What makes turnips:anatomy,physiology and transcriptome during early stages of its hypocotyl-tuber development  

作　　者：Mengyang Liu Niccolo Bassetti Stefan Petrasch Ningwen Zhang Johan Bucher Shuxing Shen Jianjun Zhao Guusje Bonnema 

机构地区：[1]Plant Breeding,Wageningen University and Research,Wageningen,the Netherlands [2]Key Laboratory of Vegetable Germplasm Innovation and Utilization of Hebei,Collaborative Innovation Center of Vegetable Industry in Hebei,College of Horticulture,Hebei Agricultural University,Baoding,China [3]Biosystematics Group,Wageningen University and Research,Wageningen,the Netherlands [4]Department of Plant Science,University of California,Davis,CA,USA

出　　处：《Horticulture Research》2019年第1期1364-1377,共14页园艺研究（英文）

基　　金：supported by the China Scholarship Council(CSC,No.201608130113);the work of Ningwen Zhang was financially supported by the Program Strategic Alliances of the Dutch Royal Academy of Sciences(KNAW,PSA program 08-PSA-BD-02).

摘　　要：Brassica species are characterized by their tremendous intraspecific diversity,exemplified by leafy vegetables,oilseeds,and crops with enlarged inflorescences or above ground storage organs.In contrast to potato tubers that are edible storage organs storing energy as starch and are the vegetative propagation modules,the storage organs of turnips,grown from true seed,are swollen hypocotyls with varying degrees of root and stem that mainly store glucose and fructose.To highlight their anatomical origin,we use the term“hypocotyl-tuber”for these turnip vegetative storage organs.We combined cytological,physiological,genetic and transcriptomic approaches,aiming to identify the initial stages,molecular pathways and regulatory genes for hypocotyl-tuber induction in turnips(B.rapa subsp.rapa).We first studied the development of the hypocotyl zone of turnip and Pak choi and found that 16 days after sowing(DAS)morphological changes occurred in the xylem which indicated the early tuberization stage.Tissue culture experiments showed a clear effect of auxin on hypocotyl-tuber growth.Differentially expressed genes between 1 and 6 weeks after sowing in turnip hypocotyls,located in genomic regions involved in tuber initiation and/or tuber growth defined by QTL and selective sweeps for tuber formation,were identified as candidate genes that were studied in more detail for their role in hypocotyl-tuber formation.This included a Bra-FLOR1 paralogue with increased expression 16 DAS,when the hypocotyl starts swelling,suggesting dual roles for duplicated flowering time genes in flowering and hypocotyltuber induction.Bra-CYP735A2 was identified for its possible role in tuber growth via trans-zeatin.Weigthed Coexpression Network Analysis(WGCNA)identified 59 modules of co-expressed genes.Bra-FLOR1 and Bra-CYP735A2 were grouped in a module that included several genes involved in carbohydrate transport and metabolism,cell-wall growth,auxin regulation and secondary metabolism that serve as starting points to illuminate the transcriptiona

关 键 词：ORGANS metabolism ANATOMY 

分 类 号：Q94[生物学—植物学]