Madi, L., Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Wang, X., Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Kobiler, I., Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Lichter, A., Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Prusky, D., Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
 

The expression of the avocado homologue avfad9 encoding Δ 9-stearoyl-ACP desaturase was enhanced by multiple stimuli: inoculation with Colletotrichum gloeosporioides, exposure to ethylene or CO 2, low temperature (4°C) and fruit wounding. This enhanced expression was correlated with an increase in the preformed antifungal (Z, Z)-1-acetoxy-2-hydroxy-4-oxo-heneicosa-12, 15-diene. Treatments of fruits with ethylene that enhanced the up-regulation of avfad9 also increased the concentration of 18:2 fatty acid and the incorporation of 14C-linoleate into the antifungal diene. Fruits with enhanced Δ9stearoyl-ACP desaturase expression were more resistant to C. gloeosporioides. It is suggested that the enhanced Δ 9stearoyl-ACP desaturase expression is involved in elevation of unsaturated 18:2. It is also concluded that similar treatments enhance the incorporation of labeled 18:2 into the antifungal diene and elicit the concurrent enhanced resistance to fungal attack. © 2003 Elsevier Ltd. All rights reserved.