The telomere-to-telomere genome of Sanicula chinensis unveils genetic underpinnings of low furanocoumarin diversity and content in one basal lineage of Apiaceae.

Abstract

Furanocoumarins are specialized defense compounds in Apiaceae, but the evolutionary path of their biosynthesis is not well understood. We generated a telomere-to-telomere (T2T) genome for Sanicula chinensis, an early-diverging species within the Saniculoideae subfamily, to explore its evolution. Comparative genomics revealed that S. chinensis and Apioideae species each underwent unique whole-genome duplication (WGD). Unlike most species in the Apioideae subfamily, S. chinensis produces a limited diversity and content of furanocoumarins but shows high esculetin levels. This metabolic profile likely stems from three genetic factors: elevated expression of p-Coumaroyl ester 3'-hydroxylase (C3'H) and hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT), which shift the metabolic pathway toward simple coumarins; the absence of a key biosynthetic gene cluster, including prenyltransferase (PT) and p-coumaroyl-CoA 2'-hydroxylase (C2'H), found in Apioideae; and incomplete or inactive PT enzymes in S. chinensis. Our results not only shed light on the evolutionary history of furanocoumarin biosynthesis in Apiaceae, but also provide avenues for tailoring furanocoumarin content for agricultural or medical applications in plants.