Ching T M
Seed Laboratory, Oregon State University, Corvallis, Oregon 97331.
Plant Physiol. 1970 Sep;46(3):475-82. doi: 10.1104/pp.46.3.475.
Decoated ponderosa pine (Pinus ponderosa Laws) seeds contained 40% lipids, which were mainly stored in megagametophytic tissue and were utilized or converted to sugars via the glyoxylate cycle during germination. Mitochondria and glyoxysomes were isolated from the tissue by sucrose density gradient centrifugation at different stages of germination. It was found that isocitrate lyase, malate synthase, and catalase were mainly bound in glyoxysomes. Aconitase and fumarase were chiefly localized in mitochondria, whereas citrate synthase was common for both. Both organelles increased in quantity and specific activity of their respective marker enzymes with the advancement of germination. When the megagametophyte was exhausted at the end of germination, the quantity of these organelles and the activity of their marker enzymes decreased abruptly. At the stage of highest lipolysis, the isolated mitochondria and glyoxysomes were able to synthesize protein from labeled amino acids. Both organellar fractions contained RNA and DNA. Some degree of autonomy in glyoxysomes is indicated.
去壳的黄松（Pinus ponderosa Laws）种子含有40%的脂质，这些脂质主要储存在雌配子体组织中，并在萌发过程中通过乙醛酸循环被利用或转化为糖类。在萌发的不同阶段，通过蔗糖密度梯度离心从组织中分离出线粒体和乙醛酸循环体。发现异柠檬酸裂解酶、苹果酸合酶和过氧化氢酶主要结合在乙醛酸循环体中。乌头酸酶和延胡索酸酶主要定位于线粒体，而柠檬酸合酶在两者中都有。随着萌发的进行，这两种细胞器各自标记酶的数量和比活性都增加。当萌发结束时雌配子体耗尽时，这些细胞器的数量及其标记酶的活性急剧下降。在最高脂解阶段，分离出的线粒体和乙醛酸循环体能够从标记的氨基酸合成蛋白质。两个细胞器部分都含有RNA和DNA。这表明乙醛酸循环体具有一定程度的自主性。
