Media release

From: Springer Nature

Investigating the orange-ins of citrus fruits

The assembly of 12 genomes of fruits from the orange subfamily are reported in Nature Genetics. The findings provide insights into the origin and evolution of this subfamily and the genetic basis of flavour in citrus fruits.

The orange subfamily comprises hundreds of species — including oranges, lemons, limes and grapefruit — many of which that are widely cultivated. However, the origin and evolution of the orange subfamily, and the genetic basis of variation in fruit flavour, are unclear.

Qiang Xu and colleagues analysed the genomes of 314 members of the orange subfamily and assembled the genomes of 12 species. They suggest that the ancient Indian Plate was likely the ancestral area for Citrus-related genera, and that South Central China was the primary centre of origin for the Citrus genus. The authors also explored the genetic basis that underlies variations in citric acid content — a key component for fruit flavour. They found that the PH4 gene has a key role in the accumulation of citric acid in citrus fruits.

The findings shed light on the evolution of the orange subfamily, the regulatory mechanisms that underlie citrus fruit flavours, and provide genomic resources for future research.