【摘要】 β-酮脂酰辅酶A合成酶(β-ketoacyl-CoA synthase，KCS)是超长链脂肪酸合成中的限速酶，通过对大白菜KCS基因家族鉴定分析，为揭示KCS在控制大白菜蜡质性状中的具体功能研究奠定了基础。利用生物信息学的分析方法鉴定大白菜KCS基因家族成员，分析其亲缘关系、蛋白质理化性质、染色体定位、共线性关系、基因结构、蛋白保守域结构和基因表达模式。从大白菜全基因组共鉴定到32个BrKCS基因成员分成4个亚组，不均匀地分布在10条染色体上。BrKCS氨基酸长度和分子量的范围分别为181-755 aa和20.54-84.83 kD。共线性分析表明BrKCS5、BrKCS8和BrKCS13等7个家族成员与拟南芥共线性的BrKCS基因发生两倍化，1个家族成员(BrKCS9)发生了三倍化。基因结构分析显示，不同成员编码的氨基酸序列外显子数目及位置存在差异。转录组分析表明，BrKCS5、BrKCS6b与BrKCS10b基因在大白菜不同器官/组织尤其在花器官中可能参与蜡粉的合成。qRT-PCR分析结果验证了转录组数据的可靠性。综上所述，从大白菜全基因组共鉴定到32个BrKCS，其中3个基因在蜡粉近等基因系中表达量高且差异显著，为解析BrKCS基因在控制大白菜蜡质性状中的分子机制奠定了基础。更多还原

【Abstract】 β-ketoacyl-CoA synthase(KCS)is a rate-limiting enzyme in the synthesis of very long chain fatty acids.Identification and analysis of KCS gene family lays a foundation for revealing the specific function in controlling the wax characters of Chinese cabbage(Brassica rapa).The members of Chinese cabbage KCS gene family were identified by bioinformatics method，and their genetic relationship，protein physical and chemical properties，chromosome location，collinearity，gene structure，protein conserved domain structure and gene expression pattern were analyzed.A total of 32 BrKCS gene members were identified from the whole genome of Chinese cabbage.Phylogenetic analysis indicated that these BrKCS genes were divided into 4 subgroups，which were unevenly distributed on 10 chromosomes.The amino acid length and molecular weight of BrKCS proteins ranged from 181 to 755 aa and 20.54 to 84.83 kD，respectively.Collinearity analysis showed that 7 family members such as BrKCS5，BrKCS8 and BrKCS13 doubled with the BrKCS gene of Arabidopsis，and one family member(BrKCS9)tripled.Gene structure analysis showed that the number and location of exons of amino acid sequences encoded by different members were different.Transcriptome analysis showed that BrKCS5，BrKCS6b and BrKCS10b genes played an important role in controlling waxy characters in different organs/tissues of Chinese cabbage，especially in flower organs.qRT-PCR analysis verified the reliability of transcriptome data.In conclusion，a total of 32 BrKCS were identified from the whole genome of Chinese cabbage，of which three genes were highly expressed and significantly different in waxy near-isogenic lines，laying a foundation for analyzing the molecular mechanism of BrKCS gene in controlling Chinese cabbage wax traits.更多还原