School of Biological Sciences, University of East Anglia, Norwich, NOR. 77H, Great Britain.
Plant Physiol. 1967 Jun;42(6):831-9. doi: 10.1104/pp.42.6.831.
The movement of IAA-(14)C through coleoptile segments of Avena and Zea has been investigated under aerobic and anaerobic conditions. The results are as follows: Zea. Using a 5-mm segment and a 2-hour transport period anaerobic conditions reduced the total uptake of (14)C from an apical donor by 74% and the proportion of the total found in the receiving block by at least 45%. Anaerobic conditions reduced total uptake from a basal donor by 58% but no (14)C reached the apical receiving block in either air or N(2). Uptake from apical and basal donor blocks in N(2) is closely similar.The presence of (14)C in the basal receiving blocks, and its absence in the apical receiving blocks, in N(2) suggests that even in anaerobic conditions movement of IAA is polarized basipetally, although the movement occurs at only a fraction of the rate found in air.Anaerobic conditions induced a similar reduction in basipetal movement of IAA in upper and lower 5-mm segments taken from the apical 10 mm of a Zea coleoptile.Using 10-mm Zea segments no (14)C was recovered in the receiving blocks at the basal end of the segment after 2 and 4 hours in N(2) whereas large amounts were recovered in air.Avena: Using 5-mm segments and a 2-hour transport period the total uptake of (14)C from an apical donor is reduced by 83%. Movement of (14)C into the basal donor is totally inhibited in N(2). Total uptake of (14)C from a basal donor is reduced by 61% in nitrogen and no (14)C reached the apical receiving blocks regardless of the atmospheric conditions.A time course for the movement of (14)C into the basal and apical receiving blocks through 5-mm segments showed that in air the amount in the basal receivers increased for 4 hours and then remained approximately uniform. In N(2) no significant (14)C reached the receivers until 6 to 8 hours after the application of donors but even then the amounts were about 12 to 14% of that in aerobic receivers. Movement of (14)C into apical receivers was similar in air and in nitrogen and even after 6 to 8 hours the amount of radioactivity barely reached significant levels.
在有氧和无氧条件下，研究了 IAA-（14）C 通过玉米和燕麦胚芽鞘段的运动。结果如下：玉米。使用 5 毫米段和 2 小时的运输期，无氧条件使（14）C 从顶端供体的总摄取量减少了 74%，并且至少减少了 45%的总摄取量在接收块中。无氧条件使从基部供体的总摄取量减少了 58%，但在空气或 N（2）中都没有（14）C 到达顶端接收块。在 N（2）中，从顶端和基部供体块的摄取非常相似。在 N（2）中，基部接收块中存在（14）C，而顶端接收块中不存在（14）C，这表明即使在无氧条件下，IAA 的运动也是极性的，向基部，但运动速度仅为空气速度的一小部分。无氧条件诱导了从玉米胚芽鞘顶端 10 毫米处的上 5 毫米段和下 5 毫米段中 IAA 向基部的运动相似的减少。使用 10 毫米的玉米段，在 N（2）中 2 小时和 4 小时后，在段的基部末端没有回收（14）C 接收块，而在空气中则回收了大量（14）C。燕麦：使用 5 毫米段和 2 小时的运输期，从顶端供体中（14）C 的总摄取量减少了 83%。在 N（2）中，（14）C 向基部供体的运动完全被抑制。在氮气中，从基部供体中（14）C 的总摄取量减少了 61%，无论大气条件如何，（14）C 都没有到达顶端接收块。通过 5 毫米段进入基部和顶端接收块的（14）C 运动的时间过程表明，在空气中，基部接收器中的量在 4 小时内增加，然后保持大致均匀。在 N（2）中，直到供体施加后 6 到 8 小时，才没有显著的（14）C 到达接收器，但即使在那时，（14）C 的量也约为有氧接收器的 12%到 14%。（14）C 进入顶端接收器的运动在空气中和氮气中相似，即使在 6 到 8 小时后，放射性的量也几乎没有达到显著水平。
