Abstract: ABC1 (Activity of bc1 complex) family belongs to protein kinase families, whose members widely exist in prokaryotes and eukaryotes. It has been reported that several plant ABC1 genes participate in abiotic stress response. To understand the structure and function of ABC1 genes in rice, the systematic characterization of rice and Arabidopsis ABC1 genes and the expression analysis of rice ABC1 genes were performed. A total of 15 and 17 members of rice and Arabidopsis ABC1 families were identified by the bioinformatics method. The phylogenetic analysis of these proteins suggested that divergence of this family had occurred and the main characteristics had established before the dicotmonocot split; speciesspecific expansion contributed to the evolution of this family in rice and Arabidopsis after the split of monocots and dicots. Intron/exon stucture analysis indicated that most of the orthologous genes had similar exon sizes but diverse intron sizes and the rice genes contained more large introns; intron gain was an important event accompanying the recent evolution of rice ABC1 family. Multiple sequence alignment revealed one conserved amino acid segment and four conserved amino acids of the ABC1 domain. Online subcellular localization predicted that nine rice ABC1 proteins were localized in the chloroplast. Realtime RTPCR assay established that rice ABC1 genes expressed primarily in leaves and could be modulated by a broad range of abiotic factors such as H2O2, abscisic acid, low temperature, drought, darkness and high salinity. These results illustrate that rice ABC1 family played roles not only in the environmental stress response but also likely in the specific biological process of rice.

摘要： ABC1（Activity of bc1 complex）家族属于蛋白质激酶家族，其成员普遍存在于原核和真核生物中。已有研究表明，几个植物ABC1基因参与非生物胁迫应答。为了解ABC1基因在水稻中的结构和功能，采用生物信息学方法分别在水稻和拟南芥上鉴定出15个和17个ABC1基因，并进行了系统发育和表达分析。结果表明，该家族在单、双子叶植物分离之前就已经发生了分化，其基本特征已经形成；单、双子叶植物分离之后，该家族在水稻和拟南芥中均以物种特异的方式进行了扩增。内含子/外显子结构分析显示多数直系同源基因之间外显子大小接近，而内含子差别较大，水稻含有更多大的内含子；内含子获得是近期伴随水稻ABC1家族进化的重要事件。多序列比对显示，ABC1结构域具有1个保守的氨基酸片段和4个保守的氨基酸残基。在线亚细胞定位预测9个水稻ABC1蛋白定位在叶绿体上。实时定量RT-PCR分析表明，水稻ABC1基因主要在叶片中表达，并且受多种非生物胁迫因素包括H₂O₂、脱落酸、低温、干旱、黑暗和高盐的调控。说明水稻ABC1家族不仅在逆境胁迫应答中发挥重要作用，可能还与水稻特定的生理过程有关。