Genome triplication drove the diversification of Brassica plants  

作　　者：Feng Cheng Jian Wu Xiaowu Wang 

机构地区：[1]Institute of Vegetables and Flowers,Chinese Academy of Agricultural Sciences,Beijing 100081,China

出　　处：《Horticulture Research》2014年第1期190-197,共8页园艺研究（英文）

基　　金：This work was funded by the 973 program(2012CB113900 and 2013CB127000);the 863 program(2012AA100101)and a National Natural Science Foundation of China NSFC grant(31301771);Research was conducted at the Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,Ministry of Agriculture,P.R.China,and the Sino-Dutch Joint Lab of Horticultural Genomics Technology.

摘　　要：The genus Brassica belongs to the plant family Brassicaceae,which includes many important crop species that are used as oilseed,condiments,or vegetables throughout the world.Brassica plants comprise many diverse species,and each species contains rich morphotypes showing extreme traits.Brassica species experienced an extra whole genome triplication(WGT)event compared with the model plant Arabidopsis thaliana.Whole genome sequencing of the Brassica species Brassica rapa,Brassica oleracea and others demonstrated that WGT plays an important role in the speciation and morphotype diversification of Brassica plants.Comparative genomic analysis based on the genome sequences of B.rapa and A.thaliana clearly identified the WGT event and further demonstrated that the translocated Proto-Calepine Karyotype(tPCK,n57)was the diploid ancestor of the three subgenomes in B.rapa.Following WGT,subsequent extensive genome fractionation,block reshuffling and chromosome reduction accompanied by paleocentromere descent from the three tPCK subgenomes during the rediploidization process produced stable diploid species.Genomic rearrangement of the diploid species and their hybridization then contributed to Brassica speciation.The subgenome dominance effect and biased gene retention,such as the over-retention of auxin-related genes after WGT,promoted functional gene evolution and thus propelled the expansion of rich morphotypes in the Brassica species.In conclusion,the WGT event initiated subsequent genomic and gene-level evolution,which further drove Brassica speciation and created rich morphotypes in each species.

关 键 词：subsequent RETENTION initiated 

分 类 号：G89[文化科学—体育学]