Oxidative stress is induced in many organisms by various natural abiotic factors including irradiation. It has been demonstrated that it significantly improves growth rate and lipid production of Rhodotorula glutinis. However, the specific mechanism of how irradiation influences the metabolism of R. glutinis remains still unavailable. To investigate and better understand the mechanisms involved in irradiation-induced stress resistance in R. glutinis, a multi-omics metabolism analysis was implemented. The results confirmed that irradiation indeed not only improved cell biomass but also accelerated the production of carotenoids and lipids, especially neutral lipid. Compared with the control, metabolome profiling in the group exposed to irradiation exhibited an obvious difference in the activation of the tricarboxylic acid cycle and triglyceride (TAG) production. The results of proteome analysis (data are available via ProteomeXchange with identifier PXD009678) showed that 423 proteins were changed significantly, and proteins associated with protein folding and transport, the Hsp40 and Sec12, were obviously upregulated, indicating that cells responded to irradiation by accelerating the protein folding and transport of correctly folded proteins as well as enhanced the degradation of misfolded proteins. A significant upregulation of the carotenoid biosynthetic pathway was observed which revealed that increased carotenoid content is a cellular defense mechanism against oxidative stress generated by irradiation. Therefore, the results of comprehensive omics analysis provide intensive insights on the response mechanism of R. glutinis to irradiation-induced oxidative stress which could be helpful for using irradiation as an effective strategy to enhance the joint production of the neutral lipid and carotene.
Keywords: Irradiation; Multi-omics analysis; Rhodotorula glutinis; Stress response.