Department of Botany, University of California, Berkeley, California 94720.
Plant Physiol. 1983 Jul;72(3):833-6. doi: 10.1104/pp.72.3.833.
Light stimulates gravitropic bending (downward growth) in roots of many cultivars of corn (Zea mays). In this work, using the cultivar Merit, we show that light stimulates protein synthesis in the root cap, with protein levels increasing 1.3 to 1.6 times that recorded for tissues maintained in continuous dark. Light enhances protein levels both in intact caps (attached to the root) and in caps in culture. Protein synthesis is optimal in cultured caps when 1 nanomolar indole-3-acetic acid is included in the culture medium. If cap tissue is illuminated and subsequently returned to the dark, in the 2-hour period following illumination protein levels decline to that observed in dark controls. It is proposed that light-stimulated protein synthesis mediates in part downward bending in roots of these cultivars of corn.
光是许多玉米（Zea mays）品种根弯曲（向下生长）的刺激因素。在这项工作中，我们使用 Merit 品种表明，光照刺激根冠中的蛋白质合成，使蛋白质水平增加 1.3 到 1.6 倍，而持续黑暗中记录的组织保持不变。光照增强了完整根冠（附着在根上）和培养中的根冠中的蛋白质水平。当培养基中包含 1 纳摩尔吲哚-3-乙酸时，培养的根冠中的蛋白质合成最佳。如果将冠组织暴露在光照下，然后返回黑暗中，在光照后 2 小时内，蛋白质水平下降到黑暗对照中观察到的水平。有人提出，光照刺激的蛋白质合成部分介导了这些玉米品种的根向下弯曲。
