Using a newly developed vibrating electrode, we have explored the electric fields around lily pollen germinating in vitro. From these field measurements, we infer that each weeted pollen drives a steady current of a few hundred picoamperes through itself. Considered as a flow of positive ions, this current enters an ungerminated grain's prospective growth site and leaves it opposite end. Aft...

Pollination in flowering plants begins when pollen lands on a stigma. The process continues as the pollen germinates and grows through intercellular spaces in the pistil, and it culminates when the pollen reaches the ovary and fertilization occurs. This complex and hazardous process involves many interactions, including cell–cell recognition and intracellular and intercellular signaling, as wel...

In double fertilization, the vegetative cell of the male gametophyte (pollen) germinates and forms a pollen tube that brings to the female gametophyte two sperm cells that fertilize the egg and central cell to form the embryo and endosperm, respectively. The 5-methylcytosine DNA glycosylase DEMETER (DME), expressed in the central cell, is required for maternal allele demethylation and gene impr...

Plant sexual reproduction depends on highly specific interactions between pollen and pistil, the male gametophyte and the female reproductive organ, respectively (1, 2). The pistil is composed of three major structural parts: the stigma, the style, and the ovary. The stigma has a pollen-receptive surface and several underlying secretory cell layers. The style connects the stigma to the basally ...

One premise of the biological species concept (BSC) is that reproductive barriers act to prevent interbreeding between species. While the BSC is not universally applicable, interspecifi c reproductive barriers (IRBs) between species can be detected in many cases. For example, in the tomato clade ( Solanum sect. Lycopersicon ) prezygotic IRBs can prevent hybridization between certain species ( R...

INTRODUCTION ' The extremely reduced, three-celled, haploid male plant (male gametophyte) of flowering plants has a number of specialized functions to perform. The primary functions are the production of two sperm cells and their transport within the pollen tube through the tissues of the style and ovary into the embryo sac in the ovule, where they participate in double fertilization. The early...

Mature pollen from most plant species is metabolically quiescent; however, after pollination, it germinates quickly and gives rise to a pollen tube to transport sperms into the embryo sac. Because methods for collecting a large amount of in vitro germinated pollen grains for transcriptomics and proteomics studies from model plants of Arabidopsis and rice are not available, molecular information...

the importance of amaranthus retroflexus pollen in causing respiratory allergy has been well ascertained in many countries including iran with a high positive rate (69%) among iranian allergic patients. the aim of the present study is to identify the allergenic properties of a. retroflexus pollen. sixteen patients with allergy to a. retroflexus pollen were selected for the study. the antigenic ...

Pollen hydration is usually tightly regulated and occurs in vivo only when desiccated pollen grains acquire water from the female, thus enabling pollen tube growth. Pollen tubes are easily visualized by staining with decolorized aniline blue, a stain specific for callose. We identified a mutant, raring-to-go, in which pollen grains stained for callose before anther dehiscence. When raring-to-go...