摘  要：MLO型基因是植物中特异的一类基因,在植物抗病方面有极大的优势，目前对大豆全基因组MLO基因家族的分析还缺乏相关报道。为了揭示大豆MLO基因的遗传变异及系统发育关系，本文利用生物信息学方法，对其MLO基因家族进行鉴定和分析。结果发现，大豆MLO基因组中含有44个MLO基因家族成员，从GmMLO1-GmMLO44，基因分配到不同的染色体上，串联重复和片段重复有的相同，有的不同，MLO基因含有的正负链也不相同。通过序列比对与系统进行分析，基因蛋白含有保守序列，系统发育关系揭示了这些MLO基因在大豆基因组中并不呈现一一对应关系，表明MLO基因在大豆分化之后发生了扩展和丢失。EST表达分析表明MLO基因广泛参与到大豆的营养生长和生殖生长。MLO基因蛋白很可能是一种类似于G蛋白欧联受体的膜结合转运蛋白而参与到信号传递过程中。本研究结果为进一步鉴定大豆MLO基因并研究其功能奠定了良好的基础。

关键词：大豆；MLO基因；抗病蛋白；生物信息学

Identification and Systematic Analysis of the MLO Gene Family in Soybean (Glycine max L.)

Abstract: MLO gene is a kind of gene specific to plants, which has a great advantage in plant disease resistance. The analysis of the MLO gene family of soybean genome is still lack of relevant reports. In order to reveal the genetic variation and phylogenetic relationships of MLO genes in soybean, the MLO gene family was identified and analyzed by bioinformatics methods. The results showed that soybean MLO genome contains 44 members of MLO gene family, named as GmMLO1-GmMLO44. Analysis of chromosome position of MLO genes showed that 44 GmMLO genes were localized on different positions, but fragment duplication and tandem duplication control the expansion of GmMLO family genes in soybean. By sequence alignment and system analysis, gene protein contains a conserved sequence, and phylogenetic relationships reveal the MLO genes in soybean genome does not appear to be a one-to-one relationship, indicating that MLO gene in soybean differentiation after the expansion and loss. EST expression analysis showed that MLO gene was widely involved in vegetative growth and reproductive growth of soybean. The MLO gene is likely to involve in the membranes of G-protein-coupled receptor binding protein transport and participate in signal transmission process. The results of this study laid a good foundation for further identification of soybean MLO gene and its function.

Key words: Soybean; MLO gene; Disease resistance protein; Bioinformatics

目    录

摘要 1

引言 2

1 材料与方法 2

 1.1物种选定与序列下载 2

 1.2 序列比对与系统进化分析.....................3

 1.3 蛋白保守基序与功能结构域分析.......... ..........  ..3

 1.4 基因染色体定位与扩增模式分析 3

 1.5 基因时空表达分析 3

2 结果与分析4

 2.1大豆MLO家族基因的鉴定....................4

 2.2 大豆与模式植物MLO家族基因的系统进化关系................... 5

 2.3 大豆MLO家族蛋白的保守基序与功能结构域征................... 7

 2.4 大豆MLO基因家族成员的染色体定位与扩增模式................... 8

 2.5 大豆MLO基因家族成员的时空表达规律................... 9

3 讨论与结论  10

参考文献  11

附录  13

致谢 14

大豆MLO家族基因的鉴定与系统性研究

引言

植物在长期的进化过程中形成了一系列复杂而严密的防御机制，使自身免受病原物的侵害，自身产生抗病抗体，其中涉及到一系列抗病相关基因的表达和调控。抗白粉病基因是植物防御体系中的最重要组成部分。MLO是植物中特有的一类基因家族，具有完整的7个跨膜结构域[1-4]，可能起到与G蛋白欧联受体类似的功能。