Project description:We investigated a contaminant-degrading microbial community by sequencing total RNA (without rRNA depletion) from microcosms containing sediment from a hypoxic contaminated aquifer fed with isotopically labeled toluene.
Project description:Glyphosate is known to inhibit 5-enolpyruvylshikimate-3-phosphate synthase of the chorismate biosynthetic pathway, and chorismate is a precursor to aromatic amino acids, auxin, and many other secondary products. Although the perennial weed leafy spurge (Euphorbia esula L.) is considered glyphosate tolerant, glyphosate is often used as part of an integrated pest management program in non-cultivated ecosystems of North America. Part of its tolerance is attributed to escape through an abundance of underground adventitious buds (UABs). Sub-lethal concentrations of foliar applied glyphosate leads to new shoot growth from UABs that have a stunted and/or bushy phenotype after growth-inducing decapitation. To gain insights into glyphosateM-bM-^@M-^Ys impact on molecular mechanisms associated with the stunted and bushy phenotype, we obtained global transcriptome abundance using RNAseq from a subsequent generation of aerial shoots derived from crown buds of glyphosate-treated and -untreated leafy spurge. We further correlated transcript abundance to accumulation of shikimate and phytohormones from the same samples to elucidate interactions. Abundance of shikimate was similar in subsequent generations of aerial shoots generated from crown buds of treated and untreated plants and is likely not a direct factor leading to the stunted and bushy phenotype. However, the results do suggest that transcripts involved in auxin transport and signaling and crosstalk with other phytohormones likely play a role in the bushy phenotype. The results of this study provide some insights for identifying new targets for manipulation of plant growth and development. Transcriptome and metabolite profiling are obtained for aerial tissues derived from crown buds of foliar glyphosate-treated and control (2.24 or 0 kg/ha active ingredient glyphosate + 0.25% v/v surfactant) leafy spurge plants. Each experiment included 4 biological replicates.
Project description:Glyphosate is one of the most widely used herbicides globally. It acts by inhibiting an enzyme in an aromatic amino synthesis pathway specific to plants and microbes, leading to view that glyphosate poses no risk to other organisms. However, there is growing concern that glyphosate is associated with detrimental health effects in humans, and an ever-increasing body of evidence suggests that glyphosate affects other animals including pollinating insects such as bees. Although pesticides have long been considered a contributing factor in the decline of wild bee populations most research on bees has focussed on demonstrating and understanding the effects (particularly sublethal ones) of insecticides. To assess whether glyphosate poses a potential risk to bees we characterised the changes in survival, behaviour, digestive tract proteome and microbiome in the bumblebee Bombus terrestris after chronic exposure to field relevant doses of glyphosate alone and as part of the commercially available product RoundUp Optima+®. Regardless of source, changes in response to herbicide exposure in important cellular and physiological processes in the digestive tract of B. terrestris were observed, with the abundances of proteins associated with oxidative stress regulation, metabolism, cellular adhesion, the extracellular matrix, and various signalling pathways being altered. Interestingly, endocytosis, oxidative phosphorylation, the TCA cycle, and carbohydrate, lipid, and amino acid metabolism were differentially altered depending on whether the exposure source was glyphosate AI or RoundUp Optima+®. In addition, RoundUp Optima+®, but not the active ingredient glyphosate, impacted fungal diversity in the digestive tract microbiota. Our research provides new insights into the potential mode of action and consequences of glyphosate exposure at the molecular and cellular levels in bumblebees and highlights issues with current regulatory measures involving commercial formulations of pesticides where the impact of the co-formulants on non-target organisms are generally overlooked.
Project description:Plants and rhizosphere microbes rely closely on each other, with plants supplying carbon to bacteria in root exudates, and bacteria mobilizing soil-bound phosphate for plant nutrition. When the phosphate supply becomes limiting for plant growth, the composition of root exudation changes, affecting rhizosphere microbial communities and microbially-mediated nutrient fluxes. To evaluate how plant phosphate deprivation affects rhizosphere bacteria, Lolium perenne seedlings were root-inoculated with Pseudomonas aeruginosa 7NR, and grown in axenic microcosms under different phosphate regimes (330 uM vs 3-6 uM phosphate). The effect of biological nutrient limitation was examined by DNA microarray studies of rhizobacterial gene expression.
Project description:Background: Glyphosate has become the most widely used herbicide in the world. Therefore, the development of new glyphosate-tolerant varieties is a research focus of seed companies and researchers. The glyphosate stress-responsive genes were used for the development of genetically modified crops, while only the EPSPS gene has been used currently in the study on glyphosate-tolerance in rice. Therefore, it is essential and crucial to intensify the exploration of glyphosate stress-responsive genes, to not only acquire otherglyphosate stress-responsive genes with clean intellectual property rights but also obtain non-transgenic glyphosate-tolerant rice varieties. This study is expected to elucidate the responses of miRNAs, lncRNAs, and mRNAs to glyphosate applications and the potential regulatory mechanisms in response to glyphosate stress in rice. Results: Leaves of the non-transgenic glyphosate-tolerant germplasm CA21 sprayed with 2 mg•ml-1 glyphosate (GLY) and CA21 plants with no spray (CK) were collected for high-throughput sequencing analysis. A total of 1197 DEGs, 131 DELs, and 52 DEMs were identified in the GLY samples in relation to CK samples. Genes were significantly enriched for various biological processes involved in detoxification of plant response to stress. A total of 385 known miRNAs from 59 miRNA families and 94 novel miRNAs were identified. Degradome analysis led to the identification of 32 target genes, of which, the squamosa promoter-binding-like protein 12 (SPL12) was identified as a target of osa-miR156a_L+1. The lncRNA-miRNA-mRNA regulatory network consisted of osa-miR156a_L+1, two transcripts of SPL12 (LOC_Os06g49010.3 and LOC_Os06g49010.5), and 13 lncRNAs (e.g., MSTRG.244.1 and MSTRG.16577.1). Conclusion: Large-scale expression changes in coding and noncoding RNA were observed in rice mainly due to its response to glyphosate. SPL12, osa-miR156, and lncRNAs (e.g., MSTRG.244.1 and MSTRG.16577.1) could be a novel ceRNA mechanism in response to glyphosate stress in rice.
Project description:Festuca species, Falcon was grown in greenhouse in two replications for control and different dose applications of glyphosate. Plants were sprayed with two different rates (5% and 20%) of isopropylamine salt of glyphosate at three leaf stage. Affymetrix Wheat Genome array was used for transcriptional profiling.
Project description:<br>Three Festuca species were grown in greenhouse in two replications for control and different dose applications of glyphosate. Plants were sprayed with two different rates (5% and 20%) of isopropylamine salt of glyphosate at three leaf stage. Affymetrix Wheat Genome array was used for transcriptional profiling.<br>