Oxygen deficiency in corn seedling roots

​Excessive rain soon after corn seed germination, especially in low areas of fields with heavy soils, is frequently associated with stunted plants. Much of that is caused by lack of oxygen to the roots. Oxygen is needed to maintain metabolism in root cells not only for production of new root tissue but also of other functions including defending against potential pathogens.
 
A comparison of corn seedling root structures growing in aerated and non-aerated conditions showed that the cells between the outer epidermis layer and the inner vascular tissue tended to collapse in the seminal roots lacking oxygen. These cells tended to be empty of cytoplasm but instead became empty spaces separated by the cell walls.  Lack of cytoplasm was apparently the cause of reduced active uptake of potassium and assumedly other minerals by the seminal roots.
 
This study (Plant Physiol. (1980) 65, 506-511)showed that corn seedlings in oxygen deficient media tended to develop nodal roots sooner than those with adequate root oxygen as an apparent reaction to stress of the seminal roots. Prolonged oxygen stress ultimately resulted in less total root volume.  
 
Symptoms of mineral deficiency in young corn plants in excessive, prolonged water areas of fields is associated with oxygen deficiency in corn roots.  This results in less mineral uptake into roots and transfer of the minerals through the vascular system to the shoots.  Prolonged oxygen deficiency results in reduced total root volume, less minerals available for shoot growth and potentially less water uptake in late season dry environment.