Abstract
Two spatially localized phases of glycogen accumulation were detected by electron microscopy after cytological staining of thin sections of Streptomyces coelicolor A3 (2) colonies. In phase I, glycogen granules were present in hyphae in the air—agar interface region of colonies that were undergoing aerial mycelium formation, though absent from aerial hyphae themselves. With one exception (a bldF mutant, which contained abundant glycogen), the absence of aerial mycelium caused by various developmental mutations (
bldA, bldB, bldC, bldD, bldG
and
bldH
mutations) was associated with a virtual absence of detectable glycogen. Mutations that allow aerial hyphae to form but prevent or interfere with the septation needed for spore formation (
whiA,whiB, whiG, whiH
and
whil
mutations) did not impair phase I deposition. In phase II, abundant glycogen granules were present in aerial hyphal tips during intermediate stages of sporulation, but disappeared as spores matured. Phase II glycogen accumulation was observed with
bldA, bldC, bldD
and
bldG
mutants grown with mannitol as carbon source — conditions that allowed normal aerial mycelium development and sporulation; but phase I deposition was still at a very low level in these colonies. Glycogen was also deposited in the coiling tips of aerial hyphae of
whiA
, whiB, whiH and whil mutants, and sporadic clusters of granules were present throughout
whiG
colonies. Significantly, glycogen was deposited in spore chains that developed ectopically in the normally sporeand glycogen-free substrate mycelium when multiple copies of
whiG
were present. Overall, the two phases of glycogen synthesis (and degradation) appear to be under separate developmental control rather than being mainly responsive to external growth conditions. Phase II glycogen levels were particularly high in a
whiE
mutant defective in spore pigment biosynthesis, and particularly low when hyper-pigmentation was induced by additional copies of the
whiE
genes. Spore pigment may therefore be a major sink for carbon stored as glycogen during sporulation. The possibility is discussed that, in addition to supplying carbon and energy at particular locations, glycogen synthesis and degradation may also play a part in morphogenesis by influencing turgor pressure.
Subject
General Agricultural and Biological Sciences,General Biochemistry, Genetics and Molecular Biology
Reference72 articles.
1. The wrinkled-seed character of pea described by Mendel is caused by a transposon-like insertion in a gene encoding starch-branching enzyme
2. Polyoside intracellulaire implique dans la sporulation de Clostridium butyricum;Bergere J.L.;Ann. Microbiol.,1975
3. Occurrence of polysaccharide granules in sporulating hyphae of Streptomyces viridochromogenes;Brana A.F.;J. Bad.,1980
4. Characterization of intracellular polysaccharides of Streptomyces
5. Glycogen and trehalose accumulation during colony development in Streptomyces antibioticus;Brana A.F.;J. Gen. Microbiol.,1986
Cited by
36 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献