Soil Modification as a Restoration Tool to Reduce Old World Bluestems in Texas Coastal Prairies

Nonnative Old World bluestem (OWB) grasses (e.g., Bothriochloas, Dichanthium spp.) have become dominant throughout the southern and central Great Plains, altering native plant communities and habitat quality for wildlife. Although conventional management strategies have not resulted in elimination or reduction of these grasses, modifying soil conditions to favor native plants may be an alternative restoration tool. We examined efficacy of 10 soil modification treatments (soil disturbance alone, pH increase, pH reduction, carbon addition, addition of soil mycorrhizae, and each combined with seeding of native vegetation) on 60 research plots at the Welder Wildlife Foundation Refuge in southern Texas in summer 2011. We sampled soil chemistry, vegetation density, cover, and height, and abundance of soil, terrestrial, and flying arthropods four and eight weeks after initial treatments. Severe drought prevented plant growth on treated plots and may have decreased the efficacy of soil treatments, especially pH reduction. As such, we compared vegetation and arthropod communities only between undisturbed plots dominated by native vegetation and dominated by OWBs. Species richness of vegetation was higher on plots dominated by native vegetation (4.4 species/m2, SE = 0.6) compared to plots dominated by OWBs (2 species/m2, SE = 0.5). Arthropods were more abundant in native vegetation (175 individuals/m2, SE = 4.1) relative to OWB-dominated plant communities (41, 1.3). Isopods and ants were the most abundant groups overall, although some of these taxa are nonnative. We will continue to collect data over the next two years to explore further soil modification as a restoration tool in grasslands impacted by OWBs

Decreased Plant and Arthropod Richness in Landscapes Dominated by Old World Bluestem Grasses: Implications for Wildlife

Old World bluestem grasses (OWBs, e.g., Bothriochloa, Dichanthium spp.) have become dominant throughout the southern and central Great Plains, altering native plant communities with concomitant effects for native wildlife. We examined plant and arthropod communities in areas dominated by native plants and areas dominated by OWBs at the Welder Wildlife Refuge in southern Texas. We sampled vegetation and arthropods on research plots (6 x 9-m, 5 each) every 4 weeks during summer 2011 and 2012. We found, on average, 2 (SE=0.2) more plant species, and 12-13 (SE=1.0) more arthropod species on native plant-dominated plots compared to OWB-dominated plots. Native plant-dominated plots also had 273 (SE=18.8) more individual arthropods in 2011, but 75 (SE=16.6) fewer than OWB-dominant plots in 2012, resulting from a population explosion and crash of woodlice in native plant-dominated plots. We recorded only 1 species of herbivorous arthropod from OWB-dominated plots in 2012; native plant-dominated plots had 5-6 (SE=0.68) additional herbivore species, suggesting that increased dominance by OWBs may create cascading effects on trophic dynamics. Because many species of wildlife depend on plants and arthropods for food, these changes in species richness and abundance suggest that restoration tools are required to reduce the competitive ability of OWBs. Traditional management strategies have not successfully reduced OWBs; as part of our research, we are modifying soil properties to attempt to provide novel management strategies for landowners to increase diversity of native species and habitat quality in grasslands impacted by OWBs

‘Growing your own’: a multi-level modelling approach to understanding personal food growing trends and motivations in Europe

Growing food for personal and family consumption is a significant global activity, but one that has received insufficient academic attention, particularly in developed countries. This paper uses data from the European Quality of Life Survey (EQLS) to address three areas of particular concern: the prevalence of growing your own food and how this has changed over time; the individual and household context in which growing takes place; and whether those who grow their own food are happier than those who do not. Results showed that there was a marked increase in growing your own food in Europe, in the period 2003–2007. This increase is largely associated with poorer households and thus, possibly, economic hardship. In the UK however the increase in growing your own food is predominantly associated with older middle class households. Across Europe, whether causal or not, those who grew their own were happier than those who did not. The paper therefore concludes that claims about the gentrification of growing your own may be premature. Despite contrary evidence from the UK, the dominant motive across Europe appears to be primarily economic — to reduce household expenditure whilst ensuring a supply of fresh food

Long Term Transcriptional Reactivation of Epigenetically Silenced Genes in Colorectal Cancer Cells Requires DNA Hypomethylation and Histone Acetylation

Epigenetic regulation of genes involves the coordination of DNA methylation and histone modifications to maintain transcriptional status. These two features are frequently disrupted in malignancy such that critical genes succumb to inactivation. 5-aza-2′-deoxycytidine (5-aza-dC) is an agent which inhibits DNA methyltransferase, and holds great potential as a treatment for cancer, yet the extent of its effectiveness varies greatly between tumour types. Previous evidence suggests expression status after 5-aza-dC exposure cannot be explained by the DNA methylation status alone. Aim: We sought to identify chromatin changes involved with short and long term gene reactivation following 5-aza-dC exposure. Two colorectal cancer cell lines, HCT116 and SW480, were treated with 5-aza-dC and then grown in drug-free media to allow DNA re-methylation. DNA methylation and chromatin modifications were assessed with bisulfite sequencing and Chromatin Immuno-Precipitation analysis. Results: Increased H3 acetylation, H3K4 tri-methylation and loss of H3K27 tri-methylation were associated with reactivation. Hypermethylated genes that did not show increased acetylation were transiently expressed with 5-aza-dC treatment before reverting to an inactive state. Three reactivated genes, CDO1, HSPC105 and MAGEA3, were still expressed 10 days post 5-aza-dC treatment and displayed localised hypomethylation at the transcriptional start site, and also an increased enrichment of histone H3 acetylation. Conclusions: These observations suggest that hypomethylation alone is insufficient to reactivate silenced genes and that increased Histone H3 acetylation in unison with localised hypomethylation allows long term reversion of these epigenetically silenced genes. This study suggests that combined DNA methyltransferase and histone deacetylase inhibitors may aid long term reactivation of silenced genes

Human Cataract Mutations in EPHA2 SAM Domain Alter Receptor Stability and Function

The cellular and molecular mechanisms underlying the pathogenesis of cataracts leading to visual impairment remain poorly understood. In recent studies, several mutations in the cytoplasmic sterile-α-motif (SAM) domain of human EPHA2 on chromosome 1p36 have been associated with hereditary cataracts in several families. Here, we have investigated how these SAM domain mutations affect EPHA2 activity. We showed that the SAM domain mutations dramatically destabilized the EPHA2 protein in a proteasome-dependent pathway, as evidenced by the increase of EPHA2 receptor levels in the presence of the proteasome inhibitor MG132. In addition, the expression of wild-type EPHA2 promoted the migration of the mouse lens epithelial αTN4-1 cells in the absence of ligand stimulation, whereas the mutants exhibited significantly reduced activity. In contrast, stimulation of EPHA2 with its ligand ephrin-A5 eradicates the enhancement of cell migration accompanied by Akt activation. Taken together, our studies suggest that the SAM domain of the EPHA2 protein plays critical roles in enhancing the stability of EPHA2 by modulating the proteasome-dependent process. Furthermore, activation of Akt switches EPHA2 from promoting to inhibiting cell migration upon ephrin-A5 binding. Our results provide the first report of multiple EPHA2 cataract mutations contributing to the destabilization of the receptor and causing the loss of cell migration activity

The quest for molecular regulation underlying unisexual flower development

The understanding of the molecular mechanisms responsible for the making of a unisexual flower has been a long-standing quest in plant biology. Plants with male and female flowers can be divided mainly into two categories: dioecious and monoecious, and both sexual systems co-exist in nature in ca of 10% of the angiosperms. The establishment of male and female traits has been extensively described in a hermaphroditic flower and requires the interplay of networks, directly and indirectly related to the floral organ identity genes including hormonal regulators, transcription factors, microRNAs, and chromatin-modifying proteins. Recent transcriptomic studies have been uncovering the molecular processes underlying the establishment of unisexual flowers and there are many parallelisms between monoecious, dioecious, and hermaphroditic individuals. Here, we review the paper entitled "Comparative transcriptomic analysis of male and female flowers of monoecious Quercus suber" published in 2014 in the Frontiers of Plant Science (volume 5 |Article 599) and discussed it in the context of recent studies with other dioecious and monoecious plants that utilized high-throughput platforms to obtain transcriptomic profiles of male and female unisexual flowers. In some unisexual flowers, the developmental programs that control organ initiation fail and male or female organs do not form, whereas in other species, organ initiation and development occur but they abort or arrest during different species-specific stages of differentiation. Therefore, a direct comparison of the pathways responsible for the establishment of unisexual flowers in different species are likely to reveal conserved modules of gene regulatory hubs involved in stamen or carpel development, as well as differences that reflect the different stages of development in which male and/or female organ arrest or loss-of-function occurs.This work was funded by FEDER funds through the Operational CompetitivenessProgramme-COMPETE and by National Funds through FCT—Fundação para a Ciência e a Tecnologia under the project FCOMP—01—0124—FEDER—019461 (PTDC/AGRGPL/118508/2010) and the sub-project SOBREIRO/0019/2009 within the National Consortium (COEC—Cork Oak ESTs Consortium). RS was supported by funding from FCT with a PhD grant (ref. SFRH/BD/84365/2012). HS was supported by funding from FCT with a PhD grant (ref. SFRH/BD/111529/2015). MC was supported by funding from FCT with a grant SFRH/BSAB/113781/2015.info:eu-repo/semantics/publishedVersio