Molecular Regulation of Carotenoid Accumulation Enhanced by Oxidative Stress in the Food Industrial Strain Blakeslea trispora

<i>Blakeslea trispora</i> is a key industrial strain for carotenoid production due to its rapid growth, ease of cultivation, and high yield. This study examined the effects of oxidative stress induced by rose bengal (RB) and hydrogen peroxide (H₂O₂) on carotenoid accumulation, achieving maximum yields of 459.38 ± 77.15 μg/g dry cell weight (DCW) at 0.4 g/L RB and 294.38 ± 14.16 μg/g DCW at 0.6% H₂O₂. These results demonstrate that oxidative stress promotes carotenoid accumulation in <i>B. trispora</i>. To investigate the underlying molecular mechanisms, transcriptional levels of key genes were analyzed under optimal stress conditions. In the carotenogenic pathway, only <i>HMGR</i> showed upregulation, while <i>ACC</i>, linked to fatty acid biosynthesis, remained unchanged. Within the mitogen-activated protein kinase (MAPK) pathway, <i>FUS3</i> transcription increased under both stress conditions, <i>MPK1</i> transcription rose only under H₂O₂ stress, and <i>HOG1</i> exhibited no significant changes. Among heat shock proteins (HSPs), only <i>HSP70</i> showed elevated transcription under H₂O₂ stress, while other <i>HSP</i> genes remained unchanged. These findings suggest that oxidative stress induced by RB and H₂O₂ enhances carotenoid accumulation in <i>B. trispora</i> through distinct regulatory pathways. This study provides valuable insights into stress-adaptive mechanisms and offers strategies to optimize carotenoid production in fungi.