Little C H, Goldsmith M H
School of Forestry, Yale University, New Haven, Connecticut 06520.
Plant Physiol. 1967 Sep;42(9):1239-45. doi: 10.1104/pp.42.9.1239.
The effect of a 180 degrees displacement from the normal vertical orientation on longitudinal growth and on the acropetal and basipetal movement of (14)C-IAA was investigated in Avena sativa L. and Zea mays L. coleoptile sections. Inversion inhibits growth in intact sections (apex not removed) and in decapitated sections supplied apically with donor blocks containing auxin. Under aerobic conditions, inversion inhibits basipetal auxin movement and promotes acropetal auxin movement, whereas under anaerobic conditions, it does not influence the movement of auxin in either direction. Inversion retards the basipetal movement of the peak of a 30-minute pulse of auxin in corn.The inversion-induced inhibition of basipetal auxin movement is not explained by an effect of gravity on production, uptake, destruction, exit from sections, retention in tissue, or purely physical movement of auxin. It is concluded that inversion (a) inhibits basipetal transport, the component of auxin movement that is metabolically dependent, and as a result (b) inhibits growth and (c) promotes acropetal auxin movement.
研究了燕麦和玉米胚芽鞘切段从正常垂直方向发生180度位移对纵向生长以及对¹⁴C - IAA向顶和向基运输的影响。倒置抑制完整切段（未去除顶端）和顶端供应含生长素供体块的去顶切段的生长。在有氧条件下，倒置抑制生长素的向基运输并促进其向顶运输，而在无氧条件下，它不影响生长素在任一方向的运输。倒置减缓玉米中生长素30分钟脉冲峰值的向基运输。重力对生长素的产生、吸收、破坏、从切段中输出、在组织中的滞留或纯粹的物理移动的影响并不能解释倒置诱导的向基生长素运输抑制现象。得出的结论是，倒置（a）抑制向基运输，即生长素运输中代谢依赖的部分，结果（b）抑制生长，（c）促进生长素的向顶运输。
