Implication of Free Radicle in Deterioration of Recalcitrant Propagules During Wet Storage
The studies on both maize (Leprince et al., 1990) and Q. robur (Hendry et al.,1992 Finch-Savage et al., 1993) have been carried out on desiccation-sensitive material that has been dehydrated.
These provide convincing evidence that free radical mechanisms are involved in dehydration-related viability loss.
It has been argued above that vacuolation during germinative development in wet-stored recalcitrant propagules imposes a desiccation stress in a different way, by the withholding of required water rather than the removal
of existing water.
Under these circumstances, it can be argued that resultant out-of-phase metabolism could result in similar free radical generation and "escape," with parallel consequences.
Also, because of the deranged metabolic situation, free radical inactivation (by scavengers or enzymatically) would be suboptimal, or even inoperative, and organized repair mechanisms can similarly be argued to be ineffective.
In the normal situation where water is readily available from external sources during germination, uncontrolled free
radical generation should be minimal, antioxidant mechanisms would operate optimally, and normal turnover and repair mechanisms would be fully functional.