?Why does the ethylene delays sprouting in potato?

Ethylene is used as a commercial potato sprout suppressant, yet the role of ethylene in potato dormancy is unclear and contradictory. In three consecutive seasons, potato was treated with continuous air, continuous ethylene (10 ?l l-1), transferred from air to ethylene or vice versa at first indication of sprouting (10% eye movement 'peeping' of the control tubers). The ethylene binding inhibitor, 1-methylcyclopropene, was applied (1 ?l l-1 for 24 h) either at harvest and/or at first indication of sprouting. Tubers were stored at 6?C for 30 weeks and assessed. A rise in ABA content was observed in response to ethylene application while 1-MCP blocked the ethylene induced rise in ABA caused by exogenous ethylene. The increase in ABA caused by ethylene may delay dormancy break yet 1-MCP blocked this rise in ABA with no apparent effect on sprout behaviour. Sucrose is a prerequisite signalling molecule for hormonal dormancy control. 1-MCP reduced the ethylene induced rise in sucrose content therefore although 1-MCP reduced ABA, the reduction in sucrose content may have still delayed sprout initiation. This said, the level of sucrose in the 1-MCP treated tubers did not decrease below that of the control. Taken together, ABA and sucrose may play a role in the sprout suppressing ability of exogenously applied ethylene yet it is clear that other factor(s) are involved.SourcesEffect of ethylene supplementation on abscisic acid metabolism of potato (Solanum tuberosum L.) tubers during storageM. del Carmen Alamar1, Sofia Foukaraki2, Katherine Cools3, Leon A. Terry41Cranfield University, Postharvest Bioscie., School of Energy, College Road, MK430AL Cranfield, Bedfordshire, United Kingdom2Cranfield University, Heraklion, Greece338 Rose Hill, Binfield, Binfield, United Kingdom4Cranfield University, Cranfield, United KingdomVIII International Postharvest Symposium, Cartagena, Spain