Search

A regulated stress response is essential for healthy child growth and development trajectories. We conducted a cluster-randomized trial in rural Bangladesh (funded by the Bill & Melinda Gates Foundation, ClinicalTrials.gov NCT01590095) to assess the effects of an integrated nutritional, water, sanitation, and handwashing intervention on child health. We previously reported on the primary outcomes of the trial, linear growth and caregiver-reported diarrhea. Here, we assessed additional prespecified outcomes: physiological stress response, oxidative stress, and DNA methylation (N = 759, ages 1–2 years). Eight neighboring pregnant women were grouped into a study cluster. Eight geographically adjacent clusters were block-randomized into the control or the combined nutrition, water, sanitation, and handwashing (N + WSH) intervention group (receiving nutritional counseling and lipid-based nutrient supplements, chlorinated drinking water, upgraded sanitation, and handwashing with soap). Participants and data collectors were not masked, but analyses were masked. There were 358 children (68 clusters) in the control group and 401 children (63 clusters) in the intervention group. We measured four F2-isoprostanes isomers (iPF(2α)-III; 2,3-dinor-iPF(2α)-III; iPF(2α)-VI; 8,12-iso-iPF(2α)-VI), salivary alpha-amylase and cortisol, and methylation of the glucocorticoid receptor (NR3C1) exon 1F promoter including the NGFI-A binding site. Compared with control, the N + WSH group had lower concentrations of F2-isoprostanes isomers (differences ranging from −0.16 to −0.19 log ng/mg of creatinine, P < 0.01), elevated post-stressor cortisol (0.24 log µg/dl; P < 0.01), higher cortisol residualized gain scores (0.06 µg/dl; P = 0.023), and decreased methylation of the NGFI-A binding site (−0.04; P = 0.037). The N + WSH intervention enhanced adaptive responses of the physiological stress system in early childhood. A regulated stress response is essential for healthy child growth and development. Here, the authors show that a nutrition, water, sanitation, and hygiene intervention enhanced adaptive responses of the physiological stress system in early childhood. [ABSTRACT FROM AUTHOR]

Dormancy in underground vegetative buds of Canada thistle, an herbaceous perennial weed, allows escape from current control methods and contributes to its invasive nature. In this study, ∼65 % of root sections obtained from greenhouse propagated Canada thistle produced new vegetative shoots by 14 days post-sectioning. RNA samples obtained from sectioned roots incubated 0, 24, 48, and 72 h at 25°C under 16:8 h light-dark conditions were used to construct four MID-tagged cDNA libraries. Analysis of in silico data obtained using Roche 454 GS-FLX pyrosequencing technologies identified molecular networks associated with paradormancy release in underground vegetative buds of Canada thistle. Sequencing of two replicate plates produced ∼2.5 million ESTs with an average read length of 362 bases. These ESTs assembled into 67358 unique sequences (21777 contigs and 45581 singlets) and annotation against the Arabidopsis database identified 15232 unigenes. Among the 15232 unigenes, we identified processes enriched with transcripts involved in plant hormone signaling networks. To follow-up on these results, we examined hormone profiles in roots, which identified changes in abscisic acid (ABA) and ABA metabolites, auxins, and cytokinins post-sectioning. Transcriptome and hormone profiling data suggest that interaction between auxin- and ABA-signaling regulate paradormancy maintenance and release in underground adventitious buds of Canada thistle. Our proposed model shows that sectioning-induced changes in polar auxin transport alters ABA metabolism and signaling, which further impacts gibberellic acid signaling involving interactions between ABA and FUSCA3. Here we report that reduced auxin and ABA-signaling, in conjunction with increased cytokinin biosynthesis post-sectioning supports a model where interactions among hormones drives molecular networks leading to cell division, differentiation, and vegetative outgrowth. [ABSTRACT FROM AUTHOR]

Thellungiella parvula is related to Arabidopsis thaliana and is endemic to saline, resource-poor habitats, making it a model for the evolution of plant adaptation to extreme environments. Here we present the draft genome for this extremophile species. Exclusively by next generation sequencing, we obtained the de novo assembled genome in 1,496 gap-free contigs, closely approximating the estimated genome size of 140 Mb. We anchored these contigs to seven pseudo chromosomes without the use of maps. We show that short reads can be assembled to a near-complete chromosome level for a eukaryotic species lacking prior genetic information. The sequence identifies a number of tandem duplications that, by the nature of the duplicated genes, suggest a possible basis for T. parvula's extremophile lifestyle. Our results provide essential background for developing genomically influenced testable hypotheses for the evolution of environmental stress tolerance. [ABSTRACT FROM AUTHOR]

Annotation of the genome sequence of Arabidopsis thaliana has identified a diverse array of 245 full-length cytochrome P450 monooxygenase (P450) genes whose known functions span the synthetic gamut from critical structural components (phenylpropanoids, fatty acids, sterols) to signaling molecules (oxylipins, brassinosteroids, abscisic acid, gibberellic acid) and defense compounds (alkaloids, terpenes, coumarins). Numerous others in this collection mediate functions that are now being addressed using microarray and oligoarray technologies, molecular modeling, heterologous expression and insertional mutageneses. Profilings of their constitutive and inducible transcript levels have begun to cluster P450s that are likely to mediate tissue-specific and stress-specific monooxygenations. With proper appreciation of the high identities that exist among some of the most recently duplicated P450 sequences, these studies have begun to differentiate P450s with early response functions leading to production of stress signaling molecules and late response functions leading to the synthesis of protective compounds. Further functional analyses of these P450 sequences with perspectives on their response profiles rely on a variety of theoretical modeling and experimental approaches that can ultimately be tied to the transcriptional profiles and genetic mutants. This review surveys historical and evolutionary aspects of P450 studies, expression variations among Arabidopsis P450 loci, catalytic site regions critical for substrate recognition and, finally, genetic mutations/disruptions that can ultimately tie biochemical reactions to physiological functions in a manner not yet possible in most other organisms. [ABSTRACT FROM AUTHOR]

Gene sequences encoding gibberellin (GA) biosynthetic and catabolic enzymes were isolated from ‘Himalaya’ barley. These genes account for most of the enzymes required for the core pathway of GA biosynthesis as well as for the first major catabolic enzyme. By means of DNA gel blot analysis, we mapped coding sequences to chromosome arms in barley and wheat using barley-wheat chromosome addition lines, nulli-tetrasomic substitution and ditelosomic lines of wheat. These same sequences were used to identify closely related sequences from rice, which were mapped in silico, thereby allowing their syntenic relationship with map locations in barley and wheat to be investigated. Determination of the chromosome arm locations for GA metabolic genes provides a framework for future studies investigating possible identity between GA metabolic genes and dwarfing genes in barley and wheat. [ABSTRACT FROM AUTHOR]

The Me1 gene of the dicot Flaveria bidentis encodes NADP malic enzyme, which catalyses the decarboxylation reaction of C4 photosynthesis in bundle sheath cells. We have previously shown that the 3′ non-coding region ( Me1 3′) controls quantitative expression of the gene. We wondered whether Me1 3′ can increase expression when combined with heterologous promoters. We tested a highly expressed, constitutive promoter, the S4 promoter from subterranean clover stunt virus, and a highly expressed, leaf-specific promoter, the light-harvesting chlorophyll a/ b-binding protein gene 3 ( Lhcb3) promoter of Arabidopsis thaliana. Promoter-3′-end combinations were tested in transgenic C4 Flaveria plants and C3 tobacco. We found that Me1 3′ increased expression of the gusA reporter gene several-fold in leaves of both species in combination with either of the promoters. In both cases Me1 3′ does not alter the expression pattern for either promoter. We conclude that Me1 3′ can be used as a transcription terminator to increase transgene expression in C3 dicot plants. [ABSTRACT FROM AUTHOR]

The Me1 gene of Flaveria bidentis codes for the C4 isoform of NADP malic enzyme, which accumulates to a high-level only in bundle sheath cells. Previous experiments demonstrated that sequences at the 5′ end of the gene control cell specificity whereas sequences at the 3′ end are necessary for high-level expression. To localize quantitative regulator sequences, we have analysed a series of Me1 3′ deletion constructs fused to the gusA reporter gene. We show that sequences within the 3′-untranslated region (3′-UTR) control quantitative levels of expression. Analysis of 5′ promoter fusions demonstrated that high-level expression also requires sequences within the N-terminal coding region of the gene, suggesting possible interactions between the 3′-UTR and 5′ coding regions. Cell-specific regulatory sequences are located in a different part of the 5′ end of the gene, between 1023 bp upstream of the transcription start and the start of translation. [ABSTRACT FROM AUTHOR]

Abstract. A simple method for the normalisation of cDNA libraries is presented. The method has been used to normalise barley and wheat endosperm libraries. Gene probes for transcripts present at different frequencies in the primary library were used to evaluate the effectiveness of the normalisation process. [ABSTRACT FROM AUTHOR]