|Authors: ||M. Bajji, F. Gastiny, P. du Jardin|
|Keywords: ||Solanum tuberosum L., thiourea, hydrogen peroxide, dormancy breakage, suberization, post-harvest|
Tuber sprouting and wound-healing are two major aspects of the potato (Solanum tuberosum L.) management.
Elucidation of the underlying mechanisms is of a great economic importance since tubers are still suffering from a poor sprouting quality and are prone to damage during and after harvest.
In the present study, we investigated the effect of a catalase inhibitor (thiourea) on the development of sprouting and wound-healing of potato harvested tubers.
In the case of sprouting, tubers (cv. ‘Désirée’) treated with 250 mM thiourea for 2 hours were characterized by a rapid and high sprouting percentage as well as by a high percentage of sprouted eyes in comparison with those treated with water.
Regarding wound-healing, tubers (cv. ‘Mérit’) were cut (i.e. wounded) longitudinally and immediately treated either with water or with 100 mM thiourea for 2 hours and allowed to wound-heal for 2 weeks.
Tuber-halves previously treated with thiourea showed a significant loss of their fresh weight and were susceptible to pathogen attack when compared to those treated with water, indicating that the wound-healing process would be impaired in the former as opposed to the latter.
In order to see whether thiourea acts via catalase inhibition and consequently via (the expected) endogenous hydrogen peroxide accumulation, tubers were treated with exogenous hydrogen peroxide (20-25 mM) for 2 hours as with thiourea.
In general, the observed effects were similar to those induced by thiourea for both tuber sprouting and wound-healing processes, suggesting that hydrogen peroxide metabolism, especially its scavenging by catalase activity, may play a primordial role in the control of these two important aspects of the potato tuber post-harvest management.
Download Adobe Acrobat Reader (free software to read PDF files)
URL www.actahort.org Hosted by KU Leuven