A high-quality genome of Actinidia eriantha provides new insight into ascorbic acid regulation

Actinidia eriantha is one of the species with particularly high ascorbic acid (AsA) content in kiwifruit. However, the molecular mechanism of AsA rich in fruit remain unclear. In order to reveal the molecular mechanism of AsA rich in A. eriantha, this study constructed a regulatory network related to AsA metabolism by combining genomics, metabolomics and transcriptomics. Here, we assembled a high-quality genome of A. eriantha 'Ganlv 1' with only five gaps remained. The assembly is comprising of 29 pseudochromosomes with a total size of 615.95 Mb, and contig N50 of 20.35 Mb. Among them, 24 pseudochromosomes were directly from telomere-to-telomere. The LTR assembly index score and consensus quality value were 21.34% and 39.90%, respective. Subsequently, 61 metabolites and 2,092 genes were found to be differentially accumulated/expressed during fruit development by metabolome and transcriptome assay, respectively. For the AsA metabolism, and the cyclic regeneration pathway were observed to the high expression levels throughout the fruit growth and development, suggesting its crucial role in the regulation of AsA. Furthermore, AsA contents are highly associated with ascorbate peroxidase genes. Our genome provides genomic resources for the genetic and breeding research of A. eriantha, and the constructed regulatory network would provide the public data platform for future research on kiwifruit.