The effect of ethylene on squalene and β-sitosterol biosynthesis and its key gene network analysis in Torreya grandis nuts during post-ripening process

Squalene and beta-sitosterol are health-benefit compounds due to their nutritional and medicinal properties. It has been reported that the content of these bioactive compounds is relatively high in Torreya grandis nuts. However, it is not yet known what changes in squalene and beta-sitosterol accumulation occur during the special post-ripening process of T. grandis nuts and the effect of the well-known ripening hormone ethylene on the regulatory mechanism of their biosynthetic pathways. Thus, we performed transcriptome and metabolite analyses. The results showed that ethylene not only promoted the post-ripening process but also enhanced the accumulation of squalene by inducing gene expression in the mevalonate pathway. At the same time, ethylene treatment also promoted the accumulation of other sterols but inhibited gene expression in the beta-sitosterol biosynthesis pathway. In addition, co-expression and correlation analysis suggested a framework for the transcriptional regulation of squalene and beta-sitosterol biosynthesis genes under ethylene treatment.

Automated summary

Research found that ethylene not only promoted the post-ripening process of Torreya grandis nuts, but also increased the accumulation of squalene by inducing gene expression in the mevalonate pathway. Additionally, ethylene treatment enhanced the accumulation of other sterols while inhibiting gene expression in the beta-sitosterol biosynthesis pathway. Co-expression and correlation analysis revealed a regulatory framework for the transcriptional regulation of squalene and beta-sitosterol biosynthesis genes under ethylene treatment.