Submitted to: Russian Journal of Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2003
Publication Date: 12/15/2003
Citation: Subbaiah, C.C., Sachs, M.M. 2003. Calcium-mediated responses of maize to oxygen deprivation. Russian Journal of Plant Physiology. 50:752-761. Interpretive Summary: 1) Rationale: Oxygen availability is the primary limiting factor for plant growth in flooded soils. The sudden excess of water due to flooding can threaten the food supply of human populations. The goal of this study was to characterize molecular events induced during low oxygen conditions in maize during flooding. 2) Accomplishments: The results indicate that flooding causes a release of calcium ions and this signals genes that induce structural and cellular changes in maize plants. The process appears to be involved in the mechanism of how a seedling responds during flooding stress. 3) Significance: The understanding of this mechanism in a plant's response to low oxygen-stress conditions will allow for a greater understanding of how plants attempt to cope with this stress and may allow for effective methods to produce crop plants that are tolerant to flooding.
Technical Abstract: 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; which 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. Our results 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.