THE REGULATION AND FUNCTION OF TOBACCO SUPEROXIDE DISMUTASES

Our knowledge of superoxide dismutase (SODs)! in tobacco has increased greatly during the past few years. Genes encoding the four identified SOD isoforms of tobacco have been isolated and characterized. Analysi s of promoter-P-glucuronidase fusions has provided information on the cellular expression of SODs in tobacco and has constituted the basis f or studying SOD regulation Constitutive overproduction of SOD has been shown to confer increased tolerance to stress and has started to reve al subtle biochemical differences between SOD isoforms. Thus, thanks t o its convenience for molecular and physiological studies, tobacco has come forth in recent years as an excellent model system for studying the regulation and function of SOD in dicotyledonous plants. (C) 1997 Elsevier Science Inc.