Figure 10. Disruption of Mdt1 function affects carbon metabolism.

(A) Strains were grown for 10 days on CM or minimal media supplemented with 10 mM of the appropriate carbon and nitrogen source. Like the Δnut1 parental strain, both Δnut1 Supp 321022 extragenic suppressor strains and Δnut1 Δmdt1 double deletion strains were unable to grow on NO₃ ⁻ - containing media. Unlike the Δnut1 parental strain, both MDT1 disruption strains were restored for growth on proline and glucosamine as nitrogen source, indicating T-DNA insertion or homologous gene replacement of MDT1 resulted in carbon derepression in the presence of glucose. (B) Disruption of MDT1 in the Δnut1 background resulted in strains that were carbon catabolite derepressed and significantly reduced in growth on 55 mM glucose+10 mM NH₄ ⁺ minimal media with 100 mM AA compared to growth on NH₄ ⁺ minimal media alone. Single Δmdt1 deletion strains were less sensitive to 100 mM AA on this media.