The Mechanism Of Metabolic Responses To Ethylene In Blakeslea Trispora

Blakeslea trispora is heterothallic zygote fungi, which is commercially used as natural source of antioxidant ?-carotene in industry. We found that ethylene can promote the production of ?-carotene in B. trispora. In this work, the data of metabolomics and two-dimensional electrophoresis-based proteomics approach were employed, we found that 31 metabolites and 9 proteins were related to the metabolic response to ethylene in B. trispora. Those metabolites and proteins were involved in tricarboxylic acid (TCA) cycle, carbohydrate metabolism, amino acid metabolism, fatty acid metabolism and mevalonate pathway. Our results show that ethylene causes the decrease of TCA flux and the accumulation of acetyl-CoA, which contributes to the enhancement of?-carotene production. At the same time, transcription of key genes involved in mevalonate pathway (including hmgR, ipi, carG, carRA and carB) were induced by ethylene, resulting in the enhancement of ?-carotene production.In order to get a more comprehensive understanding of the transcription regulation in response to ethylene in B. trispora, RNA-Sequencing based gene expression analysis was performed in this study. A total of 27095 transcripts were jointed in B. trispora. The analysis of differentially expressed genes showed that metabolic responses to ethylene in B. trispora mainly happened in stationary phases, and ethylene led to the early presence of stationary phases.The result of KEGG pathway enrichments analysis showed that ethylene caused oxidative stress. We further confirmed that oxidative stress was increased in B. trispora after ethylene treatment by analysis of malondialdehyde level, superoxide dismutase activity and catalase activity.This study provides useful information for ?-carotene productive and understanding the molecular mechanisms of metabolic responses to ethylene in B. trispora.