Momonoki Y S
Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824-1312, USA.
Plant Physiol. 1988;87(3):751-6. doi: 10.1104/pp.87.3.751.
Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport of [3H]-5-indole-3-acetyl-myo-inositol and [U-14C]-D-glucose from the kernel to the seedling shoot was studied. Both labeled glucose and labeled indole-3-acetyl-myo-inositol become asymmetrically distributed in the mesocotyl cortex of the shoot with more radioactivity occurring in the bottom half of a horizontally placed seedling. Asymmetric distribution of [3H]indole-3-acetic acid, derived from the applied [3H]indole-3-acetyl-myo-inositol, occurred more rapidly than distribution of total 3H-radioactivity. These findings demonstrate that the gravitational stimulus can induce an asymmetric distribution of substances being transported from kernel to shoot. They also indicate that, in addition to the transport asymmetry, gravity affects the steady state amount of indole-3-acetic acid derived from indole-3-acetyl-myo-inositol.
吲哚 - 3 - 乙酰 - 肌醇存在于发芽玉米幼苗的胚乳和营养芽中。研究了重力刺激对[3H] - 5 - 吲哚 - 3 - 乙酰 - 肌醇和[U - 14C] - D - 葡萄糖从胚乳向幼苗芽运输的影响。标记的葡萄糖和标记的吲哚 - 3 - 乙酰 - 肌醇在芽的中胚轴皮层中不对称分布，在水平放置的幼苗下半部分放射性更强。由施加的[3H] - 吲哚 - 3 - 乙酰 - 肌醇衍生的[3H]吲哚 - 3 - 乙酸的不对称分布比总3H放射性的分布更快。这些发现表明重力刺激可诱导从胚乳向芽运输的物质产生不对称分布。它们还表明，除了运输不对称外，重力还影响由吲哚 - 3 - 乙酰 - 肌醇衍生的吲哚 - 3 - 乙酸的稳态量。
