FIGURE 4: Effect of PQ-stress and aging on ROS-scavenging pathways.

(A) Transcriptome data of ROS scavenger enzymes. Colors and numbers indicate relative expression of transcripts of the indicated genes and treatment. Relative expression was calculated by dividing tpm of juvenile PQ-stressed samples by tpm of juvenile control (juv PQ), middle-aged PQ-stressed samples by middle-aged control (ma PQ), senescent PQ-stressed samples by senescent control (sen PQ) and senescent control by juvenile control (aging).

(B,C) The overall SOD activity and H₂O₂ decomposition rate were measured in protein extracts of juvenile (juv), middle-aged (ma) and senescent (sen) P. anserina culturesgrown in PQ-free medium or in medium supplemented with 200 µM PQ.

(B) Overall SOD activity is shown as mean relative expression to the juvenile wild type ± standard error. n = 6. Student’s t test p-values: juv to juv PQ pV = 0.049; juv to sen pV = 0.007.

(C) Besides in wild-type strains (control and PQ), measurement of H₂O₂ decomposition was carried out in a ΔPaCatB strain to estimate the portion of activity related to PaCATB. Data of wild type is shown as mean ± standard error. n = 9 – 11 for wt; n = 1 for ΔPaCatB. Student’s t-test p-values of wild type: juv to sen pV = 0.004; juv to juv PQ pV = 7.05E-5; ma to ma PQ pV = 2.41E-5; sen to sen PQ pV = 0.016.