Institut für Allgemeine Botanik, der Universität Hamburg, Jungiusstr. 6, D-2, Hamburg 36, Federal Republic of Germany.
Planta. 1974 Jan;121(3):253-61. doi: 10.1007/BF00389325.
The influence of several natural and synthetic hormones on apical dominance of pea roots was investigated. Extracts of roots decapitated just before extraction or 12 h earlier were compared in a lateral root formation assay, in the Amaranthus assay for cytokinins and the Avena coleoptile assay. Indole-3-acetic acid shows a strong promotive effect on the initiation of lateral roots. Gibberellic acid has no significant effect. Abscisic acid and its presumable precursor xanthoxin show a strong inhibitory effect, and so do all cytokinins investigated (kinetin, benzyladenine, and zeatin). Decapitation of roots caused a significant increase in the number of lateral root primordia within 12 h. Paper chromatograms of root extracts indicate the presence of at least two inhibitors of lateral root formation in the alkaline fraction, and of two promoters in the acid fraction. The amount of both inhibitors seems to decrease if the tip of the main root is removed 12 h before extraction whereas the promoters of lateral root formation do not change in their concentration. The Amaranthus test shows cytokinin activity in the region of one of the two inhibitors, and this activity decreases after decapitation. The second inhibitor has the Rf of xanthoxin; it inhibits the growth of Avena coleoptiles and its activity also decreases after decapitation.
研究了几种天然和合成激素对豌豆根顶端优势的影响。在侧根形成测定、苋菜细胞分裂素测定和燕麦胚芽鞘测定中，比较了刚提取前或提前 12 小时去顶的根提取物。吲哚-3-乙酸对侧根起始具有强烈的促进作用。赤霉素没有显著影响。脱落酸及其可能的前体黄氧素表现出强烈的抑制作用，所研究的所有细胞分裂素（激动素、苄基腺嘌呤和玉米素）也是如此。去顶根在 12 小时内导致侧根原基的数量显著增加。根提取物的纸色谱图表明，碱性部分至少存在两种侧根形成抑制剂，酸性部分存在两种促进剂。如果在提取前 12 小时去除主根的尖端，两种抑制剂的含量似乎会减少，而侧根形成的促进剂在浓度上不会改变。苋菜试验显示，在两种抑制剂之一的区域具有细胞分裂素活性，而去顶后这种活性降低。第二种抑制剂具有黄氧素的 Rf 值；它抑制燕麦胚芽鞘的生长，而去顶后其活性也降低。
