Acquisition of desiccation tolerance by isolated maize embryos exposed to different conditions: the questionable role of endogenous abscisic acid

The effect of exogenous ABA on acquisition of desiccation tolerance has been well documented for the embryos of several species. including maize ( Zea mays L.). It has also been suggested that endogenous ABA plays a role in regulating the same phenomena. To test this hypothesis, endogenous ABA was quantified by radioimmunoassay. Our results show that: (1) during embryogenesis in maize, endogenous ABA increase-concomitantly with the acquisition of desiccation tolerance: (2) ABA deficient embryos of the vp 5 mutant are desiccation intolerant, but tolerance can he induced by exogenous ABA: and (3) desiccation tolerance is acquired if desiccation sensitive embryos undergo a slow drying treatment, during which ABA increases. However, when embryos were preincubated in fluridone to prevent ABA accumulation during slow drying, desiccation tolerance was induced in spite of the low level of endogenous ABA in the embryo. Our results cast doubts on an exclusive role of ABA in the acquisition of desiccation tolerance in maize embryo.     

Environmental impacts of household goods in Europe: a process-based life cycle assessment model to assess consumption footprint

The International Journal of Life Cycle Assessment - Current patterns of household goods consumption generate relevant environmental pressures and impacts. Environmental impacts are not only...     

Correction to: The evolution of life cycle assessment in european policies over three decades

The International Journal of Life Cycle Assessment -     

National inventories of land occupation and transformation flows in the world for land use impact assessment

Purpose

Land use can cause significant impacts on ecosystems and natural resources. To assess these impacts using life cycle assessment (LCA) and ensure adequate decision-making, comprehensive national inventories of land occupation and transformation flows are required. Here, we aim at developing globally differentiated inventories of land use flows that can be used for primary use in life cycle impact assessment or national land planning.

Methods

Using publicly available data and inventory techniques, national inventories for several land use classes were developed. All land use classes were covered with the highest retrievable level of disaggregation within urban, forestry, agriculture and other land use classes, thus differentiating 21 land use classes. For illustrating the application of this newly developed inventory, two different application settings relevant to life cycle impact assessment were considered: the calculation of global normalisation references for 11 land use impact indicators related to soil quality assessment (adopting the methods recommended by the EU Commission) and the determination of generic globally applicable characterisation factors (CFs) resulting from aggregation of country-level CFs for situations for use when land use location is unknown.

Results and discussion

We built national inventories of 21 land occupation and 17 land transformation flows for 225 countries in the world for the reference year 2010. Cross-comparisons with existing inventories of narrower scopes attested its consistency. Detailed analyses of the calculated global normalisation references for the 11 land use impact categories showed different patterns across the land use impact indicators for each country, thus raising attention on key land use impacts specific to each country. Furthermore, the upscaling of country-level CFs to global generic CFs using the land use inventory revealed discrepancies with other alternative approaches using land use data at different resolutions.

Conclusions

In this study, we made a first attempt at developing national inventories of land use flows with sufficient disaggregation level to enable the calculation of normalisation references and differentiated impacts. However, the findings also demonstrated the need to refine the consistency of the inventory, particularly in the combination of land cover and land use data, which should be harmonised in future studies, and to expand it with differentiated coverage of more land use flows relevant to impact assessment.

     

Metabotropic Glutamate Receptors Stimulate Phospholipase D via Different Pathways in the Adult and Neonate Rat Hippocampus

In order to characterize the ontogenetic profile of metabotropic glutamate (mGlu) receptors coupled to phospholipase D (PLD) we examined the effects of selected mGlu agents on PLD activity in immature and adult rat hippocampus. The group I mGlu receptor agonist 3,5-dihydroxyphenylglycine stimulated PLD in immature tissue, but reduced the PLD response evoked by the nonselective mGlu receptor agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylate [(1S,3R)-ACPD] in adult hippocampus. (2R,1S,2R,3S)-2-(2-Carboxy-3-phenylcyclopropyl)glycine (PCCG-13), a recently characterized selective antagonist of PLD-coupled mGlu receptors, displayed a much greater activity in reducing the PLD response to (1S,3R)-ACPD in adult than in neonate hippocampus. Our results lend support to the hypothesis that glutamatergic activation of PLD in the rat hippocampus is developmentally regulated.     

Molecular Diversity of Anthracnose Pathogen Populations Associated with UK Strawberry Production Suggests Multiple Introductions of Three Different Colletotrichum Species

Fragaria × ananassa (common name: strawberry) is a globally cultivated hybrid species belonging to Rosaceae family. Colletotrichum acutatum sensu lato (s.l.) is considered to be the second most economically important pathogen worldwide affecting strawberries. A collection of 148 Colletotrichum spp. isolates including 67 C. acutatum s.l. isolates associated with the phytosanitary history of UK strawberry production were used to characterize multi-locus genetic variation of this pathogen in the UK, relative to additional reference isolates that represent a worldwide sampling of the diversity of the fungus. The evidence indicates that three different species C. nymphaeae, C. godetiae and C. fioriniae are associated with strawberry production in the UK, which correspond to previously designated genetic groups A2, A4 and A3, respectively. Among these species, 12 distinct haplotypes were identified suggesting multiple introductions into the country. A subset of isolates was also used to compare aggressiveness in causing disease on strawberry plants and fruits. Isolates belonging to C. nymphaeae, C. godetiae and C. fioriniae representative of the UK anthracnose pathogen populations showed variation in their aggressiveness. Among the three species, C. nymphaeae and C. fioriniae appeared to be more aggressive compared to C. godetiae. This study highlights the genetic and pathogenic heterogeneity of the C. acutatum s.l. populations introduced into the UK linked to strawberry production.     

Age-associated biomarker profiles of human breast cancer

To explore the hypothesis that aging not only increases breast cancer incidence but also alters breast cancer biology, we correlated patient age and diagnosis with tumor histology, stage and biomarkers independently determined from two different tumor archives: an American collection of approximately 800 paraffin-embedded and immunohistochemically analyzed primary breast cancers, and an European collection of approximately 3000 cryobanked primary breast cancers analyzed by ligand-binding and enzyme immunoassay (EIA). The prognostic biomarkers chosen for comparison represented surrogate measures of tumor: (i). proliferation, growth and genetic instability (mitotic and apoptotic indices, Ki-67/MIB-1-positivity, nuclear grade, p53-positivity), (ii). endocrine-dependence (estrogen receptor (ER), progesterone receptors (PR), pS2, Bcl2), (iii). growth factor receptor-dependence (ErbB2, EGFR/ErbB1), and (iv). angiogenic, invasive and proteolytic potential (uPA, PAI-1, Cathepsin D, VEGF). No biomarker reflecting tumor angiogenic, invasive or proteolytic potential showed a significant correlation with patient age at diagnosis. In contrast, significant inverse correlations (|r|>0.1; P< or =0.05) were observed for all measures of tumor growth and genetic instability as well as growth factor receptor overexpression (ErbB2 or EGFR positivity). Only one marker of endocrine-dependence, ER expression, showed a significant positive correlation with patient age at diagnosis. In summary, these findings support the hypothesis that breast cancer biology is significantly affected by patient age. In particular, breast tumors arising in older patients have slower growth rates, are more likely to be ER-positive, and are less likely to be p53-positive, EGFR-positive or ErbB2-positive.     

Potential role of HER2-overexpressing exosomes in countering trastuzumab-based therapy

Exosomes are endosome-derived nanovesicles actively released into the extracellular environment and biological fluids, both under physiological and pathological conditions, by different cell types. We characterized exosomes constitutively secreted by HER2-overexpressing breast carcinoma cell lines and analyzed in vitro and in vivo their potential role in interfering with the therapeutic activity of the humanized antibody Trastuzumab and the dual tyrosine kinase inhibitor (TKI) Lapatinib anti-HER2 biodrugs. We show that exosomes released by the HER2-overexpressing tumor cell lines SKBR3 and BT474 express a full-length HER2 molecule that is also activated, although to a lesser extent than in the originating cells. Release of these exosomes was significantly modulated by the growth factors EGF and heregulin, two of the known HER2 receptor-activating ligands and naturally present in the surrounding tumor microenvironment. Exosomes secreted either in HER2-positive tumor cell-conditioned supernatants or in breast cancer patients' serum bound to Trastuzumab. Functional assays revealed that both xenogeneic and autologous HER2-positive nanovesicles, but not HER2-negative ones, inhibited Trastuzumab activity on SKBR3 cell proliferation. By contrast, Lapatinib activity on SKBR3 cell proliferation was unaffected by the presence of autologous exosomes. Together, these findings point to the role of HER2-positive exosomes in modulating sensitivity to Trastuzumab, and, consequently, to HER2-driven tumor aggressiveness.