Rice straw application with different water regimes stimulate enzymes activity and improve aggregates and their organic carbon contents in a paddy soil.

Soil organic carbon plays considerable roles in binding soil particles together forming aggregates. Carbon (C) incorporated within these aggregates is thought to be microbially processed; thus, investigating changes in microbial activities i.e. dehydrogenase, urease, catalase and phosphatase enzymes may explain, to some extent, the dynamics and probably mechanisms responsible of formation of these aggregates. Since, soil water content (SWC) may take part in stimulating/lessening activities of organic matter decomposers; thus, this study aimed at investigating the effects of rice straw as a source of organic C in combination with variable SWC on bioaccumulation of C within different soil aggregate size fractions (2000-250, 250-53 and < 53 µm) and hence formation of these aggregates. To achieve these objectives, a pot experiment was conducted for 90 days, including five water levels i.e. maintaining a water head 1 cm above the soil surface (W1), 100% of the saturation percentage, SP (W2), 80% of SP (W3), 65% of SP (W4) and 50% of SP (W5), beside of two rates of applied rice straw i.e. 0 and 15 g kg-1 (w/w). Results revealed that application of rice straw at a rate of 15 g kg-1 increased the activities of dehydrogenase, urease, neutral phosphatase and catalase enzymes within the first 60 days after application; thereafter, activities of the first three enzymes decreased considerably. Likewise, formation of soil macro- (2000-250 µm) and micro-aggregates (250-53 µm) increased by the end of the experimental period. The highest concentrations of soil carbon were incorporated within soil macro-aggregate, whereas the least C content was found within the "silt + clay" fraction. Increasing SWC resulted in significant reductions in activities of the aforementioned enzymes and consequent reductions occurred in soil aggregation. Carbon content within aggregates sized <250 µm were significantly correlated with the percentage of these aggregates in soil. Thus, soil aggregation is thought to be the byproduct of an aerobic biosynthetic microbial process in which more stable hydrophobic organic C existed mainly in macropores. This process probably occurred within the first 60 days after RS application.

Tumor necrosis factor receptor superfamily 10B (TNFRSF10B): an insight from structure modeling to virtual screening for designing drug against head and neck cancer.

BACKGROUND: Head and neck cancer (HNC) belongs to a group of heterogeneous disease with distinct patterns of behavior and presentation. TNFRSF10B, a tumor suppressor gene mapped on chromosome 8. Mutation in candidate gene is responsible for the loss of chromosome p arm which is frequently observed in head and neck tumors. TNFRSF10B inhibits tumor formation through apoptosis but deregulation encourages metastasis, migration and invasion of tumor cell tissues. RESULTS: Structural modeling was performed by employing MODELLER (9v10). A suitable template [2ZB9] was retrieved from protein databank with query coverage and sequence identity of 84% and 30% respectively. Predicted Model evaluation form Rampage revealed 93.2% residues in favoured region, 5.7% in allowed region while only 1 residue is in outlier region. ERRAT and ProSA demonstrated 51.85% overall quality with a -1.08 Z-score of predicted model. Molecular Evolutionary Genetics Analysis (MEGA 5) tool was executed to infer an evolutionary history of TNFRSF10B candidate gene. Orthologs and paralogs [TNFRSF10A & TNFRSF10D] protein sequences of TNFRSF10B gene were retrieved for developed ancestral relationship. Topology of tree presenting TNFRSF10A gene considered as outgroup. Human and gorilla shared more than 90% similarities with conserved amino acid sequence. Virtual screening approach was appliedfor identification of novel inhibitors. Library (Mcule) was screened for novel inhibitors and utilized the scrutinized lead compounds for protein ligand docking. Screened lead compounds were further investigated for molecular docking studies. STRING server was employed to explore protein-protein interactions of TNFRSF10B target protein. TNFSF10 protein showed highest 0.999 confidence score and selected protein-protein docking by utilizing GRAMM-X server. In-silico docking results revealed I-58, S-90 and A-62 as most active interacting residues of TNFRSF10B receptor protein with R-130, S-156 and R-130 of TNFSF10B ligand protein. CONCLUSION: Current research may provide a backbone for understanding structural and functional insights of TNFRSF10B protein. The designed novel inhibitors and predicted interactions might serve to inhibit the disease. Effective in-vitro potent ligands are required which will be helpful in future to design a drug to against Head and neck cancer disease. There is an urgent need for affective drug designing of head and neck cancer and computational tools for examining candidate genes more efficiently and accurately are required.