21277986
not annotated - annotated - LINNAEUS only
The molecular and genetic basis of conidial pigmentation in Aspergillus niger.
A characteristic hallmark of Aspergillus niger is the formation of black conidiospores. We have identified four loci involved in spore pigmentation of A. niger by using a combined genomic and classical complementation approach. First, we characterized a newly isolated color mutant, colA, which lacked pigmentation resulting in white or colorless conidia. Pigmentation of the colA mutant was restored by a gene (An12g03950) which encodes a putative 4'phosphopantetheinyl transferase protein (PptA). 4'Phosphopantetheinyl transferase activity is required for the activation of Polyketide Synthases (PKSs) and/or Non-Ribosomal Peptide Synthases (NRPSs). The loci whose mutation resulted in fawn, olive, and brown color phenotypes were identified by complementation. The fawn phenotype was complemented by a PKS protein (FwnA, An09g05730), the ovlA mutant by An14g05350 (OlvA) and the brnA mutant by An14g05370 (BrnA), the respective homologs of alb1/pksP, ayg1 and abr1 in A. fumigatus. Targeted disruption of the pptA, fwnA, olvA and brnA genes confirmed the complementation results. Disruption of the pptA gene abolished synthesis of all polyketides and non-ribosomal peptides, while the naphtho-gamma-pyrone subclass of polyketides were specifically dependent on fwnA, and funalenone on fwnA, olvA and brnA. Thus, secondary metabolite profiling of the color mutants revealed a close relationship between polyketide synthesis and conidial pigmentation in A. niger.
Ann file
T1 Species 60 77 Aspergillus niger
N1 Reference T1 Taxonomy:5061
T2 Species 109 126 Aspergillus niger
N2 Reference T2 Taxonomy:5061
T3 Species 231 239 A. niger
N3 Reference T3 Taxonomy:5061
T4 Species 1051 1063 A. fumigatus
N4 Reference T4 Taxonomy:746128
T5 Species 1535 1543 A. niger
N5 Reference T5 Taxonomy:5061