Proteomic analysis of the stigmatic exudate of Lilium longiflorum and Olea europaea led to the identification of 51 and 57 proteins, respectively, most of which are described for the first time in ...this secreted fluid. These results indicate that the stigmatic exudate is an extracellular environment metabolically active, participating in at least 80 different biological processes and 97 molecular functions. The stigma exudate showed a markedly catabolic profile and appeared to possess the enzyme machinery necessary to degrade large polysaccharides and lipids secreted by papillae to smaller units, allowing their incorporation into the pollen tube during pollination. It may also regulate pollen-tube growth in the pistil through the selective degradation of tube-wall components. Furthermore, some secreted proteins were involved in pollen-tube adhesion and orientation, as well as in programmed cell death of the papillae cells in response to either compatible pollination or incompatible pollen rejection. Finally, the results also revealed a putative cross-talk between genetic programmes regulating stress/defence and pollination responses in the stigma.
During sexual reproduction, pollen performance is greatly influenced by the female tissues. The stigma exudate, i.e., the extracellular secretion that covers the stigma outermost surface, has been ...usually regarded as a reservoir of water, secondary metabolites, cell wall precursors and compounds that serve as energy supply for rapid pollen tube growth. In an attempt to identify the proteins present in the stigma secretome, we performed a large-scale analysis in two species (Lilium longiflorum and Olea europaea) following a proteomic-based approach. The resulting data strongly suggest that the stigma exudate is not a mere storage site but also a biochemically active environment with a markedly catabolic nature. Thus, this secretion may modulate early pollen tube growth and contribute to the senescence of stigma after pollination. In addition, a putative cross-talk between genetic programs that regulate stress/defense and pollination responses in the stigma is also suggested. The stigma exudate might also functionally diverge between species on the basis on their ecology and the biochemical, morphological and anatomical features of their stigmas. Unexpectedly, we identified in both exudates some intracellular proteins, suggesting that a mechanism other than the canonical ER-Golgi exocytic pathway may exist in the stigma and contribute to exudate secretion.
During sexual reproduction, pollen performance is greatly influenced by the female tissues. The stigma exudate, i.e., the extracellular secretion that covers the stigma outermost surface, has been ...usually regarded as a reservoir of water, secondary metabolites, cell wall precursors and compounds that serve as energy supply for rapid pollen tube growth. In an attempt to identify the proteins present in the stigma secretome, we performed a large-scale analysis in two species (Lilium longiflorum and Olea europaea) following a proteomic-based approach. The resulting data strongly suggest that the stigma exudate is not a mere storage site but also a biochemically active environment with a markedly catabolic nature. Thus, this secretion may modulate early pollen tube growth and contribute to the senescence of stigma after pollination. In addition, a putative cross-talk between genetic programs that regulate stress/defense and pollination responses in the stigma is also suggested. The stigma exudate might also functionally diverge between species on the basis on their ecology and the biochemical, morphological and anatomical features of their stigmas. Unexpectedly, we identified in both exudates some intracellular proteins, suggesting that a mechanism other than the canonical ER-Golgi exocytic pathway may exist in the stigma and contribute to exudate secretion.
Exiles from European revolutions Sabine Freitag, Rudolf Muhs / Sabine Freitag, Rudolf Muhs
2003., 20030715, 2003, 2003-07-15, 20030101
eBook
Studies on exile in the 19th century tend to be restricted to national histories. This volume is the first to offer a broader view by looking at French, Italian, Hungarian, Polish, Czech and German ...political refugees who fled to England after the European revolutions of 1848/49. The contributors examine various aspects of their lives in exile such as their opportunities for political activities, the forms of political cooperation that existed between exiles from different European countries on the one hand and with organizations and politicians in England on the other and, finally, the attitude of the host country towards the refugees, and their perceptions of the country which had granted them asylum.
The photodynamic effect of the arginine hematoporphyrin derivative (HpD-Arg(2)) on the growth of selected Pseudomonas aeruginosa clinical isolates is described as compared to the effect of ...hematoporphyrin derivative (HpD). Growth inhibition of HpD-Arg(2) of three Gram-positive strains (Staphylococcus aureus, Bacillus subtilis and Micrococcus luteus) and five laboratory strains of Gram-negative bacteria (Escherichia coli, Proteus vulgaris, P. aeruginosa, Klebsiella pneumoniae and Enterobacter cloacae) was observed as well. Serratia marcescens strain was resistant to light-activated HpD-Arg(2) or HpD. The antimicrobial activity of light-activated HpD-Arg(2) against P. aeruginosa may offer an additional option in the anti-pseudomonal therapy of wounds.
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