Changes in morphology can be seen in <i>Aspergillus nidulans</i> FGSC A4 overexpressing <i>pbcR</i> (oe:<i>PbcR</i>).

<p>Pimaradiene gene cluster regulator <i>pbcR</i> was overexpressed in <i>Aspergillus nidulans</i> FGSC A4 (oe:<i>PbcR</i>). Both wild type FGSC A4 and oe:<i>PbcR</i> were grown on potato dextrose plates for 3 days and their morphology studied by microscopy. <b>A)</b> Fewer conidiophores (arrows) are seen in oe:<i>PbcR</i> compared to FGSC A4. Conidiophore structures in both strains were verified at higher magnification (data not shown). Enhanced sexual fruiting body (cleistothecium, dotted circle) formation can be seen in oe:<i>PbcR</i> three-day plate cultures. <b>B)</b> The size of cleistothecia in oe:<i>PbcR</i> is increased compared to FGSC A4 (upper panels), whereas Hülle cell formation around the fruiting body is similar in both strains. The sterigmata of conidiophores in oe:<i>PbcR</i> are darker, and less spores are formed at the tips of the conidiophores than in wild type <i>Aspergillus nidulans</i> (lower panels).