The acropetal effects of indole-3-acetic acid in isolated shoot segments of Acer pseudoplatanus L. I. Growth responses of buds

Jacek A. Adamczyk


The subject of this investigation were growth reactions of two opposite lateral buds of Acer pseudoplatanus L. stem sections in response to application of indole-3-acetic acid (IAA) and other synthetic growth regulators below the buds. No effect of IAA upon the initiation of bud growth was noted, however, elongation of new shoots was inhibited. This acropetal effect of auxin was enhanced by simultaneous treatment with triiodobenzoic acid (TIBA) or benzyladenine (BA). TIBA alone caused even stronger retardation of shoot growth. Exactly the opposite effect was produced by gibberellic acid (GA3) applied even 30 cm below the buds. In this case TIBA could reverse the effect of GA3 treatment. The results concerning acropetal effects of auxin suggest that some type of signalling system functions independently of the direct action of the exogenous IAA.


bud growth; IAA; acropetal inhibition; correlative growth; Acer pseudoplatanus L.

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