Calcium-mediated responses of maize to oxygen deprivation

Oxygen limitation dramatically alters the patterns of gene expression as well as development of plants. Complete removal of O₂ leads to an immediate cessation of protein synthesis followed by a selective synthesis of about twenty anaerobic proteins in maize (Zea mays L.) seedlings. Among these are enzymes involved in glycolysis and related processes. However, inducible genes that have different functions were also found; they may function in other, perhaps more long-term, processes of adaptations to flooding, such as aerenchyma formation and root-tip death. Our recent research has addressed two questions: how these gene expression changes are initiated and how do these responses culminate in the overall adaptation of plants to flooding-stress. The results obtained indicate that an early rise in cytosolic Ca²⁺ as well as a quick establishment of ionic homeostasis may be essential for the induction of adaptive changes at the cellular as well as organismal level.