Appearance of new transport capacity in wounded plants

Gersani, M. 1985. Appearance of new transport capacity in wounded plants.—J. exp. Bot. 36: 1809–1816. Bean hypocotyls were cut so that only a narrow transverse bridge connected the shoot and the root. The purpose of the work was to follow the processes of new, regenerative, vascular differentiation as expressed by the transport capacity of the wounded regions. Rapid transport of sucrose, auxin and gibberellin appeared as an exponential function of time. This transport probably expresses the functioning of newly differentiated sieve tubes and it comes close to the level of intact plants about 3 d after the plants are wounded. There was also a less rapid transport that appeared earlier, within 1 d of wounding, that was specific to auxin. The results supply critical parameters concerning new vascular differentiation and support the hypothesis that it is induced and oriented by the flow of auxin.