Department of Botany and Plant Pathology and Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907.
Plant Physiol. 1976 Oct;58(4):544-7. doi: 10.1104/pp.58.4.544.
Ultrastructural changes in isolated and in situ plasma membranes of etiolated soybean hypocotyls (Glycine max L. cv. Wayne) were induced by indole-3-acetic acid (IAA), other auxins, and calcium chloride. Fixed and embedded preparations were stained by a phosphotungstate-chromate procedure to identify and accentuate plasma membrane. Measurements were on micrographs obtained with an electron optical system calibrated and corrected for reproducible and accurate size measurements. Plasma membranes treated for 20 minutes with 1 mum IAA were 10 to 15% thinner than controls. The response to IAA was rapid, reproducible, auxin-specific, temperature-dependent, and reversible. Comparable responses were obtained with isolated and in situ membranes. Membranes treated with 0.5 m calcium chloride for 20 minutes were 15 to 20% thicker than controls. Multiple cycles of alternating calcium and IAA treatments yielded membranes with dimensions that reflected the last treatment of the series. The findings show a direct response of plasma membranes to growth regulating agents and provide evidence for a cell-free response of isolated plasma membranes to a hormone.
吲哚乙酸（IAA）、其他生长素和氯化钙诱导黄化大豆下胚轴（Glycine max L. cv. Wayne）分离和原位质膜的超微结构发生变化。固定和包埋的制剂用磷钨酸盐-重铬酸盐程序进行染色，以识别和突出质膜。测量是在经过校准和校正以进行可重复和准确尺寸测量的电子光学系统获得的显微照片上进行的。用 1 µm IAA 处理 20 分钟的质膜比对照薄 10%至 15%。对 IAA 的反应迅速、可重复、生长素特异性、温度依赖性和可逆。在分离和原位质膜中也获得了类似的反应。用 0.5 m 氯化钙处理 20 分钟的质膜比对照厚 15%至 20%。交替钙和 IAA 处理的多个循环产生的质膜尺寸反映了该系列的最后一次处理。这些发现表明质膜对生长调节剂有直接反应，并为分离质膜对激素的无细胞反应提供了证据。
