BACKGROUND Actin is essential for tip growth in plants. However, imaging actin in live plant cells has heretofore presented challenges. In previous studies, fluorescent probes derived from actin-binding proteins often alter growth, cause actin bundling and fail to resolve actin microfilaments. METHODOLOGY/PRINCIPAL FINDINGS In this report we use Lifeact-mEGFP, an actin probe that does not aff...

Pollen tubes of higher plants grow very rapidly until they reach the ovules to fertilize female gametes. This growth process is energy demanding, however, nutrition strategies pollen are largely unexplored. Here, we studied function sucrose transporters and invertases during germination tube growth. RT-PCR analyses, reporter lines knockout mutants were used study gene expression protein in poll...

Large scale phenotyping of tip growing cells such as pollen tubes has hitherto been limited to very crude parameters such as germination percentage and velocity of growth. To enable efficient execution of more sophisticated assays, an experimental platform was developed based on microfluidic and MEMS technology, the TipChip. The device allows positioning of pollen grains or fungal spores at the...

Some Malpighiaceae produce minute cleistogamous flowers in addition to showy chasmogamous flowers. Standard techniques fail to reveal how the cleistogamous flowers achieve self-fertilization. Fluorescence in longitudinal sections shows that the pollen germinates inside the indehiscent anther. The pollen tubes then grow down through the filament,. into the receptacle, up into the carpels, and in...

The flowering plant pollen tube is the fastest elongating plant cell and transports the sperm cells for double fertilization. The highly dynamic formation and reorganization of the actin cytoskeleton is essential for pollen germination and pollen tube growth. To drive pollen-specific expression of fluorescent marker proteins, commonly the strong Lat52 promoter is used. Here we show by quantitat...

Sucrose synthase (Sus; EC 2.4.1.13) is a key enzyme of sucrose metabolism in plant cells, providing carbon for respiration and for the synthesis of cell wall polymers and starch. Since Sus is important for plant cell growth, insights into its structure, localization, and features are useful for defining the relationships between nutrients, growth, and cell morphogenesis. We used the pollen tube...

The apical plasma membrane of pollen tubes contains different PI4P 5-kinases that all produce phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P(2)] but exert distinct cellular effects. In the present example, overexpression of Arabidopsis AtPIP5K5 or tobacco NtPIP5K6-1 caused growth defects previously attributed to increased pectin secretion. In contrast, overexpression of Arabidopsis AtPIP5K...

The two sperm cells of common origin within the pollen tube of flowering plants are each involved in a fertilization event. It has long been recognized that preferential fusion of one sperm with the egg can occur in B chromosome-containing lines of maize. If the second pollen mitosis begins with a single B chromosome, nondisjunction will result in one sperm possessing two B chromosomes and the ...

In Trimenia moorei, an extant member of the ancient angiosperm clade Austrobaileyales, we found a remarkable pattern of female gametophyte (egg-producing structure) development that strikingly resembles that of pollen tubes and their intrasexual competition within the maternal pollen tube transmitting tissues of most flowers. In contrast with most other flowering plants, in Trimenia, multiple f...

Pollen-tube growth not only represents an essential stage of plant reproduction but also provides an attractive model for studying cell polarity and morphogenesis. For many years, pollen-tube growth has been known to require a tip-focused Ca2+ gradient and dynamic F actin, but the way that these are controlled remained a mystery until recently. Rop appears to be activated at growth sites by a t...