Abstract:After flooding of maize seedlings for fourteen days, their stomata were closed, and total nucleic acid was accumulated in subwater knots before adventitious roots appeared. Aerenchyma were developed and some physiological and morphological changes were induced in fourweek old Zea mays L. seedlings. It aeems possible that the maize seedlings had adapted to the flood circumstances by forming adventitious roots on submerged knots of the stems, which was not only thick and white but also with no root hairs and grew upwards.