Ethylene Signal Transduction Pathway in Cell Death During Aerenchyma Formation in Maize Root Cells: Role of Phospholipases

Ethylene biosynthesis is accelerated in roots of maize when they become hypoxic (partially O2 deficient) following soil flooding. The increased concentration of ethylene to which cells close to the root tip are exposed subsequently induces premature death and degeneration of cells in the root cortex, leaving air-filled cavities (aerenchyma). The interconnected cavities improve oxygenation of the root cells, and contribute to plant tolerance of flooding.