Phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P(2)] occurs in the apical plasma membrane of growing pollen tubes. Because enzymes responsible for PtdIns(4,5)P(2) production at that location are uncharacterized, functions of PtdIns(4,5)P(2) in pollen tube tip growth are unresolved. Two candidate genes encoding pollen-expressed Arabidopsis thaliana phosphatidylinositol-4-phosphate 5-kinases (...

BACKGROUND AND AIMS Exposure to higher-than-optimal temperatures reduces crop yield and quality, mainly due to sensitivity of developing pollen grains. The mechanisms maintaining high pollen quality under heat-stress conditions are poorly understood. Our recently published data indicate high heat-stress-induced expression of ethylene-responsive genes in tomato pollen, indicating ethylene involv...

in vitro pollen germination and also pollen tube growth dynamics in different pollination treatments under controlled temperature, humidity and photoperiodicity were studied regarding four cultivars (‘shastomi - e - do’, ‘ebrahim - e - kalajah’, ‘sefid - e - rezaeeieh’ and ‘razi’) under self and under cross-pollination along with three superior genotypes (‘269’, ‘416’ and ‘464’) of apricot. fol...

Flowers of cultivated buckwheat (Fagopyrum esculentum Moench) often receive natural pollen loads of fewer than 10 pollen grains. The cultivated varieties also have high genetic variability. These observations raise the question of whether seed production in buckwheat is often limited by pollen delivery, and whether small increases in pollen load could result in gametophytic selection through po...

The objective of this experiment was evaluation of self-compatibility and identification, introduction and selection of late flowering genotypes as cultivars. This experiment was carried out in order to determine the best pollinator for two commercial almond cultivars, 'Shahrood 12' and 'Shahrood 21'. Applied pollinator cultivars were included pollen from 'Shahrood 21', 'Genco', 'Tuno', '5-15' ...

Woschnagg, C. 2000. The oxidative metabolism by eosinophils. Effects of allergen exposure and Interleukin-5. Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 962. 60 pp. Uppsala. ISBN 91-554-4827-5. In this thesis the oxidative metabolism by blood eosinophils from birch pollen allergic subjects was studied and compared to that by eosi...

Survival and growth of monarch larvae, Danaus plexippus (L.), after exposure to either Cry1Ab-expressing pollen from three Bacillus thuringiensis (Bt) corn (Zea mays L.) events differing in toxin expression or to the insecticide, lambda-cyhalothrin, were examined in field studies. First instars exposed to low doses ( approximately 22 grains per cm(2)) of event-176 pollen gained 18% less weight ...

More than 400 million individuals are sensitized to grass pollen allergens. Group 5 allergens represent the most potent grass pollen allergens recognized by more than 80 % of grass pollen allergic patients. The aim of our study was to reduce the allergenic activity of group 5 allergens for specific immunotherapy of grass pollen allergy. Based on B- and T-cell epitope mapping studies and on sequ...

Transcripts of the ntp303 gene accumulate abundantly throughout pollen development, whereas the protein only accumulates to detectable levels after pollen germination. In an attempt to explain the divergence in the accumulation profiles of the mRNA and the protein, we investigated the role of the untranslated regions (UTRs) in enhancing ntp303 translation during the transition from developing t...