Keywords: SOUTH AFRICA/ POPULAR
Abstract: 14 figures (12 in color). [A popular article on South African lichens with beautiful color photographs.]
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Keywords: CHEMISTRY/ GREAT SMOKY MOUNTAINS/ MOLECULAR PHYLOGENY/ PHYLOGENETICS/ SOUTHERN APPALACHIANS/ STICTA/ NAID
Abstract: 7 fig. 3 tab. [New: Sticta carolinensis McDonald sp. nov. (Arkansas, Alabama, North Carolina, South Carolina, Tennessee, Georgia, Mississippi), S. fragilanata McDonald sp. nov. (North Carolina, Tennessee, Georgia, Florida).]
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[ET: 3843]
URL: http://genomicscience.energy.gov/pubs/2011abstracts/2011GSPabstracts_webprint.pdf
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Keywords: DIFFERENTIAL ACTIVITY/ MITOTIC KINASES/ PURIFIED RECOMBINANT PLK1 KINASE
Abstract: [In exploring natural sources for anti-cancer drug leads, extracts of Parmotrema sp. show promise of activity in a cellular environment.]
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Abstract: In this study we describe the techniques used to culture 25 mycobionts spanning three classes and five orders of the leotiomyceta (Ascomycota). We find that five media, including potato-carrot, malt extract-yeast extract (MY), Bold’s basal medium with nitrogen (NMBBM), oatmeal, and yeast extract with supplements (YES), are sufficient to induce ascospore germination of many lichenizing fungi and are also suitable for maintaining growth of the culture over the long term. Regular physical disruption of the cultures in liquid media is recommended to stimulate continued growth. Genomes of five of these lichen-forming fungal strains have been sequenced. The identity of each culture was confirmed by sequencing the nuclear ribosomal internal transcribed spacer (ITS) or the mitochondrial small subunit (mitSSU) from each strain. Additionally, the level of sequencing in terms of total number of genes sequenced for each taxon is provided. All fungal cultures have been deposited in public culture collections and, therefore, are available to the scientific community for conducting in vitro experiments.
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Keywords: CONSERVATION/ FUNGI/ ITS/ MOLECULAR BARCODING/ TAXONOMY
Abstract: The presence of the foliose cyanolichen Sticta sylvatica in eastern North America has been called into question due to the absence of high-quality, verifiable material and the common misuse of its name. Recently, specimens collected in the Great Smoky Mountains have been verified as having the typical S. sylvatica morphology. Although molecular data remain inconclusive regarding the entity's genetic distinctiveness from the phenotypically dissimilar S. limbata, we argue that the decline in the abundance of this morphological entity worldwide along with the need for further genetic study make continued conservation efforts imperative.
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Abstract: Tree bark characteristics influence lichen colonization. To better understand how urban parks can be managed to maximize lichen biodiversity, we examined trees in seven parks throughout the City of Guelph in southern Ontario. We measured bark characteristics and lichen communities on four common tree species that have a wide range of pH: Acer platanoides L., Acer × freemanii E. Murray, Pinus resinosa Aiton, and Pinus strobes L. We recorded the lichen species on 99 trees, calculated the pH and fissuring of the bark, and determined the diameter at breast height (DBH) as a proxy for age. Gamma diversity on all trees included 18 lichen taxa. We used graphite bark rubbings analyzed in ImageJ 1.47v to calculate the degree of bark fissuring. We collected bark samples from each tree trunk and determined the acidity with a pH meter. Using multivariate analyses we show that lichen community composition is positively correlated with DBH and tree species, but the degree of fissuring did not have a significant effect. We could not statistically analyze pH independent of tree species, but our results suggest pH is not a significant variable. We show lichen biodiversity in urban parks can be increased by planting a variety of tree species at different ages.
Countries/Continents: Canada/North America
URL: http://www.nrcresearchpress.com/doi/abs/10.1139/cjb-2017-0113#.WiXP5jdrw2w
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Abstract: Background: Lichens, encompassing 20,000 known species, are symbioses between specialized fungi (mycobionts), mostly ascomycetes, and unicellular green algae or cyanobacteria (photobionts). Here we describe the first parallel genomic analysis of the mycobiont Cladonia grayi and of its green algal photobiont Asterochloris glomerata. We focus on genes/predicted proteins of potential symbiotic significance, sought by surveying proteins differentially activated during early stages of mycobiont and photobiont interaction in coculture, expanded or contracted protein families, and proteins with differential rates of evolution. Results: A) In coculture, the fungus upregulated small secreted proteins, membrane transport proteins, signal transduction components, extracellular hydrolases and, notably, a ribitol transporter and an ammonium transporter, and the alga activated DNA metabolism, signal transduction, and expression of flagellar components. B) Expanded fungal protein families include heterokaryon incompatibility proteins, polyketide synthases, and a unique set of G-protein α subunit paralogs. Expanded algal protein families include carbohydrate active enzymes and a specific subclass of cytoplasmic carbonic anhydrases. The alga also appears to have acquired by horizontal gene transfer from prokaryotes novel archaeal ATPases and Desiccation-Related Proteins. Expanded in both symbionts are signal transduction components, ankyrin domain proteins and transcription factors involved in chromatin remodeling and stress responses. The fungal transportome is contracted, as are algal nitrate assimilation genes. C) In the mycobiont, slow-evolving proteins were enriched for components involved in protein translation, translocation and sorting. Conclusions: The surveyed genes affect stress resistance, signaling, genome reprogramming, nutritional and structural interactions. The alga carries many genes likely transferred horizontally through viruses, yet we found no evidence of inter-symbiont gene transfer. The presence in the photobiont of meiosis-specific genes supports the notion that sexual reproduction occurs in Asterochloris while they are free-living, a phenomenon with implications for the adaptability of lichens and the persistent autonomy of the symbionts. The diversity of the genes affecting the symbiosis suggests that lichens evolved by accretion of many scattered regulatory and structural changes rather than through introduction of a few key innovations. This predicts that paths to lichenization were variable in different phyla, which is consistent with the emerging consensus that ascolichens could have had a few independent origins.
URL: https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-019-5629-x
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Abstract: Premise The long-term potential for acclimation by lichens to changing climates is poorly known, despite their prominent roles in forested ecosystems. Although often considered “extremophiles,” lichens may not readily acclimate to novel climates well beyond historical norms. In a previous study (Smith et al., 2018), Evernia mesomorpha transplants in a whole-ecosystem climate change experiment showed drastic mass loss after 1 yr of warming and drying; however, the causes of this mass loss were not addressed. Methods We examined the causes of this warming-induced mass loss by measuring physiological, functional, and reproductive attributes of lichen transplants. Results Severe loss of mass and physiological function occurred above +2°C of experimental warming. Loss of algal symbionts (“bleaching”) and turnover in algal community compositions increased with temperature and were the clearest impacts of experimental warming. Enhanced CO2 had no significant physiological or symbiont composition effects. The functional loss of algal photobionts led to significant loss of mass and specific thallus mass (STM), which in turn reduced water-holding capacity (WHC). Although algal genotypes remained detectable in thalli exposed to higher stress, within-thallus photobiont communities shifted in composition toward greater diversity. Conclusions The strong negative impacts of warming and/or lower humidity on Evernia mesomorpha were driven by a loss of photobiont activity. Analogous to the effects of climate change on corals, the balance of symbiont carbon metabolism in lichens is central to their resilience to changing conditions.
Countries/Continents: U.S.A/North America
URL: https://doi.org/10.1002/ajb2.16114
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Number of records in database: 53544.
Current date: 2024.04.25.OK