ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Abstract Glyphosate was considerably more growth inhibitory to N2-assimilating than to ammonium-assimilating cultures of N. muscorum. The herbicide, while inhibiting nitrogenase activity and ammonium [14C]-methylammonium) uptake activity caused significant increase in the biosynthetic activity of in vivo glutamine synthetase (GS) in N2-assimilating or ammonium-assimilating cultures and nearly 50% derepression of heterocyst formation and nitrogenase activity in ammonium assimilating cultures. The differential toxicity of the herbicide to N2-fixing cultures led us to use this herbicide as selective agent to isolate a class of mutant clones on ammonium-supplemented medium which lacked heterocyst differentiation (Het−), nitrogenase activity (Nif−) and ammonium [14C]-methylammonium) uptake activity (Amt−). It is concluded that heterocyst differentiation, nitrogenase activity and ammonium uptake activity are all under the regulatory control of common genetic determinants in the cyanobacterium.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.1989.tb03443.x
