水稻(Oryza sativa L.)α-淀粉酶基因的进化及组织表达模式  

Characterization of Evolution and Tissue-Expression of Rice (Oryza sativa L.) α-Amylase Genes

作　　者：廖登群[1,2] 张洪亮[1] 李自超[1] John BENNETT 

机构地区：[1]中国农业大学/农业部作物基因组学与遗传改良重点实验室/北京市作物遗传改良重点实验室,北京100193 [2]Plant Breeding,Genetics and Biotechnology Division,International Rice Research Institute [3]School of Biological Sciences,University of Sydney

出　　处：《作物学报》2010年第1期17-27,共11页Acta Agronomica Sinica

基　　金：2003 Theme 1 Budget of the Challenge Program for Water and Food;国家高技术研究发展计划(863计划)项目(2006AA10Z158)资助

摘　　要：α-淀粉酶在植物特别是谷类萌发种子淀粉降解中具有重要作用。水稻α-淀粉酶基因的结构、进化和表达研究已有报道,但多集中于OsAmy1和OsAmy3这两个亚族内基因间以及发芽种子中。不同亚族间的基因结构、进化及更多组织和时期的表达特点尚缺乏细致研究。本研究通过TblastN同源性比对及保守结构域分析揭示水稻基因组含有11个α-淀粉酶基因。生物信息学分析、系统进化树构建及半定量RT-PCR分析表明,该家族基因在结构上发生了明显的分化,具有清晰的进化层次,OsAmy5A和OsAmy4A是家族中较原始状态的基因;在表达和功能上也发生了明显分化,进化水平较高的基因发生了明显的时空表达特异性分化。OsAmy1A、OsAmy3A及OsAmy3D和OsAmy3E分别在保证种子植物世代传递、维持种子休眠过程中胚的微弱生命活动及保证种子萌发过程中能量的稳定持续供应上具有重要作用。α-amylases play an important role in starch degradation in plants, especially in cereal germinating seeds. Existing re- ports on structural organization and evolution of rice α-amylase family mainly focus on members of subfamilies OsAmyl and OsAmy3 and their expression in germinating seeds, however, it is not known whether the putative α-amylase genes else exist in rice genome and what their structural organization, evolution and expression profiling look like especially among subfamilies. Via TblastN search and conservative domain analysis, we revealed that there were 11 putative α-amylase genes in rice genome. Through tools of bioinformatics, phylogenetic reconstruction and semi-quantitative RT-PCR, we studied the structural evolution among these 11 α-amylase genes and their spatial-temporal expression profiling. The results showed that there was a distinctly divergent and ranked gene structure among members of this family. OsAmy5A and OsAmy4A were the most primitive genes, and other ones were evolved from them mainly through loss of introns and fixed more conserved domains and sequences. These genes were also divergent in expression and function. The more primitive the genes are the less spatial-temporal specificity in gene ex- pression they have. OsAmy5A, OsAmy4A, and OsAmy2A were expressed in all tissues, however, the rest were expressed spatially and temporally. OsAmylA, which was expressed at the beginning of seed germination but not all during the grain filling stage, should serve to control energy supply between generations. OsAmy3A, both expressed dramatically at the end of grain filling and the initiation of seed germination, should be related to sustaining life activities in embryos of dormancy seeds. OsAmy3D and OsAmy3E were regulated at the gene expression level by sugar concentration during seed germination, and may play an important role in stable and continuous energy supply during seed germination.

关 键 词：水稻 Α-淀粉酶 基因结构 进化 表达 

分 类 号：S511[农业科学—作物学]