Combined Analysis of Transcriptome and Metabolome Reveals the Potential Mechanism of Coloration and Fruit Quality in Yellow and Purple Passiflora edulis Sims

Passion
fruit (Passiflora edulis Sims) can
be divided into yellow
and purple varieties. However, information about coloration and fruit
quality between the two varieties is limited. To reveal the underlying
mechanism of color formation in this fruit, a combined analysis of
the metabolome and transcriptome was conducted in this study. The
results showed that most of the evaluated flavonols, anthocyanins,
and flavanols were significantly upregulated in purple fruit compared
to their levels in yellow fruit. Flavonoid and flavonoid carbonoside
accumulation was markedly higher in yellow fruit than in purple fruit.
The accumulation of organic acids, phenolic acids, lipids, sugars,
and lignans was significantly different in the yellow and purple varieties.
These results were consistent with the results from the RNA-Seq profile.
This study will enable us to identify genes for targeted genetic engineering
to improve the nutritional and market value of passion fruit. In addition,
the peel and pulp of passion fruit contained certain health-promoting
compounds, highlighting the potential application of passion fruit
as a functional food and providing direction for future breeding programs
and production.