Pollen tube growth is dependent on a dynamic actin cytoskeleton, suggesting that actin-regulating proteins are involved. We have examined the regulation of the lily pollen-specific actin-depolymerizing factor (ADF) LlADF1. Its actin binding and depolymerizing activity is pH sensitive, inhibited by certain phosphoinositides, but not controlled by phosphorylation. Compared with its F-actin bindin...

Pollen grains from grasses using the C3 and C4 photosynthetic pathways have distinct ranges of d C values that may be used to estimate their relative abundance in paleorecords. We evaluated a spooling-wire microcombustion device interfaced with an isotope-ratio mass spectrometer (SWiM-IRMS) for dC analysis of individual grass-pollen grains. Pollen from four C3 and four C4 grass species was isol...

Lung surfactant protein A (SP-A) is the most abundant surfactant-associated protein present in the lung. A receptor for SP-A has been shown to be present on A549 alveolar type II cells and on other cell types, including alveolar macrophage. The SP-A receptor on A549 cells has been identified as the collection receptor, or C1q receptor, which binds several structurally-related ligands. SP-A cont...

The analysis of pollen grains taken from core samples is an extremely valuable technique for climate reconstruction. There is a great need for an automated classification system which can provide a swift and accurate analysis of the relative amounts of pollen on a microscope slide. Pollen grains have a complex three-dimensional structure and can appear on the microscope slide in any orientation...

The objective of this study was to determine the effect of application of pesticides on morphology, viability, and germination of pollen grains of Blackberry (Rubus glaucus Benth.) and Tree tomato (Solanum betaceum Cav.). The study was performed at Patate, Tungurahua province, Ecuador and was divided into two phases. Phase one dedicated to the study of morphology, viability, and identification ...

The mean diameter of viable pollen grains is approximately 13 μm greater than the mean diameter of inviable grains in Mimulus guttatus. We show that this difference is large enough to be detected by particle counters and that these machines can be used to obtain a rapid estimate of pollen viability. While requiring a separate calibration, a size-based statistic is also strongly correlated with ...

The pollen morphology and exine structure of 17 species of Lippia L. were investigated in this work using light and scanning electron microscopy. Among the species studied, 14 showed tricolporate pollen grains, two had tri- and tetracolporate pollen grains and a single species exhibited, only tetracolporate pollen. The amb ranged from triangular to square, and the shape varied from oblate-spher...

The forests of north-eastern Croatia, as well as various plants and trees in the parks and streets of the Osijek-Baranja County, produce large amounts of pollen during the pollen season, which can cause allergy symptoms in pollen sensitive individuals. The aim of this study was to determine the most frequent types of pollen in this area and estimate possible health risks, especially the risk of...

BACKGROUND Peltophorum pterocarpum and Delonix regia are dominant avenue trees in the city of Kolkata in India. They are well adapted to the humid tropical climate and also grow commonly in different parts of the country. Their pollen grains are reported to be airborne. OBJECTIVE The aim of this study was to conduct an aerobiological survey in Kolkata to determine the concentration and season...