MEMBRANE LIPIDS PEROXIDATION DURING THE SENESCENCE OF CUT CARNATION (DIANTHUS CARYOPHYLLUS L.)

A. Paulin, M.J. Droillard
Five morphological stages of Dianthus caryophyllus L. cv. Ember were distinguished: pre-opening, opening, beginning of withering, total withering. The analysis concerned only petals.

The start of ion leakage (resulting from the loss of membrane integrity) and of changes in fatty acids of polar lipids were observed between the opening and the beginning of withering.

The lipids peroxidation was evaluated by the analysis of malondialdehyde (MDA), peroxide levels, production of free radicals and ionic O2, and the lipoxygenase activity. The defense reactions were evaluated by measurement of superoxide dismutase and catalase activities. The fatty acids of polar lipids decreased sharply between the opening and the beginning of withering while the level of MDA increased clearly at the withering stage.

There was a sudden increase in free radical levels measured from the electron spin resonance (ESR) between the end of blooming and the onset of withering. There was also an increase in microsomal generation of superoxide radicals (measured from the ESR-Tiron Signal).

The lipoxygenase activity increased between pre-opening and withering. The catalase activity increased regularly from the initial stage until the withering stage, but the total superoxide dismutase activity strongly decreased during ageing.

The data collectively showed that the withering of cut carnation petals is linked to high peroxidation activity of membrane lipids.

Paulin, A. and Droillard, M.J. (1989). MEMBRANE LIPIDS PEROXIDATION DURING THE SENESCENCE OF CUT CARNATION (DIANTHUS CARYOPHYLLUS L.). Acta Hortic. 261, 51-58
DOI: 10.17660/ActaHortic.1989.261.5
https://doi.org/10.17660/ActaHortic.1989.261.5

Acta Horticulturae