ISHS Acta Horticulturae 329: VII International Symposium on Plant Growth Regulators in Fruit Production
TRANSPORT AND METABOLISM OF INDOLE-3-BUTYRIC ACID IN EASY- AND DIFFICULT-TO-ROOT CUTTINGS OF SWEET CHERRY (PRUNUS AVIUM L.) |
| Authors: | E. Epstein, S. Zilkah, G. Faingersh, A. Rotebaum |
| Keywords: | Tissue culture, rooting, IBA glucose |
| Abstract:
The transport and metabolism of IBA were studied in easy-to-root (ER) and difficult-to-root (DR) cultivars of sweet cherry (Prunus avium L.) in an aseptic system. Plantlets of both cultivars were grown on rooting agar medium supplemented with [3H]-indole-3-butyric acid (IBA). Most of the radioactivity (80%) was found in the bases of shoots of both cultivars and very little was transported to the shoots and leaves. ER plantlets absorbed more IBA for a longer period than DR plantlets. Both cultivars metabolized IBA rapidly to an ester, probably with glucose. After one day, no free IBA could be detected by autofluorography in the extracts of the DR cultivar. The ER cultivar, on the other hand, metabolized the conjugate slower, and after one day an intense spot of IBA was still visible on the autofluorogram. Free IBA disappeared after the second day, but re-appeared after 4 days and disappeared again after 7 days. We postulate that the easy-to-root cultivar, as opposed to the difficult-to-root cultivar, has the ability to hydrolyze the ester conjugate at the appropriate time to release free IBA which may promote root initiation. Conjugation was inhibited by 1,6-dihydroxyacetophenone (DHAP) (a known inhibitor of conjugation) only in the DR cuttings. Treatment of DR cv cuttings of olive increased significantly the percent of rooting. | |
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