1.Tung Tree (Vernicia fordii) Genome ProvidesA Resource for Understanding Genome Evolution and Improved Oil Production
Zhang LIN ; Liu MEILAN ; Long HONGXU ; Dong WEI ; Pasha ASHER ; Esteban EDDI ; Li WENYING ; Yang XIAOMING ; Li ZE ; Song AIXIA ; Ran DUO ; Zhao GUANG ; Zeng YANLING ; Chen HAO ; Zou MING ; Li JINGJING ; Liang FAN ; Xie MEILI ; Hu JIANG ; Wang DEPENG ; Cao HEPING ; Provart J. NICHOLAS ; Zhang LIANGSHENG ; Tan XIAOFENG
Genomics, Proteomics & Bioinformatics 2019;17(6):558-575
Tung tree (Vernicia fordii) is an economically important woody oil plant that produces tung oil rich in eleostearic acid. Here, we report a high-quality chromosome-scale genome sequence of tung tree. The genome sequence was assembled by combining Illumina short reads, Pacific Bio-sciences single-molecule real-time long reads, and Hi-C sequencing data. The size of tung tree gen-ome is 1.12 Gb, with 28,422 predicted genes and over 73% repeat sequences. The V. fordii underwent an ancient genome triplication event shared by core eudicots but no further whole-genome duplication in the subsequent ca. 34.55 million years of evolutionary history of the tung tree lineage. Insertion time analysis revealed that repeat-driven genome expansion might have arisen as a result of long-standing long terminal repeat retrotransposon bursts and lack of efficient DNA deletion mechanisms. The genome harbors 88 resistance genes encoding nucleotide-binding sites;17 of these genes may be involved in early-infection stage of Fusarium wilt resistance. Further, 651 oil-related genes were identified, 88 of which are predicted to be directly involved in tung oil biosynthesis. Relatively few phosphoenolpyruvate carboxykinase genes, and synergistic effectsbetween transcription factors and oil biosynthesis-related genes might contribute to the high oil content of tung seed. The tung tree genome constitutes a valuable resource for understanding genome evolution, as well as for molecular breeding and genetic improvements for oil production.