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Analogues of vertebrate natriuretic peptides (NPs) present in plants, termed plant natriuretic peptides (PNPs), comprise a novel class of hormones that systemically affect salt and water balance and responses to plant pathogens. Several... more
Analogues of vertebrate natriuretic peptides (NPs) present in plants, termed plant natriuretic peptides (PNPs), comprise a novel class of hormones that systemically affect salt and water balance and responses to plant pathogens. Several lines of evidence indicate that Arabidopsis thaliana PNP (AtPNP-A) affects cellular redox homeostasis, which is also typical for the signaling of its vertebrate analogues, but the molecular mechanism(s) of this effect remains elusive. Here we report identification of catalase 2 (CAT2), an antioxidant enzyme, as an interactor of AtPNP-A. The full-length AtPNP-A recombinant protein and the biologically active fragment of AtPNP-A bind specifically to CAT2 in surface plasmon resonance (SPR) analyses, while a biologically inactive scrambled peptide does not. In vivo bimolecular fluorescence complementation (BiFC) showed that CAT2 interacts with AtPNP-A in chloroplasts. Furthermore, CAT2 activity is lower in homozygous atpnp-a knockdown compared with wild ...
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... This occurs even in other grasses (Christensen and Homer, 1974), but not in rye-grass where proplastid differentiation into amyloplasts is ... recently been observed in potato tubers, dividing by binary fission to produce two... more
... This occurs even in other grasses (Christensen and Homer, 1974), but not in rye-grass where proplastid differentiation into amyloplasts is ... recently been observed in potato tubers, dividing by binary fission to produce two amyloplasts (Mingo-Castel, Pelacho and de Felipe, 1991 ...
Research Interests: Plant Biology and Ecology
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Two cases of zinc deficiency in breastfed neonates were investigated where zinc levels in the mothers' milk were reduced by more than 75 % compared to normal. The objective of this study was to find the molecular basis of the maternal... more
Two cases of zinc deficiency in breastfed neonates were investigated where zinc levels in the mothers' milk were reduced by more than 75 % compared to normal. The objective of this study was to find the molecular basis of the maternal zinc deficiency condition. Significant reductions in mRNA expression and protein levels of the zinc transporters SLC30A5 and SLC30A6 were found in maternal tissue, suggesting a causal link to the zinc-deficient milk. Novel splice variants of the SLC30A6 transcript were detected. No modifications were found in coding regions, or in transcription binding sites of promoter regions or in 5' and 3' untranslated regions of both transporters in lymphoblasts and fibroblasts isolated from both mothers. Altered DNA methylation in SLC30A5 at two CpG sites was detected and may account for the reduced levels of SLC30A5 mRNA and protein in lymphoblasts. Reduced SLC30A6 mRNA and protein levels in lymphoblasts may be secondary to reduced SLC30A5 expression...
Primary bioaerosols include those that evolved to enable reproduction and propagation (pollen, spores, bacteria, viruses, etc.) and fragmentary particles whose origins are often linked to anthropogenic activities such as agriculture,... more
Primary bioaerosols include those that evolved to enable reproduction and propagation (pollen, spores, bacteria, viruses, etc.) and fragmentary particles whose origins are often linked to anthropogenic activities such as agriculture, waste processing, roadway abrasion. Natural fragmentation processes have often been linked to dispersal from water surfaces by wave breaking and bubble bursting. Fragmentation also occurs as part of natural plant processes. Exposure of live pollen to water, or even high humidity triggers osmotic shock and subsequent pollen rupture and release of cytoplasmic debris. Release of paucimicron and submicron aerosols follows this rupture under special circumstances that have been identified by inducing rupture in controlled laboratory experiments. Evidence that these processes occur naturally is provided by observations of pollen allergen proteins in fine (respirable) fractions of the atmospheric aerosol, and of ruptured pollen in atmospheric samples. The rele...
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Thunderstorms have often been linked to epidemics of asthma, especially during the grass flowering season; however, the precise mechanisms explaining this phenomenon are unknown. Evidence of high respirable allergen loadings in the air... more
Thunderstorms have often been linked to epidemics of asthma, especially during the grass flowering season; however, the precise mechanisms explaining this phenomenon are unknown. Evidence of high respirable allergen loadings in the air associated with specific meteorologic events combined with an analysis of pollen physiology suggests that rupture of airborne pollen can occur. Strong downdrafts and dry, cold outflows distinguish thunderstorm rain from frontal rain. The weather system of a mature thunderstorm likely entrains grass pollen into the cloud base, where pollen rupture would be enhanced, then transports the respirable-sized fragments of pollen debris to ground level where outflows distribute them ahead of the rain. The conditions occurring at the onset of a thunderstorm might expose susceptible people to a rapid increase in concentrations of pollen allergens in the air that can readily deposit in the lower airways and initiate asthmatic reactions.
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... Asthma and Glovsky Center, Huntington Medical Research Institute (Dr. Glovsky), Pasadena, CA; and Department of Pathophysiology (Dr. Valenta), University of ... PhD; Michelle V. Fanucchi, PhD; Michael J. Evans, PhD; Joan E. Gerriets,... more
... Asthma and Glovsky Center, Huntington Medical Research Institute (Dr. Glovsky), Pasadena, CA; and Department of Pathophysiology (Dr. Valenta), University of ... PhD; Michelle V. Fanucchi, PhD; Michael J. Evans, PhD; Joan E. Gerriets, PhD; Lei F. Putney, MS; Mary Y. Stovall ...
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Asthma is a significant global public health issue. Severe asthma exacerbations can be triggered by environmental factors and require medical care from health services. Although it is known that fungal exposure may lead to allergic... more
Asthma is a significant global public health issue. Severe asthma exacerbations can be triggered by environmental factors and require medical care from health services. Although it is known that fungal exposure may lead to allergic sensitization, little is understood about its impact on asthma exacerbations. This review aims to examine whether outdoor fungi play a significant role in child asthma exacerbations. Systematic search of seven electronic databases and hand searching for peer-reviewed studies published in English, up to 31 August 2013. Inclusion criteria were study population aged <18 yr, diagnosis of asthma, attended a health service; outdoor fungi exposure was reported. Quality and risk of bias assessments were conducted. Due to significant heterogeneity, meta-analysis was not conducted. Of the 1896 articles found, 15 were eligible. Findings were not consistent, possibly due to methodological variations in exposure classifications, statistical methods and inclusion of confounders. Cross-sectional studies found no or weak associations. All but one time series studies indicated an association that varied between fungal species. Increasing evidence indicates that asthmatic children are susceptible to asthma exacerbations when exposed to outdoor fungal spores. There is limited understanding of the contributions of different fungal species. Research is needed to investigate interactions of outdoor fungi with pollen, air pollutants and respiratory viruses.
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The sperm cells of Rhododendron laetum and R. macgregoriae differentiate within the pollen tube about 24 h after germination in vitro. Threedimensional reconstruction shows that the sperm cells are paired together, and both have... more
The sperm cells of Rhododendron laetum and R. macgregoriae differentiate within the pollen tube about 24 h after germination in vitro. Threedimensional reconstruction shows that the sperm cells are paired together, and both have extensions that link with the tube nucleus, forming a male germ unit. Quantitative analysis shows that the sperm cells in each pair differ significantly in surface
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... Biol Cell 44:315-324 Cass DD (1973) An ultrastructural and Nomarski-interference study of the sperms of barley. ... Z Pflanzenphysiol 98:365-370 Lafountain JR Jr, Zobel CR, Thomas HR,Galbreath C (1977) Fixation and staining of F-actin... more
... Biol Cell 44:315-324 Cass DD (1973) An ultrastructural and Nomarski-interference study of the sperms of barley. ... Z Pflanzenphysiol 98:365-370 Lafountain JR Jr, Zobel CR, Thomas HR,Galbreath C (1977) Fixation and staining of F-actin and microfilaments using tannic acid. ...
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Sperm cells of pollen tubes grown both in vivo and in vitro form a male germ unit. Extensions from both sperm cells of each pollen tube are closely associated with the tube nucleus. A high yield (2.7 × 104. 20 mg-1 pollen grains... more
Sperm cells of pollen tubes grown both in vivo and in vitro form a male germ unit. Extensions from both sperm cells of each pollen tube are closely associated with the tube nucleus. A high yield (2.7 × 104. 20 mg-1 pollen grains germinated) of intact sperm cells was obtained following release by osmotic shock from pollen tubes grown in
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... 10 AM Youssef, RS Farag, MA Ewies and SMA El Shakoa, Chemical studies on pollen collected by honey bees in Giza region ... 13 DE Evans, NE Rothnie, JP Sang, MV Palmer, DL Mulcahy, MBSingh and RB Knox, Correlations between gametophytic... more
... 10 AM Youssef, RS Farag, MA Ewies and SMA El Shakoa, Chemical studies on pollen collected by honey bees in Giza region ... 13 DE Evans, NE Rothnie, JP Sang, MV Palmer, DL Mulcahy, MBSingh and RB Knox, Correlations between gametophytic (pollen) and sporophytic ...
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Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 microns in diameter) to smaller size fractions < 2.5 microns (fine particles, PM25). These... more
Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 microns in diameter) to smaller size fractions < 2.5 microns (fine particles, PM25). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution. We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air. We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron-microscopic imaging technique. DECP are visualized as small carbon spheres, each 30-60 nm in diameter, forming fractal aggregates about 1-2 microns in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p 1, binds to one defined class of fine particles, DECP. DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p 1 under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.
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Research Interests: Climate Change, Atmospheric Science, Climatology, Meteorology, Multidisciplinary, and 15 moreMass, Forests, Gas Chromatography, Relative Humidity, Biomass burning, Geophysical, Fatty Acid, Night, Organic carbon, Mass Spectroscopy, Wind Speed, Diameter, Organic Compound, Temporal Variability, and Organic aerosol
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Understanding the impact on human health during peak episodes in air pollution is invaluable for policymakers. Particles less than PM2.5 can penetrate the respiratory system, causing cardiopulmonary and other systemic diseases.... more
Understanding the impact on human health during peak episodes in air pollution is invaluable for policymakers. Particles less than PM2.5 can penetrate the respiratory system, causing cardiopulmonary and other systemic diseases. Statistical regression models are usually used to assess air pollution impacts on human health. However, when there are databases missing, linear statistical regression may not process well and alternative data processing should be considered. Nonlinear Artificial Neural Networks (ANN) are not employed to research environmental health pollution even though another advantage in using ANN is that the output data can be expressed as the number of hospital admissions. This research applied ANN to assess the impact of air pollution on human health. Three well-known ANN were tested: Multilayer Perceptron (MLP), Extreme Learning Machines (ELM) and Echo State Networks (ESN), to assess the influence of PM2.5, temperature, and relative humidity on hospital admissions d...
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... Philip E. Taylor 1, Kerstin Spuck 2, Penelope M. Smith 1, Jenneth M. Sasse 1., Takao Yokota 3, Peter G. Gritfiths 2, and Donald W. Cameron 2 School of Botany and 2 ... 1990; Abe 1991), and bioassay data indicate their presence in an... more
... Philip E. Taylor 1, Kerstin Spuck 2, Penelope M. Smith 1, Jenneth M. Sasse 1., Takao Yokota 3, Peter G. Gritfiths 2, and Donald W. Cameron 2 School of Botany and 2 ... 1990; Abe 1991), and bioassay data indicate their presence in an even wider range of plants (Mandava 1988). ...
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Research Interests: Plant Biology, Fertility, Gene expression, Arabidopsis thaliana, Sexual Plant Reproduction, and 14 moreMeiosis, Mutation, Glucuronidase, Male Fertility, Structure Analysis, Arabidopsis, Affective interaction, Degeneration, Male Sterility, PLANT PROTEINS, Female Fertility, Planta, Vegetative Growth, and Genetic control
Abstract Allergenic proteins present in pollen grains, when inhaled, interact with the airways to cause an attack of asthma in susceptible humans. In one system, grass pollen grains rupture osmotically in rainfall, releasing... more
Abstract Allergenic proteins present in pollen grains, when inhaled, interact with the airways to cause an attack of asthma in susceptible humans. In one system, grass pollen grains rupture osmotically in rainfall, releasing allergen-containing inhalable particles into the ...
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We have identified a major allergenic protein from rye-grass pollen, tentatively designated Lol pIb of 31kDa and with pI 9.0. A cDNA clone encoding Lol pIb has been isolated, sequenced, and characterized. Lol pIb is located mainly in the... more
We have identified a major allergenic protein from rye-grass pollen, tentatively designated Lol pIb of 31kDa and with pI 9.0. A cDNA clone encoding Lol pIb has been isolated, sequenced, and characterized. Lol pIb is located mainly in the starch granules. This is a distinct allergen from Lol pI, which is located in the cytosol. Lol pIb is synthesized in pollen as a pre-allergen with a transit peptide targeting the allergen to amyloplasts. Epitope mapping of the fusion protein localized the IgE binding determinant in the C-terminal domain.
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Lipid accumulation during pollen and tapetal development was studied using cryostat sections of unfixed anthers from Brassica napus (rapeseed). Diamidino-2-henylindole (DAPI), a DNA fluorochrome, was used to stain the pollen nuclei in... more
Lipid accumulation during pollen and tapetal development was studied using cryostat sections of unfixed anthers from Brassica napus (rapeseed). Diamidino-2-henylindole (DAPI), a DNA fluorochrome, was used to stain the pollen nuclei in order to identify ten stages of pollen development in Brassica. Storage lipids (i.e. triacylglycerides) were stained using the fluorochrome Nile red. Pollen coat lipids are formed in tapetal plastids between the mid-vacuolate and early maturation pollen stages. The pollen coat components, including lipids and a proportion of the proteins, are derived from the remnants of the tapetum, after its rupture, during the second pollen mitosis. Quantitative microfluorometric analyses demonstrated four phases of lipid body accumulation or depletion in the developing pollen cytoplasm. The majority of storage lipids found in the cytoplasm of the mature pollen grain accumulated during the late vacuolate and early maturation stages when the pollen is bicellular. The level of acyl carrier protein, a protein integrally involved in lipid synthesis, was also found to be maximal in the developing pollen during the bicellular pollen stages of development. This coincided with the most active period of lipid accumulation. These data could indicate that the lipids of the pollen are synthesized in situ, by metabolic processes regulated by expression of genes in the haploid genome.