Project description:The absorption of visible light in aquatic environments has led to the common assumption that aquatic organisms sense and adapt to penetrative blue/green light wavelengths, but show little or no response to the more attenuated red/far-red wavelengths. Here we show that two marine diatom species, Phaeodactylum tricornutum and Thalassiosira pseudonana, possess a bona fide red/far-red light sensing phytochrome (DPH) that uses biliverdin as a chromophore and displays accentuated red-shifted absorbance peaks compared to other characterized plant and algal phytochromes. Exposure to both red and far-red light causes changes in gene expression in P. tricornutum and the responses to far-red light disappear in DPH knockout cells, demonstrating that P. tricornutum DPH mediates far-red light signaling. The identification of DPH genes in diverse diatom species widely distributed along the water column further emphasizes the ecological significance of far-red light sensing, raising questions about the sources of far-red light. Our analyses indicate that, although far-red wavelengths from sunlight are only detectable at the ocean surface, chlorophyll fluorescence and Raman scattering can generate red/far-red photons in deeper layers. This study opens up novel perspectives on phytochrome-mediated far-red light signaling in the ocean and on the light sensing and adaptive capabilities of marine phototrophs.
Project description:Coral reefs worldwide are facing rapid decline due to coral bleaching. However, knowledge of the physiological characteristics and molecular mechanisms of coral symbionts respond to stress is scarce. Here, metagenomic and metaproteomic approach were utilized to shed light on the changes in the composition and functions of coral symbionts during coral bleaching. The results demonstrated that coral bleaching significantly affected the composition of symbionts, with bacterial communities dominating in bleached corals. Difference analysis of gene and protein indicated that symbiont functional disturbances in response to heat stress, resulting in abnormal energy metabolism that could potentially compromise symbiont health and resilience. Furthermore, our findings highlighted the highly diverse microbial communities of coral symbionts, with beneficial bacteria provide critical services to corals in stress responses, while pathogenic bacteria drive coral bleaching. This study provides comprehensive insights into the complex response mechanisms of coral symbionts under thermal stress and offers fundamental data for future monitoring of coral health.
Project description:We performed four small RNA sequencing for identification and characterization of microRNAs in Phalaenopsis aphrodite subsp. formosana. By comparing the low temperature-treated group with treated group, we concluded four miRNAs - miR156, miR162, miR528 and miR535 - as low temperature-induced miRNAs. In addition, tissue-specific expression of these miRNAs was investigated. The files contain the miRNAs analysis results in each group. Examination of low temperature-treated leaves and two other organs of Phalaenopsis orchid
Project description:Phosphorus (P) is a critical driver of phytoplankton growth and ecosystem structure and function in the ocean. Diatoms are an abundant and widespread functional group of phytoplankton that are responsible for significant amounts of primary production in the ocean, however there has not been a comprehensive study of diatom physiological responses to P deficiency. Here, we coupled deep sequencing of transcript tags and quantitative proteomic analysis from the diatom Thalassiosira pseudonana grown under P-replete and P-deficient conditions. The reads (tags) were mapped to the T. pseudonana genome sequence, confirming expression of 91% of the modeled gene set. A total of 318 genes were differentially regulated with a false discovery rate of p<0.05. A total of 1264 proteins were detected, and of those 136 were differentially expressed with a false discovery rate of p<0.05. Significant changes in the abundance of transcripts and proteins were observed and these changes were coordinated for glycolysis, translation, and multiple biochemical responses to P deficiency. These data demonstrate that diatom P deficiency results in changes in cellular P allocation through polyphosphate production, increased P transport, a switch to utilization of dissolved organic P (DOP) through increased production of alkaline phosphatase metalloenzymes and a diesterase, and a remodeling of the cell surface through production of sulfolipids. Together, these findings reveal that T. pseudonana has evolved a sophisticated response to P deficiency involving multiple biochemical strategies that are likely critical to its ability to rapidly respond to variations in environmental P availability.
Project description:GLEAMS is a deep neural network to embed spectra into a low-dimensional space in which spectra generated by the same peptide are close to one another. We have used GLEAMS as the basis for a large-scale spectrum clustering, detecting groups of unidentified, proximal spectra representing the same peptide.
GLEAMS was used to embed 669 million spectra from the MassIVE-KB dataset, after which hierarchical clustering with average linkage was used to cluster the embeddings. Medoid spectra were extracted from clusters consisting of only unidentified spectra, resulting in 45 million medoid spectra representing 257 million clustered spectra. The medoid spectra were split into two groups based on cluster size (size two and size greater than two) and exported to two MGF files. ANN-SoLo was used for open modification searching, identifying 5.3 million peptide-spectrum matches.
We here present the originally unidentified cluster medoid spectra and the ANN-SoLo identification results as a community resource. This is a valuable dataset to further explore the dark proteome, by investigating spectra that are observed repeatedly across many experiments but consistently remain unidentified.