Analysis of the mechanism of tripropylamine-enhanced lycopene accumulation in Blakeslea trispora through transcriptome.

Abstract

Lycopene is a carotenoid with strong antioxidant properties. Treatment with tripropylamine (TPA) greatly increases lycopene production by Blakeslea trispora, but the mechanism of this effect remains unclear. In this study, a reference-free transcriptome was used to analyze changes in gene expression in B. trispora after treatment with TPA. Downregulated genes were mostly involved in primary and secondary metabolic pathways, whereas upregulated genes were mostly related to autophagy and nucleotide excision repair. In addition, after TPA treatment, the mycelium swelling and the number of spores decreased. Our study suggests that TPA causes DNA damage, which upregulates the expression of nucleotide excision repair genes Xpb, Xpg, Csb, Polr2, and genome stability regulator gene Rmi1, as well as downregulation of Lsm2 and Dars2 and upregulation of G10, which are related to mRNA spliceosomes, leaving the cell in a state of starvation and triggering lysosomal-, peroxisomal-, and vacuole-autophagy. The autophagosome recycles material from spores, reduces spore production, and induces mycelial swelling, which, in turn, increases lycopene production and storage.