1. After cutting, IAA content in the 0-5mm region below the cut surface of etiolated
Stizolobium epicotyl increased considerably and IAA destructive activity in the cut region (0-2mm) was markedly induced under the dark conditions. Thus, the changes in the IAA level in the cut region of
Stizolobium epicotyl could not be explained with those in the level of IAA destroying activity.
2. In
Vicia epicotyl, IAA content of the region (0-3mm) increased markedly in a day after cutting, but declined sharply thereafter. In IAA treated epicotyl, a remarkably high IAA level in the region, caused by IAA application, dropped rapidly in three days after IAA treatment. However, the IAA level was maintained at rather a high level thereafter, as compared with that in the non-treated epicotyl. IAA destructive activity was induced in the cut region (0-2mm) after cutting and much increased afterwards. IAA treatment seemed to retard the induction of the activity. High IAA level in the cut region appeared to be, at least partly, attributed to the low rate of IAA destruction.
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