Project description:Background: The Scylla paramamosain is a very important aquaculture crustacean species in the southeast coastal areas of China including Shantou. For the past few years, mud crab cultured in Niutianyang of Shantou suffered from serious diseases, especially the bacterial diseases (such as Vibrio parahaemolyticus). In eukaryotes, small RNAs can regulate gene expression in post-transcription to act on host-pathogen interaction system. Aims: V.parahaemolyticus isolated from Shantou Niutianyang crab culture area was injected to S.paramamosains to carry out an essential analysis on global miRNA expression in diverse tissues between two groups by the Illumina Solex deep sequencing technology. Methodology:To examine the relationship between mud crab miRNA expression and the bacterial pathogen, we collected mixed two pools of equal amounts of RNA from 7 different mud crab tissues (mesenteron, heart, liver, gill, brain, muscle and blood) and sequencing by Illumine/Solexa deep sequencing technology under normal conditions and during infection with V.parahaemolyticus. The high throughput sequencing resulted in 19,144,358 and 18,559,070 raw reads corresponding to 17,496,577 and 16,888,096 high-quality mappable reads for the normal and infected mixed pools, respectively. Stem-loop RT-qPCRs were used to confirm the microRNAs expression in different tissues of two pools. The results show that miRNAs might play a key role in regulating gene expression during mud crab S.paramamosain infection with V.parahaemolyticus. Conclusions: We identified a large number of miRNAs during the mud crab Scylla paramamosain infection with V.parahaemolyticus, some of which are differentially expressed between the treatments and the controls. The study provides an opportunity for further understanding of small RNA function in the regulation of molecular response and gives us clues for further studies of the mechanisms of V.parahaemolyticus infection in mud crab.
Project description:Background: The Scylla paramamosain is a very important aquaculture crustacean species in the southeast coastal areas of China including Shantou. For the past few years, mud crab cultured in Niutianyang of Shantou suffered from serious diseases, especially the bacterial diseases (such as Vibrio parahaemolyticus). In eukaryotes, small RNAs can regulate gene expression in post-transcription to act on host-pathogen interaction system. Aims: V.parahaemolyticus isolated from Shantou Niutianyang crab culture area was injected to S.paramamosains to carry out an essential analysis on global miRNA expression in diverse tissues between two groups by the Illumina Solex deep sequencing technology. Methodology:To examine the relationship between mud crab miRNA expression and the bacterial pathogen, we collected mixed two pools of equal amounts of RNA from 7 different mud crab tissues (mesenteron, heart, liver, gill, brain, muscle and blood) and sequencing by Illumine/Solexa deep sequencing technology under normal conditions and during infection with V.parahaemolyticus. The high throughput sequencing resulted in 19,144,358 and 18,559,070 raw reads corresponding to 17,496,577 and 16,888,096 high-quality mappable reads for the normal and infected mixed pools, respectively. Stem-loop RT-qPCRs were used to confirm the microRNAs expression in different tissues of two pools. The results show that miRNAs might play a key role in regulating gene expression during mud crab S.paramamosain infection with V.parahaemolyticus. Conclusions: We identified a large number of miRNAs during the mud crab Scylla paramamosain infection with V.parahaemolyticus, some of which are differentially expressed between the treatments and the controls. The study provides an opportunity for further understanding of small RNA function in the regulation of molecular response and gives us clues for further studies of the mechanisms of V.parahaemolyticus infection in mud crab. Examination of miRNA expression in normal Scylla paramamosain group and the Scylla paramamosain infected with Vibrio parahaemolyticus
Project description:Antagonism between P.donghuensis SVBP6, biocontrol soil bacteria, and M.phaseolina on potato dextrose agar. Untargeted metabolomics of ethyl acetate extracts. Fungal, bacterial, and interaction agar samples.
Project description:<p>Drought stress negatively impacts microbial activity, but the magnitude of stress responses are likely dependent on a diversity of below ground interactions. Populus trichocarpa individuals and no plant bulk soils were exposed to extended drought (~0.03% gravimetric water content (GWC) after 12d), re-wet, and a 12-d 'recovery' period to determine the effects of plant presence in mediating soil microbiome stability to water stress. Plant metabolomic analyses indicated that drought exposure increased host investment in C and N metabolic pathways (amino acids, fatty-acids, phenolic glycosides) regardless of recovery. Several metabolites positively correlated with root-associated microbial alpha diversity, but not those of soil communities. Soil bacterial community composition shifted with P. trichocarpa presence and with drought relative to irrigated controls, whereas soil fungal composition only shifted with plant presence. However, root fungal communities strongly shifted with drought, whereas root bacterial communities changed to a lesser degree. The proportion of bacterial water-stress opportunistic OTUs (enriched counts in drought) were high (~11%) at the end of drying phases, and maintained after re-wet, and recovery phases in bulk soils, but declined over time in soils with plants present. For root fungi opportunistic OTUs were high at the end of recovery in drought treatments (~17% abundance), although relatively not responsive in soils, particularly planted soils (< 0.5% abundance for sensitive or opportunistic). These data indicate that plants modulate soil and root associated microbial drought responses via tight plant-microbe linkages during extreme drought scenarios, but trajectories after extreme drought vary with plant habitat and microbial functional groups.</p>
Project description:Because of severe abiotic limitations, Antarctic soils represent simplified ecosystems, where microorganisms are the principle drivers of nutrient cycling. This relative simplicity makes these ecosystems particularly vulnerable to perturbations, like global warming, and the Antarctic Peninsula is among the most rapidly warming regions on the planet. However, the consequences of the ongoing warming of Antarctica on microorganisms and the processes they mediate are unknown. Here, using 16S rRNA gene pyrosequencing and qPCR, we report a number of highly consistent changes in microbial community structure and abundance across very disparate sub-Antarctic and Antarctic environments following three years of experimental field warming (+ 0.5-2°C). Specifically, we found significant increases in the abundance of fungi and bacteria and in the Alphaproteobacteria-to-Acidobacteria ratio. These alterations were linked to a significant increase in soil respiration. Furthermore, the shifts toward generalist or opportunistic bacterial communities following warming weakened the linkage between bacterial diversity and functional diversity. Warming also increased the abundance of some organisms related to the N-cycle, detected as an increase in the relative abundance of nitrogenase genes via GeoChip microarray analyses. Our results demonstrate that soil microorganisms across a range of sub-Antarctic and Antarctic environments can respond consistently and rapidly to increasing temperatures, thereby potentially disrupting soil functioning. We conducted in situ warming experiments for three years using open-top chambers (OTCs) at one sub-Antarctic (Falkland Islands, 52ºS) and two Antarctic locations (Signy and Anchorage Islands, 60ºS and 67ºS respectively) (see Supplementary Fig. 1 for a map). OTCs increased annual soil temperature by an average of 0.8°C (at a depth of 5 cm), resulting in 8-43% increase in positive-degree days annually and a decrease in freeze-thaw cycle frequency by an average of 15 cycles per year (8). At each location, we included densely vegetated and bare fell-field soils in the experimental design for a total of six environments. Densely vegetated and bare environments represent two contrasting environments for Antarctic soil microorganisms, with large differences in terms of C and N inputs to soils. Massively parallel pyrosequencing (Roche 454 GS FLX Titanium) of 16S rRNA gene amplicons was used to follow bacterial diversity and community composition [GenBank Accession Numbers: HM641909-HM744649], and functional gene microarrays (GeoChip 2.0)(11) were used to assess changes in functional gene distribution. Bacterial and fungal communities were also quantified using real-time PCR.