菠萝是多年生热带草本果树，深入研究其体细胞胚发生的分子调控机理对推动工厂化育苗有着重要意义。体细胞胚发生始于从体细胞到胚性细胞的转变，而 SERK基因的特异表达在这一过程中起着重要的信号转导作用，但国内外尚未见对其表达调控分子机制的报道。本课题组研究表明，菠萝有3个SERK基因家族成员，只有AcSERK1基因参与了体细胞胚诱导，其 5`上游-1137/-722区具有胚性细胞特异性调控功能、-227/-1区具有基础转录活性，两个区域配合启动AcSERK1基因在菠萝体细胞胚发生初期发生大量表达， 5`上游区存在2个CpG岛。本申请将在上述基础上，继续分离AcSERK1基因的胚性细胞特异性序列、筛选和鉴定与该序列互作的转录因子、分析5`上游甲基化对转录的影响，解析该基因在菠萝体细胞发生初期特异性表达的分子机制，为进一步研究该基因表达调控网络和有效调菠萝体细胞发生打下基础。

Pineapple (Ananas comosus (L.) Merr.） a perennial herbaceous fruit tree, is widely-spreaded and cultivated in tropical region. It will be of great importance for the genetic improvement and industrial breeding of pineapple to study the molecular mechanism of its somatic embryogenesis (SE) regulation. SE starts with the conversion from somatic cell to embryogenic cell. During this transition phase, a stage-specifically expressing gene, AcSERK1 played a key role in signal transduction. However, there is no research reporting about the molecular mechanism of its expressiong regulation. Our previous works showed that AcSERK is a gene family consisting of 3 members. Only AcSERK1 participates in induction of SE, and its 5′ upstream region between nt -1137 /-722 was supposed to possess embryogenic cell specific regulatory function. Besides, the sub-sequences between nt -227 / -1 had the basal transcriptional activity, which contains 2 CpG islands, these two regions interacted with each other to play an important role to started the stage-specific expression pattern of AcSERK1 during the early of SE in the pineapple. Based on these results, the present project will isolate and identify the embryogenic cell specific cis-element and then select and characterize the transcription factor which interact with the specific cis-element . In addition, we will also analyze the impact of different methylation levels of AcSERK1 5'-upstream region on its transcription activity. Summary above, we would clarify the molecular mechanism undelying regulation of AcSERK1 gene during the early of SE, expecting to what metioned above will be the foundation of further study for analyzing transcription factors and afford an efficient way to regulate the somatic embryogenesis.