Two haplotype-resolved,gap-free genome assemblies for Actinidia latifolia and Actinidia chinensis shed light on the regulatory mechanisms of vitamin C and sucrose metabolism in kiwifruit  

作　　者：Xue Han Yilin Zhang Qiong Zhang Ni Ma Xiaoying Liu Wenjing Tao Zhiying Lou Caihong Zhong Xing Wang Deng Dawei Li Hang He 

机构地区：[1]Peking University Institute of Advanced Agricultural Sciences,Shandong Laboratory of Advanced Agricultural Sciences in Weifang,Shandong 261325,China [2]School of Advanced Agricultural Sciences and School of Life Sciences,Peking University,Beijing 100871,China [3]Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture,Wuhan Botanical Garden,The Chinese Academy of Sciences,Wuhan,Hubei 430074,China [4]State Key Laboratory of Cellular Stress Biology,School of Life Sciences,Faculty of Medicine and Life Sciences,Xiamen University,Xiamen 361102,China

出　　处：《Molecular Plant》2023年第2期452-470,共19页分子植物（英文版）

基　　金：supported by the Provincial Technology Innovation Program of Shandong;an award from the Natural Science Foundation of Shandong Province(ZR2021ZD30);the Director’s Award from the Peking University Institute of Advanced Agricultural Sciences,the National Top Young Talents Program of China;the Boya Postdoctoral Program of Peking University,the National Key R&D Program of China(2019YFD1000200);the Youth Innovation Promotion Association CAS(2018376).

摘　　要：Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two telomere-to-telomere kiwifruit genomes from Actinidia chinensis var.‘Donghong’(DH)and Actinidia latifolia‘Kuoye’(KY),with total lengths of 608327852 and 640561626 bp for 29 chromosomes,respectively.With a burst of structural variants involving inversion,translocations,and duplications within 8.39 million years,the metabolite content of DH and KY exhibited differences in saccharides,lignans,and vitamins.A regulatory ERF098 transcription factor family has expanded in KY and Actinidia eriantha,both of which have ultra-high vitamin C content.With each assembly phased into two complete haplotypes,we identified allelic variations between two sets of haplotypes,leading to protein sequence variations in 26494 and 27773 gene loci and allele-specific expression of 4687 and 12238 homozygous gene pairs.Synchronized metabolome and transcriptome changes during DH fruit development revealed the same dynamic patterns in expression levels and metabolite contents;free fatty acids and flavonols accumulated in the early stages,but sugar substances and amino acids accumulated in the late stages.The AcSWEET9b gene that exhibits allelic dominance was further identified to positively correlate with high sucrose content in fruit.Compared with wild varieties and other Actinidia species,AcSWEET9b promoters were selected in red-flesh kiwifruits that have increased fruit sucrose content,providing a possible explanation on why red-flesh kiwifruits are sweeter.Collectively,these two gap-free kiwifruit genomes provide a valuable genetic resource for investigating domestication mechanisms and genome-based breeding of kiwifruit.

关 键 词：KIWIFRUIT GENOME telomere-to-telomere allele-specific expression vitamin C sugar metabolism 

分 类 号：S663[农业科学—果树学]