The Polyketide Synthase Gene
<i>pks4</i>
of Trichoderma reesei Provides Pigmentation and Stress Resistance
Lea Atanasova, Benjamin P. Knox, Christian P. Kubicek, Irina S. Druzhinina, Scott E. Baker
Eukaryotic Cell·2013·82 citations
<jats:title>ABSTRACT</jats:title>
<jats:p>
Species of the fungal genus
<jats:named-content content-type="genus-species">Trichoderma</jats:named-content>
(Hypocreales, Ascomycota) are well-known for their production of various secondary metabolites. Nonribosomal peptides and polyketides represent a major portion of these products. In a recent phylogenomic investigation of
<jats:named-content content-type="genus-species">Trichoderma</jats:named-content>
polyketide synthase (PKS)-encoding genes, the
<jats:italic>pks4</jats:italic>
from
<jats:named-content content-type="genus-species">T. reesei</jats:named-content>
was shown to be an orthologue of pigment-forming PKSs involved in synthesis of aurofusarin and bikaverin in
<jats:named-content content-type="genus-species">Fusarium</jats:named-content>
spp. In this study, we show that deletion of this gene in
<jats:named-content content-type="genus-species">T. reesei</jats:named-content>
results in loss of green conidial pigmentation and in pigmentation alteration of teleomorph structures. It also has an impact on conidial cell wall stability and the antagonistic abilities of
<jats:named-content content-type="genus-species">T. reesei</jats:named-content>
against other fungi, including formation of inhibitory metabolites. In addition, deletion of
<jats:italic>pks4</jats:italic>
significantly influences the expression of other PKS-encoding genes of
<jats:named-content content-type="genus-species">T. reesei</jats:named-content>
. To our knowledge, this is the first indication that a low-molecular-weight pigment-forming PKS is involved in defense, mechanical stability, and stress resistance in fungi.
</jats:p>