Some Criticisms of the Use of Nojirimycin as a Specific Inhibitor of Auxin-induced Growth

Abstract

Summary Nojirimycin will inhibit auxin-induced growth in Helianthus hypocotyls if the tissue has been pre-treated with the inhibitor. This agrees with data previously published for Avena and Pisum ( Nevins , 1975 a, b). Geotropic curvature is also inhibited in nojirimycin pretreated Helianthus hypocotyls. Nojirimycin has no effect on acid-induced growth in either short or long-term experiments. If nojirimycin and auxin are added simultaneously to Helianthus segments inhibition of auxin-induced growth does not occur for 3 hour, wheareas it can be shown that nojirimycin can inhibit the activity of the enzyme β-glucosidase in the segment within 10–15 min in both peeled and unpeeled segments. It is argued that this discrepancy between the rate of penetration of nojirimycin and the kinetics of the inhibition of auxin-induced growth shows that nojirimycin is not inhibiting auxin-induced growth in a specific manner.