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 condit...

There have been several reports of light effe-cts on the movement of growth-regulating substances in plants. Shen-Miller and Gordon (6) found that phototropically active blue light decreased the basipetal movement of IAA in Zca coleoptile sections. Similarly, Thornton and Thimann (7) *observed that blue light induced a transient decrease in the basipetal movement of IAA in Avena coleoptile tiss...

Asyximmetry of ildoleacetic aci(l distribution has lbeen associated witlh the (levelollment of plant bioelectric l)otentials. In the absenlce of auxinl. no detectable l)otential (levelops, but wvhen atuxin is suppliedl auxin asymmlletries cause(l by(lifferelnces in translport give rise to bioelectric potelntials (4. 6). Recenltlv (2) it \-as demonistrate(d that uinder anoxia. vhere no potential...