Flood Tolerant and Flood Sensitive Plants Under Primary and Secondary Anoxia

Abstract

The elucidation of the mechanisms of plant adaptation to anaerobic environments and the causes of plant injury and death in oxygen-free conditions are two fundamental problems which have been studied extensively during the last 20 years. The high sensitivity of root cell ultrastructure to oxygen deficiency and facilitated oxygen transport from shoots to roots of flood-tolerant plants indicate that adaptation of plants to oxygen shortage in the rooting medium is achieved by the avoidance of anaerobiosis in root cells. The second main strategy is metabolic adaptation. This is realised at the molecular level in the total absence of oxygen. Both strategies are discussed using results obtained mostly from experiments with rice. In addition, the responses of flood-sensitive plants such as wheat, pea and maize under primary and secondary anoxia are considered.