ISHS Acta Horticulturae 682: V International Postharvest Symposium
IMPORTANCE OF HORMONAL PROFILE ON THE ONSET OF RIPENING IN GRAPE BERRIES OF VITIS VINIFERA L. |
| Authors: | L. Gény, C. Deytieux, B. Donèche |
| Keywords: | abscisic acid, berries, change of colour, chlorophyll, indole acetic acid, ripening process |
| Abstract:
Grape berry is classified as a non climacteric fruit which accumulates abscisic acid (ABA) at the beginning of ripening. It seems that this phytohormone is an activating signal of ripening and we intend to investigate this in depth. As a part of this investigation, we have performed treatments at the beginning of ripening process (1% of berries changed their colour). We have treated grape berries with ABA and the fungal toxin fusicoccin, with is known to have an antagonistic effect towards ABA in plant tissue. Both treatments delay the increase of berry weight. The exogenous application of ABA results in an advancement of the change of colour, by faster decreasing chlorophyll levels. The hormonal profile is modified during colour change period: ABA levels are enhanced and indole acetic acid (IAA) levels are decreased in the berry. This treatment seems to advance the ripening process. Application of fusicoccin to berries delays the chlorophyll degradation. This is accompanied by a decrease of ABA levels compared to the control. These results show that exogenous treatments with ABA modify the hormonal profile and the ripening process. The roles of ABA and IAA are discussed in relation to expression of some genes involved in the ripening process. | |
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