1 tetramers are involved in HJ recognition. This tetrameric arrangement suggests a platform for coordinated activity at the advancing and receding duplexes of an HJ during branch migration

Identification of a potent herbal molecule for the treatment of breast cancer

<p>Abstract</p> <p>Background</p> <p>Breast cancer (BCa)-related mortality still remains the second leading cause of cancer-related deaths worldwide. Patients with BCa have increasingly shown resistance and high toxicity to current chemotherapeutic drugs for which identification of novel targeted therapies are required.</p> <p>Methods</p> <p>To determine the effect of PDBD on BCa cells, estrogen-receptor positive (ER⁺)-MCF-7 and estrogen-receptor negative (ER^-)-MDA 231 cells were treated with PDBD and the cell viability, apoptotic, cell cycle, Western blot and Promoter assays were performed.</p> <p>Results</p> <p>PDBD inhibits cell viability of ER⁺and ER^-BCa cells by inducing apoptosis without causing significant toxicity in normal breast epithelial cells. While dissecting the mechanism of action of PDBD on BCa, we found that PDBD inhibits Akt signaling and its downstream targets such as NF-κB activation, IAP proteins and Bcl-2 expression. On the other hand, activation of JNK/p38 MAPK-mediated pro-apoptotic signaling was observed in both ER⁺and ER^-BCa cells.</p> <p>Conclusion</p> <p>These findings suggest that PDBD may have wide therapeutic application in the treatment of BCa.</p

Chickpea

The narrow genetic base of cultivated chickpea warrants systematic collection, documentation and evaluation of chickpea germplasm and particularly wild Cicer species for effective and efficient use in chickpea breeding programmes. Limiting factors to crop production, possible solutions and ways to overcome them, importance of wild relatives and barriers to alien gene introgression and strategies to overcome them and traits for base broadening have been discussed. It has been clearly demonstrated that resistance to major biotic and abiotic stresses can be successfully introgressed from the primary gene pool comprising progenitor species. However, many desirable traits including high degree of resistance to multiple stresses that are present in the species belonging to secondary and tertiary gene pools can also be introgressed by using special techniques to overcome pre- and post-fertilization barriers. Besides resistance to various biotic and abiotic stresses, the yield QTLs have also been introgressed from wild Cicer species to cultivated varieties. Status and importance of molecular markers, genome mapping and genomic tools for chickpea improvement are elaborated. Because of major genes for various biotic and abiotic stresses, the transfer of agronomically important traits into elite cultivars has been made easy and practical through marker-assisted selection and marker-assisted backcross. The usefulness of molecular markers such as SSR and SNP for the construction of high-density genetic maps of chickpea and for the identification of genes/QTLs for stress resistance, quality and yield contributing traits has also been discussed

Effect of vesicular arbuscular mycorrhizal fungus on the physiological and biochemical changes of five different tree seedlings grown under nursery conditions

The symbiotic association between certain plants and microorganisms plays an important role in soil fertilization, and improves their growth and mineral nutrition. The symbiotic association betweenvesicular arbuscular mycorrhizal (VAM) fungi and roots provides a significant contribution to plant nutrition and growth. VAM mycelium in soil results in greater efficiency of nutrient absorption particularly for slowly diffusing mineral ions, especially phosphorous. The present investigation aims at studying the effects of VAM fungi on the physiological changes of the selected tree seedlings viz.,Cassia siamea, Delonix regia, Erythrina variegata, Samanea saman and Sterculia foetida. The chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, protein, nitrate, nitrogen, phosphorus andpotassium content increased in VAM fungus treated seedlings compared with non-mycorrhizal tree seedlings. The total soluble sugars and soluble starch contents in the leaves of all the selected treespecies in the present study showed a decrease in mycorrhizal seedlings than non-mycorrhizal seedlings

BIOLOGICAL CONTROL OF RICE DISEASE (BLAST) BY USING TRICHODERMA VIRIDE IN LABORATORY CONDITIONS

The most common biological control agents of the genus Trichoderma have been reported as strains of T. virens, T. harzianum, and T. viride. Since Trichoderma biological control agent use different mechanisms of biocontrol, it is important to explore the synergistic effects expressed by different genotypes for their practical use in agriculture (Hemosa et al., 2000). Trichoderma species have been investigated as biological control agents for over 70 years, but it is only recently that strains have become commercially available. This finding is largely a result of the change in public attitude towards the use of chemical pesticides and fumigants such as methyl bromide. Trichoderma viride is an efficient biocontrol agent that is commercially produced to prevent development of several soil pathogenic fungi. Different mechanisms have been suggested as being responsible for their biocontrol activity, which includes competition for space and nutrients, secretion of chitinolytic enzymes, mycoparasitism and production of inhibitory compounds (Harman et al., 1993). Rice disease blast is caused by Pyricularia oryzae. Blast disease initial symptoms are white to gray-green lesions or spots with darkened borders produced on all parts of shoot; older lesions are elliptical or spindle-shaped and whitish gray with necrotic borders. Lesions are wide in the centre and pointed toward either end; lesions may enlarge and coalesce to kill entire leaves. The objective of this study is to control blast disease in rice. The study is to be conducted in the Faculty of Agriculture and Forestry, University of Guyana, at Berbice Campus, Science Centre, John, from February 2009 to May 2009. The experiments are designed in a completely random block design with three replicates. Parameters to be observed are selection of medium, temperature, pH, and measurement of disease index and disease severity randomly. The studies are to show the potential of T. viride for control of blast disease in rice