Studies on Ultrastructure and Function of Photosynthetic Apparatus in Rice Cells : III. Photooxidative damages of chloroplasts in rice seedlings

Japanese Journal of Crop Science

Sachiko HIBI¹  Susumu TOYAMA¹ 

关键词: Carotenoid;    イネの幼植物;    Chlorophyll;    カロチノイド;    Chloroplast;    クロロフィル;    Oryza sativa;    光酸化;    Photooxidation;    チラコイド;    Plastoglobule;    プラスト顆粒;    Thylakoid membrane;    葉緑体;   

DOI  :  10.1626/jcs.57.225

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

Studies on the photooxidation of chloroplasts have been performed using carotenoid-deficient seedlings induced by the treatment with herbicides. The present study was made in association with the changes caused in the photosynthetic pigment content and ultrastructure when the chloroplasts in normal rice seedlings were subjected to photooxidation. When the seedlings grown under 16.2W/m2 at 23°C were continuously exposed to the light intensity of 162 W/m2 at 23°C, the chlorophyll content went on decreasing. The carotenoid content, however, did not show a significant change. Under the cycle of light and dark, the photooxidative destruction of chlorophyll went on decreasing with passage of the cycle, but no photooxidation was observed during the third cycle. On the other hand, the photooxidative damages of chloroplast structure were observed by electron microscopy. The appearance of RuBP Case crystal, the swelling of thylakoid membranes and the formation of plastoglobules were characteristic alterations. Especially, the electron density of grana thylakoids increased abnormally according to the lysis and release of membrane components. It appeared that the released materials transferred among the thylakoid interspaces to form the plastoglobules. When the seedlings were exposed to the sun light in the field, grana thylakoids were injured and plastoglobules become temporally prominent. However, the chloroplasts seemed to be recovered from the injury in the night.

【 授权许可】

Unknown