著者

Mizuta Hiroyuki Yasui Hajime

出版者

Walter de Gruyter

雑誌

Botanica Marina (ISSN:00068055)

巻号頁・発行日

vol.53, no.5, pp.409-416, 2010-10

被引用文献数

1 14

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We investigated production of radical oxygen species (ROS) in sorus development of sporophyte discs and during zoospore germination of Saccharina japonica (Phaeophyceae) using the fluorescent dye 2',7'-dichlorofluorescein diacetate (DCFH-DA). Quantitative analysis of ROS showed high intracellular production during the stages of zoosporangium formation when paraphyses elongated. In this stage, remarkable ROS release was observed. ROS production was also observed histologically (under a fluorescence microscope) in the elongating paraphyses and the sorus zoosporangia of the sorus. The sorus had significantly higher phenol content, anti-oxidant capacity and ROS scavenging enzyme activities (ascorbate peroxidase, catalase, glutathione reductase and superoxide dismutase) than adjacent non-sorus blade sectors. Thus, intracellular ROS scavenging mechanisms are active during ROS production in sorus formation. In contrast, iodine content was lower in the sorus than in the adjacent non-sorus tissues, suggesting the existence of an anti-oxidant defense mechanism based on iodine efflux. We demonstrated that ROS production is an important phenomenon in the reproduction of the sporophyte in S. japonica. Furthermore, ROS were also observed in the zoospore germination processes. We discuss the physiological and ecological roles of ROS production in sorus formation and zoospore germination.