Studies on plant hormones and the relation with onion and potato dormancy and sprout growth

Ethylene is known to have profound effects on the postharvest quality of climacteric fresh produce. Understandably, far less emphasis has been given to understanding the role that ethylene might have in the regulation of dormancy or senescence in non - climacteric systems. It is now well established that continuous ethylene supplementation can extend the storage life of onions and potatoes even though these organs are low ethylene producers. In potato ethylene triggers dormancy break, but also inhibits sprout growth. In onion, both ethylene and the ethylene antagonist 1 - methylcyclopropene (MCP) inhibit sprouting, suggesting a surprisingly similar pattern of control. Indeed, 1-MCP may act synergistically when combined ethylene. Given this apparent dichotomy, the underlying mechanisms of several hormones in regulating entry into dormancy, dormancy release and rate of post ? dormant sprout growth will be discussed since new evidence suggests that abscisic acid has a role in establishing dormancy; that cytokinins are required for endo - dormancy break, and that gibberellins and ethylene have opposing roles in sprout extension. ? ? Sources:UNDERSTANDING THE UNDERLYING MECHANISMS BY WHICH ETHYLENE SUPPLEMENTATION EXTENDS STORAGE LIFE OF ONIONS AND POTATOESTerry, L.A.(*), Cools, K. and Foukaraki, S.l.a.terry@cranfield.ac.ukCranfield University, UK CA MA 2013, XI International Controlled & Modified Atmosphere Research Conference, Trani (Italy), 3-7 June 2013 The picture is by, Onions and Potatoes, a web site specialized in both products.