The effects of ethylene, methyljasmonate and 1-MCP on abscission of cherry tomatoes from the bunch and expression of endo-1,4-β-glucanases

Cherry tomatoes harvested as bunches are sensitive to abscission during storage and this is a significant commercial problem for this produce. We examined effect of methyl jasmonate (MJ), ethylene and the inhibitor of its action, 1-methlcyclopropane (1-MCP) on abscission during storage and on the expression of six tomato endo-1,4-beta-glucanases (EGase). It is reported that exogenous methyl jasmonate, (1 mM) enhanced abscission during storage. as did ethylene (50 muL L-1). Application of 100 nL L-1 of 1-MCP for 24 h inhibited fruit abscission but only partial effect was obtained when it was applied 3 h after supplying methyl jasmonate or ethylene. The effects 1-MCP, methyl jasmonate and ethylene on expression of tomato endo-1,4-beta-alucanases, Cel1, Cel2, Cel3, Cel 5, Cel7 and Cel8 were examined in abscission zone tissue at five time points during storage. The expression of Cell and Cel5 increased during storage, further establishing their role in abscission. Both ethylene and methyl jasmonate enhanced the expression of tomato endo-1,4-beta-glucanases whereas, 1-MCP blocked the expression of the genes. These results demonstrate the benefit of 1-MCP in preventing fruit abscission and provide a wide view on the role of endo-1,4-beta-glucanases in abscission of cherry tomatoes during storage. (C) 2004 Elsevier Ireland Ltd. All rights reserved.