Influence of farnesol on the morphogenesis of Aspergillus niger

Abstract

Farnesol was the first quorum-sensing regulator to be found in eukaryotic cells. In Candida albicans, a dimorphic fungal human pathogen, farnesol blocks the yeast-to-filamentous growth transition. Here we show that in Aspergillus niger farnesol acts as an inhibitor of conidiation: Colonies grown on media containing farnesol were unable to develop conidia. Although farnesol treated A. niger cultures exhibited a colony morphology resembling the "fluffy" phenotype of A. nidulans, which is caused by a hyperactive G-protein/cAMP pathway, the intracellular level of cAMP in A. niger mycelia grown in presence of farnesol is greatly diminished. Furthermore, whereas inhibiting adenylyl cyclase led to a farnesol-like effect, the addition of external cAMP inhibited conidiation without causing a "fluffy" phenotype. This suggests that the mechanisms regulating conidiation in A. niger and A. nidulans are different.

Volatile sesquiterpenes from fungi: what are they good for?

“…Additionally, C. effect was shown to be also due to volatile transmission of the sesquiterpene alcohol (Semighini et al 2006). Similar alterations by farnesol in growth and morphology are described in the Ascomycota species Fusarium graminearum, Aspergillus niger and Aspergillus fumigatus (Lorek et al 2008;Semighini et al 2008;Dichtl et al 2010). Dichtl et al further suggest that farnesol is interfering in the CWI pathway (cell wall integrity) of which many components are conserved within the kingdom fungi and therefore display an advantage in competition for farnesol-producing fungal species.…”

Effect of farnesol on morphogenesis in the fungal pathogenPenicillium expansum

“…6 -The genome DNA (each 10 μl) agarose identification. The germ tube was treated with 25-400 μM farnesol or not for 2 h. The genome DNA was extracted by CTAB and identified in 2% agarose 120 mV for 2 h. and addition of cAMP can moderate intracellular amounts of cAMP which dramatically decreased by farnesol, whereas conidia formation is again blocked by adding higher cAMP concentration (Lorek et al, 2008). The result showed that cAMP plays a crucial role in spore formation and colony morphogenesis.…”

“…Recently it has been reported that external farnesol induced apoptosis-like phenotype in a number of filamentous fungus, e.g., Aspergillus nidulans, Fusarium graminearum and Candida dubliniensis (Henriques et al, 2007;Lorek et al, 2008;Semighini et al, 2006Semighini et al, , 2008.…”

Proteome analysis of the farnesol-induced stress response in Aspergillus nidulans—The role of a putative dehydrin

“…Moreover, the same authors provided evidence for the mediation of farnesol-induced apoptosis by the FadA heterotrimeric G protein, since the deletion of the negatively acting G-protein regulator FlbA resulted in the hyperactivation of the Gα protein FadA and consequently led to increased sensitivity against farnesol [14]. Also an altered cAMP level has been suggested to be involved in the G protein-dependent signalling of farnesol in both A. nidulans and A. niger [10,18]. Recent studies uncovered further molecular targets and signalling pathways responsible for farnesol susceptibility.…”

“…It is produced by the human pathogenic fungus Candida albicans and inhibits the yeast-to-hyphae transition and the formation of biofilms [3,4]. Furthermore, farnesol exhibits numerous effects on several microorganisms, mammalian cells and plants [5][6][7][8][9][10][11]. Its bacteriostatic and fungistatic effects make it also an interesting compound for hygienic applications.…”