Forest Service, U.S. Department of Agriculture, North Central Forest Experiment Station, Institute of Forest Genetics, Rhinelander, Wisconsin.
Planta. 1970 Mar;95(1):27-35. doi: 10.1007/BF00431118.
Removal of the stem apex and certain leaves and axillary buds of brittle willows (Salix fragilis) was employed to limit the supply of endogenous auxin to adventitious root primordia during their formation, which occurs at predetermined sites. Limiting endogenous auxin by this surgical treatment resulted in reduced primordium initiation and, to a lesser degree, primordium growth in cell number. Root primordium cells in surgically treated plants differentiated into mature parenchyma after losing their meristematic character. Application of indole-3-acetic acid (IAA) to surgically treated plants partially overcame the effects of the surgical tretament, increasing root primordium initiation and growth by cell division. When IAA-2-(14)C was applied to surgically treated plants, label was detected in root primordium cells by means of autoradiography. Root primordium cells took up more label during the earliest stage of initiation than during a later stage of growth. The data indicate that the initiation of these primordia is more dependent on a supply of auxin than is their subsequent development. Further, the auxin apparently acts directly in the cells which initiate primordia.
去除脆性柳树（Salix fragilis）的茎尖和某些叶子和腋芽，以限制在其预定部位形成不定根原基时内源生长素的供应。通过这种手术处理限制内源生长素会导致原基起始减少，在较小程度上导致原基细胞数量生长减少。在手术处理的植物中，根原基细胞在失去分生组织特征后分化为成熟的薄壁组织。将吲哚-3-乙酸（IAA）施用于手术处理的植物部分克服了手术处理的影响，通过细胞分裂增加了根原基的起始和生长。当将 IAA-2-（14）C 施用于手术处理的植物时，通过放射自显影术在根原基细胞中检测到标记。在起始的最早阶段，根原基细胞吸收的标记比在生长的后期阶段更多。这些数据表明，这些原基的起始比随后的发育更依赖于生长素的供应。此外，生长素显然直接作用于起始原基的细胞。
