Functional electron microscopy of mitochondria is used by Vartapetian et al. (pp. 155-172) to consolidate the concept of two principal strategies of plant adaptation (�true� and �apparent�) and to demonstrate a key role for energy metabolism in determining the extent of anoxia tolerance. Studies of physiological roles for anaerobic synthesis of lipids, for nitrate as a possible terminal electron acceptor under anoxia, and in vitro selection of tolerant cell lines and regenerated plants are also described. The possibility that these anaerobic responses support the notion of a general adaptation syndrome in plants is discussed.