Project description:The objective was to identify functional genes encoded by Fungi and fungal-like organisms to assess putative ecological roles Using the GeoChip microarray, we detected fungal genes involved in the complete assimilation of nitrate and the degradation of lignin, as well as evidence for Partitiviridae (a mycovirus) that likely regulates fungal populations in the marine environment. These results demonstrate the potential for fungi to degrade terrigenously-sourced molecules, such as permafrost and compete with algae for nitrate during blooms. Ultimately, these data suggest that marine fungi could be as important in oceanic ecosystems as they are in freshwater environments.
Project description:The collapses of the Larsen A and B ice shelves on the Antarctic Peninsula in 1995 and 2002 confirm the impact of southward-propagating climate warming in this region. Recent mass and dynamic changes of Larsen B's southern neighbour Larsen C, the fourth largest ice shelf in Antarctica, may herald a similar instability. Here, using a validated ice-shelf model run in diagnostic mode, constrained by satellite and in situ geophysical data, we identify the nature of this potential instability. We demonstrate that the present-day spatial distribution and orientation of the principal stresses within Larsen C ice shelf are akin to those within pre-collapse Larsen B. When Larsen B's stabilizing frontal portion was lost in 1995, the unstable remaining shelf accelerated, crumbled and ultimately collapsed. We hypothesize that Larsen C ice shelf may suffer a similar fate if it were not stabilized by warm and mechanically soft marine ice, entrained within narrow suture zones.
Project description:Marine sediments harbor highly diverse microbial communities that contribute to global biodiversity and play essential roles in the ecosystem functioning. However, the metaproteome of marine sediments remains poorly understood. Extracting proteins from environmental samples can be challenging, especially in marine sediments due to their complex matrix. Few studies have been conducted on improving protein extraction methods from marine sediments. To establish an effective protein extraction workflow for clay-rich sediments, we compared, combined and improved several protein extraction methods. The presented workflow includes blocking of protein binding sites on sediment particles with high concentrations of amino acids, effective cell lysis via ultra-sonication, and the electro-elution and simultaneous fractionation of proteins. Using this workflow, we were able to recover 100% of the previously added Escherichia coli proteins from the sediment.
Project description:Lettuce (Lactuca sativa L.) is a highly perishable horticultural crop with a relatively short shelf life due to leaf senescence that limits its commercial value and contributes to food waste. Postharvest senescence varies with influences of both environmental and genetic factors. Preharvest genetic factors can be indicative of postharvest quality. Discovery of additional preharvest markers to assess lettuce shelf life is an important step towards increasing the efficiency of lettuce breeding efforts for improved shelf life. We selected and evaluated three romaine lettuces with variable shelf lives with the aim of identifying preharvest markers of lettuce postharvest shelf life. We evaluated leaf morphological characteristics for each of the three cultivars. To assess molecular indicators of shelf life, we used an RNA sequencing approach to construct transcriptomic profiles of two of the cultivars, a short shelf life (SSL) breeding line 60184 and a long shelf life (LSL) cultivar ‘Okeechobee’ at maturity. We identified 552 upregulated and 315 downregulated differentially expressed (DE) genes between the genotypes. We found that 27 % of the DE lettuce genes had an Arabidopsis thaliana ortholog characterized as senescence-associated, indicating that variable expression of senescence-associated genes (SAGs) could serve as a tool for preharvest markers of postharvest shelf life. Notably, we identified several SAGs and functional groupings with highly differential expression between the cultivars. This includes several jasmonate ZIM-domain (JAZ), jasmonic acid (JA) signaling genes, chlorophyll a-b binding (CAB) chloroplast-associated genes, and cell wall modification genes including pectate lyases (PL) and expansins (EXP). This study presented an innovative approach for identifying molecular markers for preharvest factors linked to postharvest traits for prolonged shelf. These genes could potentially be developed further as preharvest predictors of shelf life for lettuce breeding