ISHS Acta Horticulturae 768: XXVII International Horticultural Congress - IHC2006: International Symposium on The Role of Postharvest Technology in the Globalisation of Horticulture
HYPOXIA-INDUCED BIOLOGICAL CHANGES INDICATE THE PRESENCE OF AN OXYGEN SENSOR IN FRUITS AND CUT CARNATIONS |
| Authors: | M. Asif, P. Trivedi, T. Solomos |
| Keywords: | 1-MCP, ethylene, CA storage, ACS1, apples, cellulase, ADH, polygalacturonase (PG) |
| Abstract:
The aspect of hypoxia that is most important for prolonging the storage life of climacteric-type detached plant tissues is its ability to retard the C2H4 climacteric onset. In the present report we offer data concerning the temporal relationships in apple fruits and carnation petals between O2 concentration and (a) C2H4 evolution, and (b) induction of ACC-synthase and alcohol dehydrogenase (ADH). The data show that in apples retardation of the C2H4 climacteric onset is saturable with respect to O2 and occurs when the O2 concentration drops below 6%. Furthermore, in apples and carnation petals the increase in the expression of ACC-synthase is also saturable with respect to O2 level. Hypoxia enhances the gene expression of ADH in both apples and carnations. In the latter this enhancement, too, is saturable with respect to O2. The data thus indicate that plant tissues contain a sensor that perceives O2 and when its concentration drops below a certain level, on the one hand it suppresses the develop¬mentally regulated processes that lead to the C2H4 climacteric onset, hence senescence, and on the other it enhances accumulation of ADH, an anoxic protein. Preliminary data indicate that the sensor contains Fe2+, and that in sweet potatoes hypoxia induces a metabolic depression. | |
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