Project description:Earthworms enhance plant growth but the precise mechanism by which this occurs is not known. An understanding of the mechanism could potentially support changes in agricultural management reducing fertiliser usage and therefore costs and the carbon footprint of agriculture. We conducted a factorial experiment in which 5 strains of wheat were grown in the presence and absence of earthworms under regular watering and droughted conditions. The different wheat strains all responded in a similar fashion. Plant biomass was greater in the presence of earthworms and under regular watering. The presence of earthworms reduced the impact of drought on plant biomass and also slowed down the rate of drying of the droughted soils. Plant nutrient content (N, P, Si) showed no consistent pattern with treatments but total N, P and Si mirrored plant biomass and decreased in the order earthworm-present watered > earthworm-present droughted > earthworm-absent watered > earthworm-absent droughted. Nutrient availability in the soil, as assessed by chemical extractions showed no consistent pattern with treatments. Differential gene expression of plants was greater between watering treatments than between earthworm treatments. Genes that were differentially expressed between the earthworm treatments predominantly related to plant defences, abiotic stress and control of plant growth though a couple were linked to both nitrogen cycling and stress responses. The soil microbiome of the earthworm-present treatments was more associated with nutrient-rich environments, the promotion of plant growth and the suppression of plant pathogens. Our data suggest that enhanced plant growth was due to changes in the microbiome due to earthworm processing of the soil rather than changes in nutrient availability due to the presence of earthworms.
Project description:Single-cell mRNA sequencing (scRNA-seq) technologies are reshaping the current cell-type classification system. In previous studies, we built the mouse cell atlas (MCA) and human cell landscape (HCL) to catalog all cell types by collecting scRNA-seq data. However, systematically study for zebrafish (Danio rerio), fruit fly (Drosophila melanogaster) and earthworm (Eisenia andrei) are still lacking. Here, we construct the zebrafish, Drosophila and earthworm cell atlas with Microwell-seq protocols, which provides valuable resources for characterization of diverse cell populations of zebrafish, Drosophila and earthworm, and studying difference between vertebrates and Invertebrates at single cell level.
Project description:RNA-Seq is ubiquitous, but depending on the study, sub-optimal sample handling may be required, resulting in repeated freeze-thaw cycles. However, little is known about how each cycle impacts downstream analyses, due to a lack of study and known limitations in common RNA quality metrics, e.g., RIN, at quantifying RNA degradation following repeated freeze-thaws. Here we quantify the impact of repeated freeze-thaw on the reliability of downstream RNA-Seq analysis. To do so, we developed a method to estimate the relative noise between technical replicates independently of RIN. Using this approach we inferred the effect of both RIN and the number of freeze-thaw cycles on sample noise. We find that RIN is unable to fully account for the change in sample noise due to freeze-thaw cycles. Additionally, freeze-thaw is detrimental to sample quality and differential expression (DE) reproducibility, approaching zero after three cycles for poly(A)-enriched samples, wherein the inherent 3’ bias in read coverage is more exacerbated by freeze-thaw cycles, while ribosome-depleted samples are less affected by freeze-thaws. The use of poly(A)-enrichment for RNA sequencing is pervasive in library preparation of frozen tissue, and thus, it is important during experimental design and data analysis to consider the impact of repeated freeze-thaw cycles on reproducibility.
Project description:Purpose: Tag-based approach for global gene expression analysis has been revolutionised with the advent of next generation sequencing (NGS) technology. The aim of the present study is to present comprehensive view of differentially expressed genes under cold and freeze stress in seabuckthorn (Hippophae rhamnoides L.) Methods: DeepSAGE, a tag based approach, was used to identify differentially expressed genes under cold and freeze treatments in seabuckthorn (Hippophae rhamnoides L.). The 30 days old plantlets, at six leaves stage, were subjected to cold stress (CS) at 4°C and freeze stress (FS) at -10°C treatment for 6 hr. The seedlings grown at 28°C were taken as control (CON). Total RNA from all the three samples was isolated. Illumina Gene Expression Sample Prep Kit and Solexa Sequencing Chip (Flowcell) were used for tag preparation and the main instruments used for sequencing included Illumina Cluster Station and Illumina HiSeqTM 2000 System. Bioinformatics analysis resulted in to high number of differentially expressed genes under cold and freeze stress. Results: 36.2 million raw tags including 13.9 million distinct tags were generated from three leaf tissue libraries (control, cold stress and freeze stress). After removing low quality tags, 35.5 million clean tags including 7 million distinct clean tags were obtained. In total, 11922 differentially expressed genes (DEGs) were identified including 6539 up regulated and 5383 down regulated genes. Conclusions: DeepSAGE data of seabuckthorn provided useful resource and reference dataset for further functional genomics analysis in seabuckthorn and other important crops. The present study implicated a large number of genes with different biological functions expressing differentially in response to cold and freeze stress treatment. Isolation and further characterization of these genes will help researchers in understanding their role in cold and freeze tolerance in seabuckthorn and may provide important gene resources to be exploited for the development of stress tolerant crop plants in future.
Project description:Purpose: We studied the potential effects of lindane aging in soil on model earthworm Eisenia fetida at the transcriptomic level. Methods: transcriptomes of earthworms were generated by RNA sequencing using Illumina Hiseq Xten platform. Results: There were 1325 DE unigenes in G2 (1074 up and 251 down), 784 DE unigenes in G3 (457 up and 327 down), 3658 DE unigenes in G4 (2294 up and 1364 down), and 1511 DE unigenes in G5 (929 up and 582 down) compared with G1. Except in G2, lindane exposure caused significant impacts on cholinergic and GABAergic synaptic transmission in earthworms in other groups. The metabolic processes of ACh were also altered. It was of note that the term positive regulation of locomotion (GO:0040017) in G5 could be regarded as the phenotype of the interaction of two NTs. Conclusions: We found that aging of lindane prior to exposure promoted the disrupting effects of lindane on earthworm neurotransmission.
Project description:Frozen dough baking is useful method in the modern bread-making industry. However, the fermentation activity of baker’s yeast dramatically decreased after thawing due to freeze injuries, because baker’s yeast cells contained in dough experience freeze injuries during freeze-thaw processes. Here, we performed genome-wide expression analysis to determine genetic response in baker’s yeasts under freeze-thaw condition using a DNA microarray analysis. Functional and clustering analyses in gene expression reveal that genes could be characterized by the term of freeze-thaw stress. Under short-term freeze stress (freeze treatment for 3 day), genes involved in ribosomal protein were up-regulated. Under long-term freeze stress (freeze treatment for longer than 7 day), genes involved in energy synthesis were up-regulated. In each phase, genes involved in protein damage, several stresses and trehalose and glycogen metabolism were also up-regulated. Through these freeze stress, yeast cells may improve reduced efficiency of translation and enhanced cell protection mechanism to survive under freeze stress condition. These regulations of these genes would be controlled by the cAMP-protein kinase A pathway. Keywords: baker’s yeast, freeze-thaw stress, gene expression, freezing period