The apical wall of growing pollen tubes must be strong enough to withstand the internal turgor pressure, but plastic enough to allow the incorporation of new membrane and cell wall material to support polarized tip growth. These essential rheological properties appear to be controlled by pectins, which constitute the principal component of the apical cell wall. Pectins are secreted as methylest...

Climate change and air pollution, including ozone is known to affect plants and might also influence the ragweed pollen, known to carry strong allergens. We compared the transcriptome of ragweed pollen produced under ambient and elevated ozone by 454-sequencing. An enzyme-linked immunosorbent assay (ELISA) was carried out for the major ragweed allergen Amb a 1. Pollen surface was examined by sc...

The common green bottle fly Lucilia sericata (Meigen) and other filth flies frequently visit pollen-rich composite flowers such as the Oxeye daisy, Leucanthemum vulgare Lam. In laboratory experiments with L. sericata, we investigated the effect of generic floral scent and color cues, and of Oxeye daisy-specific cues, on foraging decisions by recently eclosed flies. We also tested the effect of ...

BACKGROUND Previous transcriptome profiling studies have investigated the molecular mechanisms of pollen and anther development, and identified many genes involved in these processes. However, only 51 anther ESTs of Upland cotton (Gossypium hirsutum) were found in NCBI and there have been no reports of transcriptome profiling analyzing anther development in Upland cotton, a major fiber crop in ...

As a strategy for the identification of T-DNA-tagged gametophytic mutants, we have used T-DNA insertional mutagenesis based on screening for distorted segregation ratios by antibiotic selection. Screening of approximately 1000 transgenic Arabidopsis families led to the isolation of eight lines showing reproducible segregation ratios of approximately 1:1, suggesting that these lines are putative...

Cell wall pectins are some of the most complex biopolymers known, and yet their functions remain largely mysterious. The aim of this paper was to deepen the study of the spatial pattern of pectin distribution in the aperture of Oenothera hookeri.velans ster/+ster fertile pollen. We used "in situ" immunocytochemical techniques at electron microscopy, involving monoclonal antibodies JIM5 and JIM7...

BACKGROUND AND AIMS The dwarf eelgrass, Zostera noltii, is a predominant inhabitant of soft-bottom intertidal regions along the coasts of northern Europe. It is a monoecious, protogynous angiosperm in which the potential for self-fertilization and inbreeding are high, especially if clone sizes exceed pollen dispersal distances. The aim of the present study was to determine the relationship betw...

The dominant allergenic components of grass pollen are known by immunologists as group 1 allergens. These constitute a set of closely related proteins from the beta-expansin family and have been shown to have cell wall-loosening activity. Group 1 allergens may facilitate the penetration of pollen tubes through the grass stigma and style. In maize (Zea mays), group 1 allergens are divided into t...

In contrast to animals and lower plant species, sperm cells of flowering plants are non-motile and are transported to the female gametes via the pollen tube, i.e. the male gametophyte. Upon arrival at the female gametophyte two sperm cells are discharged into the receptive synergid cell to execute double fertilization. The first players involved in inter-gametophyte signaling to attract pollen ...

In anthers, the tapetum synthesizes and stores proteins and flavonoids, which will be transferred to the surface of adjacent microspores. The mechanism of synthesis, storage, and transfer of these pollen-coat materials in maize (Zea mays) differs completely from that reported in Arabidopsis (Arabidopsis thaliana), which stores major pollen-coat materials in tapetosomes and elaioplasts. On maize...