MADS-box 基因家族在蒺藜苜蓿的全基因组分析

摘要

MADS-box 基因家族是植物体内的重要转录因子，它们广泛地调控着植物生长、发育和生殖等过程。本研究以蒺藜苜蓿基因组数据为材料，采用结构域搜索方法，鉴定了138个 MADS-box 基因。通过序列比对系统进化分析，将它们分成两大类：Ⅰ型（92个）和Ⅱ型（46个）。同时，通过染色体定位分析发现，134个 MADS-box 基因定位在染色体上，还有4个 MADS-box 基因定位在尚未完成最终拼接的超长片段上。蒺藜苜蓿的 MADS-box 基因家族成员之间存在大量的基因重复，特别是Ⅰ型 MADS-box 基因，通过基因复制，MADS-box 基因家族在染色体上形成多个密集的 MADS-box 基因簇。对蒺藜苜蓿的 RNA-seq 表达谱数据分析，发现 MADS-box 基因在心皮组织、花器官等组织中表达量较高，这表明蒺藜苜蓿的 MADS-box 基因家族广泛地参与苜蓿组织分化、发育以及生殖等过程的调控，这将为进一步揭示 MADS-box 类转录因子在蒺藜苜蓿中作用机制提供了重要的参考。%MADS-box genes encode important transcription factors in plants that are involved in many processes during growth,development and reproduction.A Pfam domain search of the Medicago truncatula genome re-vealed 138 putative MADS-box genes.These genes were classified into two classes,type I (92 members)and type II (46 members),based on multiple alignment and phylogenetic analysis.There were 134 MADS-box genes present on all chromosomes in M.truncatula,while four were located on the super-contigs.Like Arabi-dopsis and rice MADS-box genes,those MADS-box genes expanded through gene duplication events in M. truncatula ,especially the type I genes.There were many duplicate gene clusters,where MADS-box genes with high degrees of similarity were clustered across the M.truncatula genome.Analysis of RNA-seq data from dif-ferent tissues in M.truncatula revealed that MADS-box genes are expressed in seedpod,flower and other tis-sues.This expression pattern suggests that the MADS-box genes play an important role in tissue differentia-tion,development and reproduction process in M.truncatula.