ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Requirement of spermidine for developmental transitions in Aspergillus nidulans (2002)

Jin, Yuan ; Bok, Jin Woo ; Guzman-de-Peña, Doralinda ; [et al.]

Oxford, UK : Blackwell Science Ltd

Molecular microbiology 46 (2002), S. 0

add to mindlist on the mindlist

Details

ISSN: 1365-2958

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Biology , Medicine

Notes: Deletion of the spermidine synthase gene in the fungus Aspergillus nidulans results in a strain, ΔspdA, which requires spermidine for growth and accumulates putrescine as the sole polyamine. Vegetative growth but not sporulation or sterigmatocystin production is observed when ΔspdA is grown on media supplemented with 0.05–0.10 mM exogenous spermidine. Supplementation of ΔspdA with ≥ 0.10 mM spermidine restores sterigmatocystin production and ≥ 0.50 mM spermidine produces a phenotype with denser asexual spore production and decreased radial hyphal growth compared with the wild type. ΔspdA spores germinate in unsupplemented media but germ tube growth ceases after 8 h upon which time the spores swell to approximately three times their normal diameter. Hyphal growth is resumed upon addition of 1.0 mM spermidine. Suppression of a G protein signalling pathway could not force asexual sporulation and sterigmatocystin production in ΔspdA strains grown in media lacking spermidine but could force both processes in ΔspdA strains supplemented with 0.05 mM spermidine. These results show that increasing levels of spermidine are required for the transitions from (i) germ tube to hyphal growth and (ii) hyphal growth to tissue differentiation and secondary metabolism. Suppression of G protein signalling can over-ride the spermidine requirement for the latter but not the former transition.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1046/j.1365-2958.2002.03201.x

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Correlation between the regulation of sterigmatocystin biosynthesis and asexual and sexual sporulation in Emericella nidulans (1998)

Guzmán-de-Peña, Doralinda ; Aguirre, Jesús ; Ruiz-Herrera, José

Springer

Antonie van Leeuwenhoek 73 (1998), S. 199-205

add to mindlist on the mindlist

Details

ISSN: 1572-9699

Keywords: Emericella nidulans ; Aspergillus nidulans ; sterigmatocystin ; mycotoxins ; sporulation ; polyamines ; diaminobutanone ; brlA

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract We analyzed the regulation of sterigmatocystin biosynthesis in wild type and mutant strains of Emericella nidulans (= Aspergillus nidulans). A positive correlation between both asexual and sexual sporulation and synthesis of the mycotoxin was observed. Those conditions which favored sporulation stimulated sterigmatocystin formation, and vice versa. Both processes were stimulated by light in a + genetic background. In contrast, they were inhibited by diaminobutanone, an inhibitor of ornithine decarboxylase. The effect of this inhibitor was partially reverted by putrescine addition. Partial supplementation of specific requirements to auxotrophic mutants allowed normal vegetative growth, but interfered with asexual sporulation and sterigmatocystin biosynthesis. Synthesis of the mycotoxin was neither affected in a brlA mutant or in developmental mutants blocked at later steps in sporulation. As in wild type strain, diaminobutanone inhibited sterigmatocystin biosynthesis and cleisthotecia formation in the brlA mutant, and its effect was reverted by addition of putrescine. The inhibitor also affected the transcription of brlA. Our results indicate that sporulation and the synthesis of sterigmatocystin are co-regulated at a step previous to the brlA execution point.