Project description:Rationale Microplastics are a pressing global concern and inhalation of microplastic fibers has been associated with interstitial and bronchial inflammation in flock workers. However, how microplastic fibers affect the lungs is unknown. Objectives Our aim was to assess the effects of 12x31 µm nylon 6,6 (nylon) and 15x52 µm polyethylene terephthalate (polyester) textile microplastic fibers on lung epithelial growth and differentiation. Methods We used human and murine alveolar and airway-type organoids as well as air-liquid interface cultures derived from primary lung epithelial progenitor cells and incubated these with either nylon or polyester fibers or nylon leachate. In addition, mice received one dose of nylon fibers or nylon leachate and 7 days later organoid-forming capacity of isolated epithelial cells was investigated. Results We observed that nylon microfibers, more than polyester, inhibited developing airway organoids and not established ones. This effect was mediated by components leaching from nylon. Epithelial cells isolated from mice exposed to nylon fibers or leachate, also formed fewer airway organoids, suggesting long-lasting effects of nylon components on epithelial cells. Part of these effects were recapitulated in human air-liquid interface cultures. Transcriptome analysis revealed upregulation of Hoxa5 post-exposure to nylon fibers. Inhibiting Hoxa5 protein during nylon exposure restored airway organoid formation, confirming Hoxa5's pivotal role in the effects of nylon. Conclusions These results suggest that components leaching from nylon 6,6 may especially harm developing airways and/or airways undergoing repair and we strongly encourage to characterize both hazard of and exposure to microplastic fibers in more detail.
Project description:Drought is a stressor for many soil-inhabiting organisms. Although plants have been extensively investigated for drought-adaptive mechanisms, little information is available for fungi. Antioxidants are especially relevant, since desiccation is accompanied by an excessive intracellular production of reactive oxygen species. Riboflavin (vitamin B2) is one antioxidant regulating drought tolerance in plants. A similar function may exist in fungi. Here, we examined the respiratory and transcriptional responses of Agaricus bisporus to drought and the impact of riboflavin. Mesocosm experiments with four groups were established: hyphae were treated with or without 50 µM riboflavin under drought or no drought conditions. Drought increased riboflavin content in hyphae about 5 times with, but also without, addition of riboflavin. Without addition of riboflavin, fungal respiration decreased by more than 50% at water potentials of about -20 MPa. With addition of riboflavin, respiration remained about 2-3 times higher. The transcriptional responses to only drought or only riboflavin strongly overlapped and were mainly based on factors regulating transcription and translation. This was even stronger in combined treatments. Riboflavin induced protective mechanisms in drought-stressed hyphae. Most pronounced was the methylglyoxal (cytotoxic by-product of glycolysis) detoxifying of lactoylglutathione lyase. Thus, our data suggest a stress-priming function and a role of riboflavin in drought responses of A. bisporus.
Project description:Drought tolerance is a key trait for increasing and stabilizing barley productivity in dry areas worldwide. Identification of the genes responsible for drought tolerance in barley (Hordeum vulgare L.) will facilitate understanding of the molecular mechanisms of drought tolerance, and also genetic improvement of barley through marker-assisted selection or gene transformation. To monitor the changes in gene expression at transcription levels in barley leaves during the reproductive stage under drought conditions, the 22K Affymetrix Barley 1 microarray was used to screen two drought-tolerant barley genotypes, Martin and Hordeum spontaneum 41-1 (HS41-1), and one drought-sensitive genotype Moroc9-75. Seventeen genes were expressed exclusively in the two drought-tolerant genotypes under drought stress, and their encoded proteins may play significant roles in enhancing drought tolerance through controlling stomatal closure via carbon metabolism (NADP malic enzyme (NADP-ME) and pyruvate dehydrogenase (PDH), synthesizing the osmoprotectant glycine-betaine (C-4 sterol methyl oxidase (CSMO), generating protectants against reactive-oxygen-species scavenging (aldehyde dehydrogenase (ALDH), ascorbate-dependant oxidoreductase (ADOR), and stabilizing membranes and proteins (heat-shock protein 17.8 (HSP17.8) and dehydrin 3 (DHN3). Moreover, 17 genes were abundantly expressed in Martin and HS41-1 compared with Moroc9-75 under both drought and control conditions. These genes were likely constitutively expressed in drought-tolerant genotypes. Among them, 7 known annotated genes might enhance drought tolerance through signaling (such as calcium-dependent protein kinase (CDPK) and membrane steroid binding protein (MSBP), anti-senescence (G2 pea dark accumulated protein GDA2) and detoxification (glutathione S-transferase (GST) pathways. In addition, 18 genes, including those encoding Δl-pyrroline-5-carboxylate synthetase (P5CS), protein phosphatase 2C-like protein (PP2C) and several chaperones, were differentially expressed in all genotypes under drought; thus, they were more likely general drought-responsive genes in barley. These results could provide new insights into further understanding of drought-tolerance mechanisms in barley.
Project description:Drought tolerance is a key trait for increasing and stabilizing barley productivity in dry areas worldwide. Identification of the genes responsible for drought tolerance in barley (Hordeum vulgare L.) will facilitate understanding of the molecular mechanisms of drought tolerance, and also genetic improvement of barley through marker-assisted selection or gene transformation. To monitor the changes in gene expression at transcription levels in barley leaves during the reproductive stage under drought conditions, the 22K Affymetrix Barley 1 microarray was used to screen two drought-tolerant barley genotypes, Martin and Hordeum spontaneum 41-1 (HS41-1), and one drought-sensitive genotype Moroc9-75. Seventeen genes were expressed exclusively in the two drought-tolerant genotypes under drought stress, and their encoded proteins may play significant roles in enhancing drought tolerance through controlling stomatal closure via carbon metabolism (NADP malic enzyme (NADP-ME) and pyruvate dehydrogenase (PDH), synthesizing the osmoprotectant glycine-betaine (C-4 sterol methyl oxidase (CSMO), generating protectants against reactive-oxygen-species scavenging (aldehyde dehydrogenase (ALDH), ascorbate-dependant oxidoreductase (ADOR), and stabilizing membranes and proteins (heat-shock protein 17.8 (HSP17.8) and dehydrin 3 (DHN3). Moreover, 17 genes were abundantly expressed in Martin and HS41-1 compared with Moroc9-75 under both drought and control conditions. These genes were likely constitutively expressed in drought-tolerant genotypes. Among them, 7 known annotated genes might enhance drought tolerance through signaling (such as calcium-dependent protein kinase (CDPK) and membrane steroid binding protein (MSBP), anti-senescence (G2 pea dark accumulated protein GDA2) and detoxification (glutathione S-transferase (GST) pathways. In addition, 18 genes, including those encoding Δl-pyrroline-5-carboxylate synthetase (P5CS), protein phosphatase 2C-like protein (PP2C) and several chaperones, were differentially expressed in all genotypes under drought; thus, they were more likely general drought-responsive genes in barley. These results could provide new insights into further understanding of drought-tolerance mechanisms in barley. Seven flag leaves of a replication for each genotype were harvested at 0 d, 1 d, 3 d and 5 d after reach 10% of AWC in the soil to constitute a single biological replicate. These flag leaves were employed for RNA isolation by using Trizol reagent following the manufacturer’s protocol (Invitrogen, Karlsruhe, Germany). The RNA was further purified using RNeasy Kit (Qiagen, Hilden, Germany). RNA yield and quality were determined by using an Agilent 2100 Bioanalyzer (Agilent Techologies, Boblingen, Germany). A table of the average, log2 RMA signal intensity values of three biological replicates for each Sample is linked below as a supplementary file.
Project description:Plants coexist in close proximity with numerous microorganisms in their rhizosphere. With certain microorganisms, plants establish mutualistic relationships that can confer physiological benefits to the interacting organisms, including enhanced nutrient assimilation or increased stress tolerance. The root-colonizing endophytic fungi Penicillium chrysogenum, Penicillium minioluteum, and Serendipita indica have been reported to enhance the drought stress tolerance of plants. However, to date, the molecular mechanisms triggered by these fungi in plants remain unexplored. This study presents a comparative analysis of the effects on mock- and fungus-infected tomato plants (var. Moneymaker) under drought stress conditions (40% field capacity) and control conditions (100% field capacity). The findings provide evidence for the induction of common response modules by the fungi.