The root nodules of legumes have the ability of symbiotic nitrogen fixation, which is an environmentally friendly and efficient nitrogen use method in agricultural production.Symbiotic nitrogen fixation requires beneficial interaction between rhizobia and the plant host cells. To fix nitrogen, the plant needs to provide a low oxygen environment as bacterial nitrogenase is highly sensitive to oxygen.
First Pubulished: 2021-12-20Double fertilization is a flowering plant mechanism whereby two immotile sperm cells fertilize two different female gametes. After double fertilization, a seed consists of the embryo, the endosperm and the seed coat, which develop from the zygote, the fertilized central cell and the maternal integuments, respectively.
First Pubulished: 2021-12-20In female gametophytes, eight nuclei are separated into four cell types after three rounds of nuclear divisions without cell division. After the cellularization and nuclear fusion, they develop into a mature seven-cell embryo sac, including an egg cell(ec), a central cell(cc), two synergid cells(sc) and three antipodal cells. It’s important to ensure that all the cells in the embryo sac have normal functions, so that they are well prepared for the double fertilization. In this part,
First Pubulished: 2021-12-20In angiosperms, the fertilization between female and male gametes is unique when compares to other species. Angiosperms’ sperm cell which has no autonomous mobility needs pollen tube to be delivered to female gamete. When pollen tubes grow in pistil, there are complex communication systems between male and female to regulate pollen tubes target to female gametophytes.
First Pubulished: 2021-12-20Male gametophyte generation and development is one of the key steps of sexual reproduction in plants. The occurrence of male gametophytes includes male gamete development and specialization, the formation of microspores (including reduction cleavage), male gametophyte (pollen grains) formation. The microspore mother cell undergoes meiosis and forms four haploid microspores. Each microspore undergoes an unequal round of mitosis to produce two-celled pollen.
First Pubulished: 2021-12-20