Anaerobic Metabolism and the Production of Organic Acids

This chapter discusses the biochemical adaptations to anoxia. The ability of plants to survive anaerobic conditions depends on morphological and anatomical features. It also depends on physiological and biochemical factors. Leaves seldom experience anaerobic conditions; however, flooding frequently produces anaerobic conditions for roots. Thus, structural features such as aerenchyma may provide the roots with a limited supply of oxygen from the aerial parts of the plant. At the biochemical level, a pronounced Pasteur Effect may ensure an adequate supply of ATP during short periods of anaerobiosis. However, in the longer term, the accumulation of the products of glycolysis may injure the plant. To survive long periods of anaerobiosis, plants may have evolved at least three biochemical strategies. Plants have developed mechanisms to maintain a high energy charge and allow limited growth. This mechanism appears to be found in few cases such as rice. Plants maintain the glucose supply and the adjustment of the carbon metabolism to avoid the accumulation of toxic products.