title: Regulation of programmed cell death by phytoglobins.
abstract: Programmed cell death (PCD) is a fundamental plant process in growth and development and in response to both biotic and abiotic stresses. Nitric oxide (NO) is a central component in determining whether a cell undergoes PCD, either as a direct elicitor of the response or as a factor in signal transduction from various hormones. Both NO and hormones that use NO as a signal transducer are mobile in the plant. Why do one set of cells die while adjacent cells remain alive, if this is the case? There is evidence to suggest that phytoglobins (Pgbs; previously termed non-symbiotic hemoglobins) may act as binary switches to determine plant cellular responses to perturbations. There are anywhere from one to five Pgb genes in plants that are expressed in response to growth and development and to stress. One of their main functions is to scavenge NO. This review will discuss how Pgb modulates cellular responses to auxin, cytokinin, and jasmonic acid during growth and development and in response to stress. The moderation in the production of reactive oxygen species (ROS) by Pgbs and the effects on PCD will also be discussed. An overall mechanism for Pgb involvement will be presented.
authors.affiliation: Department of Plant Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.|Department of Botany, Faculty of Science, Tanta University, Tanta 31527, Egypt.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Mira
authors.affiliation: Department of Plant Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada Rob_Hill@umanitoba.ca.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Hill
authors.affiliation: Department of Plant Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: Claudio
authors.initials: C
authors.lastname: Stasolla
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D018521:Plant Physiological Phenomena; D010940:Plant Proteins / Q000502:physiology*; D018517:Plant Roots / Q000254:growth & development; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000254:growth & development
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species
keywords: Auxin; ethylene; nitric oxide; phytoglobin; programmed cell death; reactive oxygen species.