摘　要：在甘薯近缘种三浅裂野牵牛（Ipomoea trifida）全基因组水平上对MADS-box基因家族进行鉴定和分析，结果表明，在三浅裂野牵牛基因组中，共鉴定到38个MADS-box（ItfMADS）成员。根据理化性质分析，各成员的氨基酸数目差异很大，有26个成员显碱性。亚细胞定位表明，在这些成员中有32个定位于细胞核。系统进化分析发现，ItfMADS家族可分为Ⅰ型和Ⅱ型2类，Ⅰ型包含9个成员，Ⅱ型包含29个成员。染色体定位分析发现，该38个ItfMADS成员不均匀地分布在三浅裂野牵牛基因组的12条染色体上，其中染色体11（Chr11）上的成员数最多（9个），而Chr12和Chr00仅有1个成员。结构域保守基序分析表明：各成员均含有MADS-box结构域，Ⅱ型的各成员还含有K结构域；motif 1和motif 3是ItfMADS蛋白的重要保守基序。基因结构分析表明，各成员中的内含子和外显子数量差异较大。启动子顺式作用元件分析发现，响应光的顺式作用元件最多。表达模式分析发现，ItfMADS基因在不同的组织中表达存在差异，且在不同胁迫下的表达量也不同，说明ItfMADS基因可能参与了胁迫响应。本研究为甘薯MADS-box基因的功能鉴定提供了参考，也为甘薯的分子育种奠定了基础。
关键词：三浅裂野牵牛；MADS-box；基因组鉴定；组织特异性；表达分析
中图分类号：Q943.2　　　　　　文献标志码：ADOI：10.3969/j.issn.1007-7146.2021.03.005

Abstract: In this study, the MADS-box gene family was identified and analyzed at the genomic level of Ipomoea trifida, a close relative of Ipomoea batatas. The results showed that a total of 38 ItfMADS gene members were identified. According to the analysis of physical and chemical properties, the number of amino acids in each member was very different, and 26 members were alkaline. Subcellular localization indicated that 32 of these members were located in the nucleus. According to the phylogenetic analysis, ItfMADS gene family were divided into type Ⅰ and type Ⅱ. Type Ⅰ consisted of 9 members and type Ⅱ had 29 members. Chromosome localization analysis found that the 38 ItfMADS genes were distributed unevenly on 12 chromosomes. There were 9 members on Chromosome11 (Chr11), while there was only one member on Chr12 and Chr00, respectively. Analysis of conserved domain indicated that all the members contained MADS-box domain, and type Ⅱ members also contained K domain; motif 1 and motif 3 were both important conserved motifs in ItfMADS proteins. Analysis of gene structure showed that the number of introns and exons varied greatly among the 38 ItfMADS genes. Promoter analysis found that cis-acting element of light response were of the most amount. Expression pattern analysis revealed that ItfMADS genes expressed differently in different tissues, and their express responses to different stresses were also different. This study provided a foundation for further functional identification of MADS-box gene of Ipomoea batatas.
Key words: Ipomoea trifida; MADS-box; genome-wide analysis; tissue specificity; expression analysis
（Acta Laser Biology Sinica, 2021, 30(3): 223-235）