Stable oil bodies were purified from mature lily (Lilium longiflorum Thunb.) pollen. The integrity of pollen oil bodies was maintained via electronegative repulsion and steric hindrance possibly provided by their surface proteins. Immunodetection revealed that a major protein of 18 kDa was exclusively present in pollen oil bodies and massively accumulated in late stages of pollen maturation. Ac...

Members of the ubiquitous COX11 (cytochrome c oxidase 11) protein family are involved in copper delivery to the COX complex. In this work, we characterize the Arabidopsis thaliana COX11 homolog (encoded by locus At1g02410). Western blot analyses and confocal microscopy identified Arabidopsis COX11 as an integral mitochondrial protein. Despite sharing high sequence and structural similarities, t...

The exocyst, a complex of eight proteins, contributes to the morphogenesis of polarized cells in a broad range of eukaryotes. In these organisms, the exocyst appears to facilitate vesicle docking at the plasma membrane during exocytosis. Although we had identified orthologs for each of the eight exocyst components in Arabidopsis (Arabidopsis thaliana), no function has been demonstrated for any ...

The effects of temperature on pollen germination and pollen tube growth rate were measured in vitro in thermogenic skunk cabbage, Symplocarpus renifolius Schott ex Tzvelev, and related to floral temperatures in the field. This species has physiologically thermoregulatory spadices that maintain temperatures near 23 degrees C, even in sub-freezing air. Tests at 8, 13, 18, 23, 28 and 33 degrees C ...

Ion signals are critical to regulating polarized growth in many cell types, including pollen in plants and neurons in animals. Genetic evidence presented here indicates that pollen tube growth requires cyclic nucleotide-gated channel (CNGC) 18. CNGCs are nonspecific cation channels found in plants and animals and have well established functions in excitatory signal transduction events in animal...

BACKGROUND AND AIMS Stigmatic receptivity plays a clear role in pollination dynamics; however, little is known about the factors that confer to a stigma the competence to be receptive for the germination of pollen grains. In this work, a developmental approach is used to evaluate the acquisition of stigmatic receptivity and its relationship with a possible change in arabinogalactan-proteins (AG...

SHY, a pollen-specific gene identified in a screen for genes upregulated at pollen germination, encodes a leucine-rich repeat (LRR) protein that is predicted to be secreted. To test if SHY plays an important role during pollen germination, we generated transgenic plants expressing an antisense (AS) copy of the SHY cDNA in pollen. Primary transformants exhibited poor seed set, but homozygous lin...

Silene alba, a perennial, dioecious plant, produces flowers that open in the evening and can remain open and receptive to pollination for up to 5 d, though in hot and dry conditions the flowers will wilt during the day only to reopen night after night. In the field, it is visited by two different kinds of pollinators with differential success: moths visit the flowers at night, and their movemen...

Sexual conflict and its evolutionary consequences are understudied in plants, but the theory of sexual conflict may help explain how selection generates and maintains variability. Here, we investigated selection on pollen and pistil traits when pollen arrives sequentially to partially receptive pistils in relation to pollen competition and a sexual conflict over timing of stigma receptivity in ...

Temperature integration where high day temperatures are compensated by lower night temperatures is one strategy that can be used to reduce energy consumption in greenhouses. Crop tolerance to temperature variation is a prerequisite for using such a strategy. Greenhouse experiments were conducted on tomatoes cvs, Capricia, Mecano and Cederico in order to investigate the effect of different day/n...