蒺藜苜蓿全基因组中U-box基因家族的筛选与特征分析

植物基因组中广泛存在U-box基因,其编码蛋白大部分作为泛素系统中决定底物特异性识别的E₃泛素连接酶,广泛地调控植物生长生殖发育以及响应逆境胁迫等过程。本文利用蒺藜苜蓿基因组数据库,通过生物信息学手段,鉴定蒺藜苜蓿U-box家族基因;采用MEGA6软件进行系统进化树分析;通过GSDS在线工具和Mapinspect软件进行基因结构及染色体定位分析;利用已有的蒺藜苜蓿芯片数据进行组织表达和胁迫响应表达分析。结果表明,蒺藜苜蓿基因组中含有41个U-box基因,不均匀地分布于蒺藜苜蓿的8条染色体上。根据结构域组成和系统进化分析将这些U-box蛋白分成6类。基因表达模式分析发现,该家族成员的表达具有一定的组织特异性,并能响应盐、干旱和氮素胁迫。这些研究结果为蒺藜苜蓿U-box基因家族的功能分析奠定了基础。

Genome-wide screening and characterization of the U-box gene family in Medicago truncatula

The U-box domain genes typically exist in multiple variants within plant genomes,and most of them belong to the ubiquitin/proteasome system as E3 ubiquitin ligase.They play key roles in the regulation of growth,in development,in reproduction as well as in response to environmental stress.In this study,bioin-formatics methods were applied to identify U-box family genes of M.truncatula through whole genome screen-ing.A phylogenetic tree was created using the MEGA6 program.Gene structure and chromosome location were defined by GSDS and Mapinspect.A total of 41 U-box genes distributed unevenly on 8 chromosomes were identified from M.truncatula.The U-box proteins were classified into six major classes based on their motif compositions and phylogeny relationships.The expression profiles of M.truncatula U-box genes showed char-acteristics of tissue specificity and response to salt,drought and nitrogen stress.These results will be useful for future functional analyses of the U-box family genes in M.truncatula.