章节大纲

    • It was found that treatment of Neopyropia yezoensis gametophyte with 1-aminocyclopropanecarboxylic acid (ACC), a precursor of ethylene that is one of the plant hormones in land plants, promotes sexual reproduction. On the other hand, when the same experiment was conducted with ethephon, which is an ethylene generator, the promotion of sexual reproduction, observed with ACC treatment, was absent. Therefore, it was clarified that ethylene, which is known to control fruit maturation, does not act on Neopyropia yezoensis, and its precursor acts as a plant hormone.


    • In addition, ACC treatment was shown to promote the synthesis of ascorbic acid (vitamin C), which increases oxidative stress tolerance. By culturing ACC-untreated algae in a medium containing hydrogen peroxide (H2O2), oxidative stress causes the pigment to disappear and cells die (left), while ACC-treated algae can survive (right). We believe that this mechanism protects the photosynthetic device from oxidative stress, such as high water-temperature and long-day conditions found in the environment in early spring when Neopyropia yezoensis matures.