pollenkornrør
Pollenkornrør, often translated as pollen tube, is a crucial structure in the reproduction of seed plants. Following pollination, when a pollen grain lands on the receptive surface of a stigma, it germinates. This germination involves the growth of a tube-like extension from the pollen grain, which penetrates the stigma and style. The pollen tube serves as a conduit, carrying the male gametes (sperm cells) from the pollen grain down towards the ovule, which contains the female gamete (egg cell). The journey of the pollen tube through the tissues of the pistil can be quite extensive, depending on the plant species. Once it reaches the ovule, usually through a small opening called the micropyle, the male gametes are released. This enables fertilization, the fusion of the male and female gametes, which is essential for the development of a seed. The formation and growth of the pollen tube are complex processes regulated by chemical signals exchanged between the pollen grain and the pistil. This intricate mechanism ensures that successful fertilization occurs, leading to the continuation of the plant species.