We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Basis of coffee seed sensitivity to liquid nitrogen exposure: oxidative stress or imbibitional damage?
- Authors
Dussert, Stéphane; Chabrillangea, Nathalie; Montillet, Jean-Luc; Agnel, Jean-Pierre; Engelmann, Florent; Noirot, Michel
- Abstract
Two hypotheses, namely the occurrence of post-thaw oxidative stress or imbibitional damage, were tested to explain the high sensitivity of coffee seeds to liquid nitrogen (LN) exposure. Oxidative stress was studied by measuring primary and secondary products of lipid peroxidation in seeds during the desiccation and rehydration periods. The 4-hydroxynonenal (4-HNE) content of seeds remained constant throughout the desiccation step. No significant difference was observed between desiccated seeds and seeds desiccated and exposed to LN for the evolution of their 4-HNE and hydroperoxide contents during rehydration. In both cases, an increase in 4-HNE and hydroperoxide contents of seeds was observed during the first hours of culture under germination conditions, followed by a progressive decrease down to values comparable to those observed in desiccated seeds. The hydroperoxide composition of frozen seeds was not significantly different from that of control seeds. The (S)/(R) enantiomeric ratios of 9- and 13-hydroxy-octadecadienoic acid extracted from rehydrating seeds were chiral, suggesting that they originated from lipoxygenase activity. These results suggest that the high sensitivity of coffee seeds to LN exposure is not directly associated with the occurrence of an oxidative stress during post-thaw rehydration. The effect on seed viability of different rehydration procedures previously identified to reduce membrane imbibitional injury was studied after desiccation and LN exposure. Desiccation tolerance increased with, by increasing order, seed osmoconditioning, pre-heating and pre-humidifying prior to their culture under germination conditions. Among the four combinations of pre-humidification durations (24 or 48 h) and temperatures (25 or 37°C) tested, pre-humidification for 24 h at 37°C gave the highest level of desiccation tolerance. This rehydration procedure also dramatically increased seed viability after LN exposure. Seed desiccation sensitivity modelling in combination with the calculation of the decrease in seed water activity during cooling facilitated the explanation of the beneficial effect of controlled rehydration after desiccation and LN exposure. These results support the hypothesis that imbibitional membrane damage is involved in the sensitivity of coffee seeds to LN exposure.
- Subjects
OXIDATIVE stress; COFFEE; NITROGEN; LIPID metabolism
- Publication
Physiologia Plantarum, 2003, Vol 119, Issue 4, p534
- ISSN
0031-9317
- Publication type
Article
- DOI
10.1046/j.1399-3054.2003.00197.x