Detached leaves were used to study the effect of hydration on some physiological aspects in shade (Syngonium podophyllum) as well as light grown (Lycopersicon esculentum Mill) plant species. In addition, these two plants were used to investigate the role of light to accelerate the effect of dehydration on peroxidase activity and chlorophyll degradation. Relative water content of both tomato and S. podophyllum (nephtytis) decreased drastically in three days under dehydration condition. Tomato leaves are thicker and fleshier than those of nephtytis; it may explain why the reduction in relative water content of tomato was higher than that of nephtytis, especially under dark condition. In three days, the reduction in total pigments of nephtytis was higher than those of tomato, especially under light condition. Both plant species showed reduction in total carbohydrate and protein contents resulted from the reduction of insoluble fractions. Under dehydration condition, both plant species showed disappearance (high in nephtytis) or appearance (high in tomato) of some polypeptides. In both plant species, increase of the soluble carbohydrate and protein fractions, enhance the peroxidase activity and expression of new polypeptides were three mechanisms to avoid the negative effects of dehydration but they were not enough to regulate the oxidative risks exerted by three days dehydration.