A Polyadenylation Factor Subunit Implicated in Regulating Oxidative Signaling in Arabidopsis thaliana

BACKGROUND: Plants respond to many unfavorable environmental conditions via signaling mediated by altered levels of various reactive oxygen species (ROS). To gain additional insight into oxidative signaling responses, Arabidopsis mutants that exhibited tolerance to oxidative stress were isolated. We describe herein the isolation and characterization of one such mutant, oxt6. METHODOLOGY/PRINCIPAL FINDINGS: The oxt6 mutation is due to the disruption of a complex gene (At1g30460) that encodes the Arabidopsis ortholog of the 30-kD subunit of the cleavage and polyadenylation specificity factor (CPSF30) as well as a larger, related 65-kD protein. Expression of mRNAs encoding Arabidopsis CPSF30 alone was able to restore wild-type growth and stress susceptibility to the oxt6 mutant. Transcriptional profiling and single gene expression studies show elevated constitutive expression of a subset of genes that encode proteins containing thioredoxin- and glutaredoxin-related domains in the oxt6 mutant, suggesting that stress can be ameliorated by these gene classes. Bulk poly(A) tail length was not seemingly affected in the oxt6 mutant, but poly(A) site selection was different, indicating a subtle effect on polyadenylation in the mutant. CONCLUSIONS/SIGNIFICANCE: These results implicate the Arabidopsis CPSF30 protein in the posttranscriptional control of the responses of plants to stress, and in particular to the expression of a set of genes that suffices to confer tolerance to oxidative stress

Gene Expression Profiles of Colonic Mucosa in Healthy Young Adult and Senior Dogs

Background: We have previously reported the effects of age and diet on nutrient digestibility, intestinal morphology, and large intestinal fermentation patterns in healthy young adult and senior dogs. However, a genome-wide molecular analysis of colonic mucosa as a function of age and diet has not yet been performed in dogs. Methodology/Principal Findings: Colonic mucosa samples were collected from six senior (12-year old) and six young adult (1-year old) female beagles fed one of two diets (animal protein-based vs. plant protein-based) for 12 months. Total RNA in colonic mucosa was extracted and hybridized to Affymetrix GeneChipH Canine Genome Arrays. Results indicated that the majority of gene expression changes were due to age (212 genes) rather than diet (66 genes). In particular, the colonic mucosa of senior dogs had increased expression of genes associated with cell proliferation, inflammation, stress response, and cellular metabolism, whereas the expression of genes associated with apoptosis and defensive mechanisms were decreased in senior vs. young adult dogs. No consistent diet-induced alterations in gene expression existed in both age groups, with the effects of diet being more pronounced in senior dogs than in young adult dogs. Conclusion: Our results provide molecular insight pertaining to the aged canine colon and its predisposition to dysfunction and disease. Therefore, our data may aid in future research pertaining to age-associated gastrointestinal physiologica

A fast and quantitative assay for developing zeolite-type hydrocarbon trap catalyst

A fast parallel method for determining the amount of toluene adsorbed over a variety of zeolites has been established. A three-step approach, including parallel adsorption of toluene onto the catalyst samples, the destructive or non-destructive extraction of trapped toluene by solvents including n-octane and 2,2,4,-trimethyl pentane (TMP) with NaOH and HF, respectively, and optical assay based on the characteristic absorption of toluene (ca. 261 nm of UV), has been performed sequentially to give a fast parallel and quantitative evaluation of the amount of toluene trapped over promising zeolite-type hydrocarbon trap catalysts. The results correlate well with those obtained by means of traditional, time-consuming techniques such as temperature-programmed desorption (TPD). (c) 2006 Elsevier Inc. All rights reserved.X1124sciescopu

Role of cobalt on gamma-Al2O3 based NOx storage catalyst

Co/Pt/Ba/gamma-Al2O3, Co/Ba/gamma-Al2O3, Pt/Ba/gamma-Al2O3, Co/Pt/gamma-Al2O3, Ba/gamma-Al2O3, Pt/gamma-Al2O3, and Co/gamma-Al2O3 type catalysts were prepared by a conventional impregnation method, and their NOx storage capacities were evaluated by colorimetric assay. Co-containing catalysts had a higher NO (x) storage capacity than that of Co-free counterparts. The role of each component, especially Co, for the catalysts prepared was investigated by using in-situ FTIR. The high NOx storage for Co-containing catalysts including Co/Ba/gamma-Al2O3 and Co/Pt/Ba/gamma-Al2O3 is mainly due to the formation of Co3O4 on the catalyst surface identified by XAFS.X1112sciescopu

Promising zeolite-type hydrocarbon trap catalyst by a knowledge-based combinatorial approach

Libraries consisting of more than 100 zeolite samples were prepared and examined for developing a promising HC trap catalyst. Parallel adsorptions of toluene onto the catalyst samples were conducted over a 10 x 10 array reactor under dry and wet conditions with or without a heating process three knowledge-based conditions for developing an automotive catalyst during the cold-start period. FAU and BEA type zeolites revealed a high performance of toluene adsorption under the dry condition. However, FAU type zeolite significantly decreased the amount of toluene adsorbed in the presence of water in the feed gas stream, mainly due to the hydrophobicity of the catalyst surface. Over Beta type zeolites, the toluene adsorbed was found to be considerably preserved, even after forced desorption temperature-ramping to the warm-up condition of an automotive engine. Li, K, or Ag ion-exchanged Beta zeolites seem to be particularly promising as an HC trap catalyst. (C) 2008 Elsevier Inc. All rights reserved.X112122sciescopu

Colorimetric assay for a fast parallel screening of NOx storage

A fast parallel method for determining the capacity of an automotive catalyst to trap and especially store NOx has been established. A three-step approach, including parallel adsorption of NO onto the catalyst samples, water extraction of trapped NOx in the form of NO2- and NO3- in an aqueous solution, and colorimetric assay based on the sensitive and dramatic color change from colorless to deep red of the organic dye through the Griess diazotation reaction has been performed sequentially to give a fast parallel and quantitative evaluation of the amount of NOx trapped over promising automotive catalysts. The results correlate well with those obtained by means of traditional, time-consuming techniques, such as temperature-programmed desorption. (c) 2006 Elsevier Inc. All rights reserved.X115sciescopu